If you think that low fat means low calories, read on. Often, reduced fat items have more sugar added to enhance the flavor, which contributes calories to the final product. Also, many of us think that by eating the low fat version of a food, we can eat more of it. If you are watching your weight, this will only sabotage your efforts.
Check out the list of foods below to see the difference in calories (if there is any) between common low fat and regular fat foods.
Low-fat or Fat-free Regular
Reduced Fat Peanut Butter Regular Peanut Butter
2 Tbsp: 190 calories, 12g fat 2 Tbsp: 190 calories, 16g fat
Low Fat Wheat Thins Regular Wheat Thins
16 crackers: 130 calories, 4g fat 16 crackers: 150 calories, 6g fat
Low Fat Oreos Original Oreos
3 cookies: 150 calories, 4.5g fat 3 cookies: 160 calories, 7g fat
Fat Free Fig Newtons Regular Fig Newtons
2 cookies: 100 calories, 0g fat 2 cookies: 110 calories, 2g fat
Low fat Fruit-flavored Yogurt Regular Fruit-flavored Yogurt
6 oz: 173 calories, 1.8 g fat 6 oz: 170 calories, 6 g fat
Light Tortilla Chips Regular Granola Cereal
1 oz: 132 calories, 4.3g fat ½ cup: 210 calories, 6g fat
Low fat Granola Cereal Regular Tortilla Chips
½ cup:160 calories, 2.2g fat 1 oz: 141 calories, 7.3g fat
Fat Free Apple Cinnamon Muffin Regular Apple Cinnamon Muffin
Small: 130 calories, 0g fat Small: 147 calories, 6.9g fat
The Bottom Line:
Although it is a good idea to limit your fat intake, you can see that sometimes there is not much of a calorie difference between the low fat (or fat free) version of a food compared to its regular version. So, what are you to do? If you like the taste of a particular higher fat food, limit your calories by controlling your portion. If you think that eating low fat or fat free foods permits you to eat more of a specific food, think again!
Monday, October 15, 2007
5 Simple Ways to Lose Weight,without feeling deprived
Is losing weight one of your new year's resolutions? Following a fad diet, or being overly restrictive, will not help your achieve your long-term weight goals. Instead, taking simple yet sensible steps may help you lose weight without feeling deprived.
5 Simple Ways to lose weight
Don't drink CaloriesSweetened beverages such as pop, juice drinks, coffee drinks and tea may satisfy your thirst, but give you lots of empty calories. What's worse is that, unlike eating solid food, drinking liquid calories doesn't make you feel full so you won't eat less food afterwards. Simply cutting a can of pop a day can help you lose 15 pounds in a year! Diet or zero-calorie pop offers no nutritional values either - it's just water added with artificial sweeteners and caffeine. Drink water instead. Carrying a bottle of water with you will encourage you sip it instead of reaching for sweetened beverages.
Snack SensiblyInstead of regarding snacks as a treat in order to lose weight, regard them as a filler. Plan your snacks to fill the nutritional gap other meals may miss. For instance, if you do not eat enough calcium-rich foods at your three big meals, have a low-fat yogurt as snacks. If you do not eat enough whole grains, have a small whole-wheat sandwich. The key in your fight to lose weight is to plan your snacks ahead instead of letting your vending machine limit your choices. Good snack options include low-fat dairy, fruit, nuts, light popcorn and baked goods made with whole grains. In addition, don't snack just because everyone else in your office is or when you have nothing to do in front of the TV; snack only when you are hungry.
Fill your plate with VegetablesVegetables, especially the bright colored and dark green leafy ones, are loaded with vitamins and antioxidants and will help you lose weight. They are also high in fiber and hence very filling. In addition, they are low in calories - good to help lose weight and trim your waistline. When you fill up your stomach with veggies, you will less likely feel the urge to binge on meats and other desserts later on.
Eat BreakfastPeople often skip breakfast. Some skip it because they are often too rushed in the morning and have little time to prepare. Some people skip it as a measure to maintain or lose weight. Studies have shown that people who eat breakfast regularly actually are more easily able to control their weight than those who skip breakfast. Often times, skipping a meal results in an increased total caloric intake than if we just ate more frequently throughout the course of the day.
Stop when you are fullDo you continue to pour gasoline in your car even though it is full? If not, why do so to your own body? Our body is capable of sending satiety signal, so stop eating when you are full. Don't overeat for the sake of finishing the plate. If you feel guilty about wasting foods, simply doggie-bag it and save it for later.
Is losing weight one of your new year's resolutions? Following a fad diet, or being overly restrictive, will not help your achieve your long-term weight goals. Instead, taking simple yet sensible steps may help you lose weight without feeling deprived.
5 Simple Ways to lose weight
Don't drink CaloriesSweetened beverages such as pop, juice drinks, coffee drinks and tea may satisfy your thirst, but give you lots of empty calories. What's worse is that, unlike eating solid food, drinking liquid calories doesn't make you feel full so you won't eat less food afterwards. Simply cutting a can of pop a day can help you lose 15 pounds in a year! Diet or zero-calorie pop offers no nutritional values either - it's just water added with artificial sweeteners and caffeine. Drink water instead. Carrying a bottle of water with you will encourage you sip it instead of reaching for sweetened beverages.
Snack SensiblyInstead of regarding snacks as a treat in order to lose weight, regard them as a filler. Plan your snacks to fill the nutritional gap other meals may miss. For instance, if you do not eat enough calcium-rich foods at your three big meals, have a low-fat yogurt as snacks. If you do not eat enough whole grains, have a small whole-wheat sandwich. The key in your fight to lose weight is to plan your snacks ahead instead of letting your vending machine limit your choices. Good snack options include low-fat dairy, fruit, nuts, light popcorn and baked goods made with whole grains. In addition, don't snack just because everyone else in your office is or when you have nothing to do in front of the TV; snack only when you are hungry.
Fill your plate with VegetablesVegetables, especially the bright colored and dark green leafy ones, are loaded with vitamins and antioxidants and will help you lose weight. They are also high in fiber and hence very filling. In addition, they are low in calories - good to help lose weight and trim your waistline. When you fill up your stomach with veggies, you will less likely feel the urge to binge on meats and other desserts later on.
Eat BreakfastPeople often skip breakfast. Some skip it because they are often too rushed in the morning and have little time to prepare. Some people skip it as a measure to maintain or lose weight. Studies have shown that people who eat breakfast regularly actually are more easily able to control their weight than those who skip breakfast. Often times, skipping a meal results in an increased total caloric intake than if we just ate more frequently throughout the course of the day.
Stop when you are fullDo you continue to pour gasoline in your car even though it is full? If not, why do so to your own body? Our body is capable of sending satiety signal, so stop eating when you are full. Don't overeat for the sake of finishing the plate. If you feel guilty about wasting foods, simply doggie-bag it and save it for later.
Shopping and eating tips for
Shopping and eating tips for lower fat eating
>Vegetable oils, lard, shortening and table fats like butter, margarine, mayonnaise, and salad dressing are high fat items. Buy less and use less. Choose fat-reduced brands whenever you can.
When you cook and bake, reduce the amount of fat called for in recipes. Look for lower-fat recipes and ideas to reduce the fat in traditional recipes.
>Buy milk, cottage cheese, and yogurt that contains no more than 2% butterfat. The lower the fat, the better. Read more about Yogurt here.
>Buy lower fat cheese (15% B.F or less) for regular use and keep the richer cheese (30% or more) for special occasions.
>Buy the leanest cuts of meat and eat only the recommended portion sizes (~3oz per meal). Trim all visible fat from meat before cooking. Include more fish and legumes in your diet.
>When you cook meats, avoid adding extra fat. Use non-stick pans for stir-frying and use a little broth or juice to prevent sticking at the start of cooking.
>Reduce the amount of baked goodies and snack items that you buy. Choose lower fat cookie choices like: arrowroot biscuits; social tea biscuits; ginger snaps; sultana and newton-type cookies. Pretzels and popcorn are lower fat alternatives to chips, cheese flavored snacks or corn chips.
>Choose carefully in restaurants. Most restaurant chains have lower calorie, lower fat options from which to choose.
>The value for total fat is a key piece of fat information on the label Although there is a lot of publicity given to the pros and cons of the various types of fat, it is becoming clear that the effects of the various types of fat aren't as simple and predictable as once thought. For this reason, total fat remains the most useful fat information. When comparing brands choose the lower fat product.
>Vegetable oils, lard, shortening and table fats like butter, margarine, mayonnaise, and salad dressing are high fat items. Buy less and use less. Choose fat-reduced brands whenever you can.
When you cook and bake, reduce the amount of fat called for in recipes. Look for lower-fat recipes and ideas to reduce the fat in traditional recipes.
>Buy milk, cottage cheese, and yogurt that contains no more than 2% butterfat. The lower the fat, the better. Read more about Yogurt here.
>Buy lower fat cheese (15% B.F or less) for regular use and keep the richer cheese (30% or more) for special occasions.
>Buy the leanest cuts of meat and eat only the recommended portion sizes (~3oz per meal). Trim all visible fat from meat before cooking. Include more fish and legumes in your diet.
>When you cook meats, avoid adding extra fat. Use non-stick pans for stir-frying and use a little broth or juice to prevent sticking at the start of cooking.
>Reduce the amount of baked goodies and snack items that you buy. Choose lower fat cookie choices like: arrowroot biscuits; social tea biscuits; ginger snaps; sultana and newton-type cookies. Pretzels and popcorn are lower fat alternatives to chips, cheese flavored snacks or corn chips.
>Choose carefully in restaurants. Most restaurant chains have lower calorie, lower fat options from which to choose.
>The value for total fat is a key piece of fat information on the label Although there is a lot of publicity given to the pros and cons of the various types of fat, it is becoming clear that the effects of the various types of fat aren't as simple and predictable as once thought. For this reason, total fat remains the most useful fat information. When comparing brands choose the lower fat product.
Every day ways to cut back on fat
Every day ways to cut back on fat
The amount of fat you eat will vary from day to day. Some meals and some days will be higher in fat. That's okay. Even high fat meals can be in keeping with healthy eating as long as you balance higher fat meals or days with some lower fat meals or days.
It is the average intake of fat over the course of weeks and months that is important, not the fat content of every food and meal you eat.
Ways to Cut Fat
Scenario: You drink 1 glass of whole/homo milk a day.
Action: Switch to 1% milk and cut out 6g of fat.
Scenario: When you make a sandwich you butter or spread margarine lightly on the bread and use mayonnaise with the filling as well.
Action: Omit the butter on the sandwich and cut out 4g of fat (1 tsp. of butter/margarine). Use light mayonnaise, instead or regular mayonnaise and cut out an additional 6g of fat.
Scenario: You buy lean meat but you like a generous portion......about 6oz of cooked meat for dinner.
Action: Reduce the portion size to the recommended 3 oz and cut out about 9g of fat for beef, pork and lamb and 5g of fat for poultry.
Scenario: You only drink 2 cups of coffee a day but you like double cream in both.
Action: Switch to 2% milk and cut out about 6g of fat. Think about what this means if you drink more than 2 cups of coffee!
Scenario: Everyone at your house loves pizza and you order one in once a week.
Action: Choose a vegetarian pizza with single cheese instead of pizza with the "works" and extra cheese, and cut out 13g of fat for every 2 slices.
Scenario: You like a croissant sandwich for lunch.
Action: Choose almost any other bun and cut out at least 9g of fat!
10 Signs of a Fad Diet
10 Signs of a Fad Diet
Ten Signs of a Fad Diet
1.Promises a large or fast weight loss (more than one to two pounds per week)
2.Does not include suggestions to consult with your doctor or a registered dietitian
3.Encourages you to eliminate food groups (such as grains) or eat from a limited selection of foods
4.Offers rigid menus that don't consider your likes, dislikes and lifestyles
5.Neglects active living or lifestyle changes
6.Provides far fewer calories than what is needed for an energized, healthy lifestyle
7.Contradicts what most trusted health professionals say
8.Depends on special products, supplements or treatments
9.Has miraculous claims
10.Relies on testimonials and anecdotes rather than scientific evidence
Bottom Line
The traditional weight loss method emphasizing a well-balanced diet with a variety of foods including grains, fruits & vegetables, dairy and meat/fish, low in total fats, saturated fats and trans fats in addition to being physically active can result in long lasting weight loss and improved health. This doesn't sound too exciting, and let's face it - fad diets sure do know how to hook us, don't they? However, the traditional weight loss method stands the test of time for a simple reason: It works!
Ten Signs of a Fad Diet
1.Promises a large or fast weight loss (more than one to two pounds per week)
2.Does not include suggestions to consult with your doctor or a registered dietitian
3.Encourages you to eliminate food groups (such as grains) or eat from a limited selection of foods
4.Offers rigid menus that don't consider your likes, dislikes and lifestyles
5.Neglects active living or lifestyle changes
6.Provides far fewer calories than what is needed for an energized, healthy lifestyle
7.Contradicts what most trusted health professionals say
8.Depends on special products, supplements or treatments
9.Has miraculous claims
10.Relies on testimonials and anecdotes rather than scientific evidence
Bottom Line
The traditional weight loss method emphasizing a well-balanced diet with a variety of foods including grains, fruits & vegetables, dairy and meat/fish, low in total fats, saturated fats and trans fats in addition to being physically active can result in long lasting weight loss and improved health. This doesn't sound too exciting, and let's face it - fad diets sure do know how to hook us, don't they? However, the traditional weight loss method stands the test of time for a simple reason: It works!
A Look at Fat Substitutes
The war on fat in the past decades drove food manufacturers to replace fat in many food items. One way is to continue providing the creamy texture and quality of fat but not its caloric content by using fat substitutes.
Fat substitutes can be divided into 3 categories:
Sugar-based fat substitutes: e.g. dextrins, maltodextrins, modified food starches, cellulose and various gums.
They are the ancestors of fat substitutes, which entered the market in 1960s and are still the most widely used. They are able to replace fat's bulkiness and moistness, but are unable to replace fat's cooking qualities. While 1 gram of fat yields 9 kcal, these sugar-based substitutes only yield 1-4 kcal per gram.
Protein-based fat substitutes: Simpless by NutraSweet Company
They are extracted from whey protein concentrate of proteins from egg whites and milk. First appeared in the market in late 80s, protein-based substitutes yield 4 kcal per gram but are unable to withstand high heat.
Fat-based fat substitutes: Olestra
Olestra cannot be broken down by the body for absorption and therefore passes through the GI unaltered and provides no calories. It produces the mouthfeel of real fat and can withstand high heat.
Concerns have been raised on its possible side effects and its interaction with other nutrient absorption. As it cannot be digested, Olestra can cause abdominal cramps and diarrhea. On the other, Olestra inhibits fat-soluble vitamins (Vit A, D, E and K) and carotenoids. Manufacturers promised to fortify food products with the fat-soluble vitamins.
As limited studies have been conducted in children, teens and elderly on the effect of olestra, it is not recommended for consumption by these populations until more comprehensive researches have been performed.
The war on fat in the past decades drove food manufacturers to replace fat in many food items. One way is to continue providing the creamy texture and quality of fat but not its caloric content by using fat substitutes.
Fat substitutes can be divided into 3 categories:
Sugar-based fat substitutes: e.g. dextrins, maltodextrins, modified food starches, cellulose and various gums.
They are the ancestors of fat substitutes, which entered the market in 1960s and are still the most widely used. They are able to replace fat's bulkiness and moistness, but are unable to replace fat's cooking qualities. While 1 gram of fat yields 9 kcal, these sugar-based substitutes only yield 1-4 kcal per gram.
Protein-based fat substitutes: Simpless by NutraSweet Company
They are extracted from whey protein concentrate of proteins from egg whites and milk. First appeared in the market in late 80s, protein-based substitutes yield 4 kcal per gram but are unable to withstand high heat.
Fat-based fat substitutes: Olestra
Olestra cannot be broken down by the body for absorption and therefore passes through the GI unaltered and provides no calories. It produces the mouthfeel of real fat and can withstand high heat.
Concerns have been raised on its possible side effects and its interaction with other nutrient absorption. As it cannot be digested, Olestra can cause abdominal cramps and diarrhea. On the other, Olestra inhibits fat-soluble vitamins (Vit A, D, E and K) and carotenoids. Manufacturers promised to fortify food products with the fat-soluble vitamins.
As limited studies have been conducted in children, teens and elderly on the effect of olestra, it is not recommended for consumption by these populations until more comprehensive researches have been performed.
CLA Conjugated Linoleic Acid: a Fat Burner for Weight Loss?
CLA Conjugated Linoleic Acid: a Fat Burner for Weight Loss?
Conjugated Linoleic Acid (CLA) is a fatty acid found naturally in meat and dairy food. Conjugated Linoleic Acid supplements currently sold as a fat burner for weight loss is derived from sunflower oil. There is some evidence, although limited, that conjugated linoleic acid supplements can increase fat loss in overweight people. It is uncertain how Conjugated Linoleic Acid help lose body fat. One study found that CLA may help burn and lose fat by increasing energy expenditure.
There are very few clinical trials of Conjugated Linoleic Acid in overweight people. These studies showed that Conjugated Linoleic Acid supplements did result in fat loss, but not body weight loss . A Swedish study published in 2001 showed that of it helped burn fat by decreasing abdominal fat in overweight men. Another Dutch study published in July 2003 showed that Conjugated Linoleic Acid supplements help maintain lean muscle tissue after weight loss.
Conjugated Linoleic Acid Key message: Research on Conjugated Linoleic Acid weight loss supplements in human is still very limited. What we know is that the effect of fat loss is more convincing in animal studies than in human studies; some human trials did found that CLA can reduce body fat. Safety and toxicity levels have not yet established. In addition, side effects have not been well-documented. If you are taking Conjugated Linoleic Acid supplements, please make sure to talk to your doctor.
Conjugated Linoleic Acid (CLA) is a fatty acid found naturally in meat and dairy food. Conjugated Linoleic Acid supplements currently sold as a fat burner for weight loss is derived from sunflower oil. There is some evidence, although limited, that conjugated linoleic acid supplements can increase fat loss in overweight people. It is uncertain how Conjugated Linoleic Acid help lose body fat. One study found that CLA may help burn and lose fat by increasing energy expenditure.
There are very few clinical trials of Conjugated Linoleic Acid in overweight people. These studies showed that Conjugated Linoleic Acid supplements did result in fat loss, but not body weight loss . A Swedish study published in 2001 showed that of it helped burn fat by decreasing abdominal fat in overweight men. Another Dutch study published in July 2003 showed that Conjugated Linoleic Acid supplements help maintain lean muscle tissue after weight loss.
Conjugated Linoleic Acid Key message: Research on Conjugated Linoleic Acid weight loss supplements in human is still very limited. What we know is that the effect of fat loss is more convincing in animal studies than in human studies; some human trials did found that CLA can reduce body fat. Safety and toxicity levels have not yet established. In addition, side effects have not been well-documented. If you are taking Conjugated Linoleic Acid supplements, please make sure to talk to your doctor.
Which Sweeteners are Safe?
Which Sweeteners are Safe?
Epidemic obesity and diabetes encouraged the growth of the artificial sweetener industry. Growing number of people are trying to lose weight or keeping the weight off. Sweeteners can be found in almost all chewing gum, diet pop and drinks, "light" yogurt and some frozen ice cream. If the product is "sugar free", "no sugar added", "carb-smart", it is very likely added with sweeteners. Always check the labels.
Types of Sweeteners
Nutritive Sweeteners provide calories to the diet at about four calories per gram, similar to the normal carbohydrate we obtain from food. Examples of nutritive sweeteners include white and brown table sugars and molasses, honey and syrups. In addition, sugar alcohols derived from fruits or commercially made are also nutritive sweeteners. The most common sugar alcohols include: sorbitol, mannitol, xylitol and maltitol. All nutritive sweeteners provide calories to the body and may affect your blood glucose.
Nonnutritive sweeteners are the true "artificial" sweeteners. They do not provide calories and will not influence blood glucose. These include: saccharin, neotame, aspartame, sucralose, stevia and acesulfame potassium (Ace-K)
Which Sweeteners are safe?
The Center of Science in the Public Interest published a report on sweeteners in May 2004. Here is the summary:
Sweetener Brand Comments
Sucralose Splenda Safe
Neotame n/a Safe
Sugar Alcohols sorbitol, xylitol, mannitol, maltitol etc Safe but may cause bloating, gas or diarrhea in large quantity
Tagatose Naturlose Safe but may cause flatulence, bloating, nausea or diarrhea in large quantity
Aspartame Equal, NutraSweet, NatraTaste Probably Safe. Some people reported headaches. People with PKU should avoid aspartame
Acesulfame Potassium Sweet One, Sunnett, Acesulfame Potassium (Ace-K) Inadequately tested
Stevia Sweet Leaf, Honey Leaf Inadequately tested. Stevia is not allowed to be added in food; only sold as a supplement. Stevia is not approved in Canada.
Saccharin Sweet 'N Low Unsafe. Studies have shown that it may cause cancer in rats. Saccharin has been banned in Canada for 30 years.
Moderation is always the key. Moderate use of sweeteners can be part of the enjoyment of eating in a healthy diet. Always read the labels of the packaged food to find out which sweetener is present. Remember: A diet drink doesn't mean we can drink numerous bottles a day. If you are trying to lose weight, it is best to follow the Healthy Eating Guidelines and be physically active.
Epidemic obesity and diabetes encouraged the growth of the artificial sweetener industry. Growing number of people are trying to lose weight or keeping the weight off. Sweeteners can be found in almost all chewing gum, diet pop and drinks, "light" yogurt and some frozen ice cream. If the product is "sugar free", "no sugar added", "carb-smart", it is very likely added with sweeteners. Always check the labels.
Types of Sweeteners
Nutritive Sweeteners provide calories to the diet at about four calories per gram, similar to the normal carbohydrate we obtain from food. Examples of nutritive sweeteners include white and brown table sugars and molasses, honey and syrups. In addition, sugar alcohols derived from fruits or commercially made are also nutritive sweeteners. The most common sugar alcohols include: sorbitol, mannitol, xylitol and maltitol. All nutritive sweeteners provide calories to the body and may affect your blood glucose.
Nonnutritive sweeteners are the true "artificial" sweeteners. They do not provide calories and will not influence blood glucose. These include: saccharin, neotame, aspartame, sucralose, stevia and acesulfame potassium (Ace-K)
Which Sweeteners are safe?
The Center of Science in the Public Interest published a report on sweeteners in May 2004. Here is the summary:
Sweetener Brand Comments
Sucralose Splenda Safe
Neotame n/a Safe
Sugar Alcohols sorbitol, xylitol, mannitol, maltitol etc Safe but may cause bloating, gas or diarrhea in large quantity
Tagatose Naturlose Safe but may cause flatulence, bloating, nausea or diarrhea in large quantity
Aspartame Equal, NutraSweet, NatraTaste Probably Safe. Some people reported headaches. People with PKU should avoid aspartame
Acesulfame Potassium Sweet One, Sunnett, Acesulfame Potassium (Ace-K) Inadequately tested
Stevia Sweet Leaf, Honey Leaf Inadequately tested. Stevia is not allowed to be added in food; only sold as a supplement. Stevia is not approved in Canada.
Saccharin Sweet 'N Low Unsafe. Studies have shown that it may cause cancer in rats. Saccharin has been banned in Canada for 30 years.
Moderation is always the key. Moderate use of sweeteners can be part of the enjoyment of eating in a healthy diet. Always read the labels of the packaged food to find out which sweetener is present. Remember: A diet drink doesn't mean we can drink numerous bottles a day. If you are trying to lose weight, it is best to follow the Healthy Eating Guidelines and be physically active.
Low Carb Diets - do they work?
Low Carb Diets - do they work?
Fad diets come and go - the Low Carb diets have received a lot of attention in the past few years yet again - since it became unpopular in the 70s. With millions of book sales and aggressive marketing campaigns, many people turn to these Low Carb diets such as the Atkins diet and the Zone. Do we know if they are safe and effective?
Low Carb Diets - the theory behind
The key message these Low Carb Diets conveys is that carbohydrates promote insulin production, which in turn results in weight gain. Therefore by reducing carbohydrate intake, we will lose weight.
The truth is: by eating a Low Carb diet, you do not provide sufficient carbohydrates to your body for daily function. Therefore it will start burning the stored carbohydrates (glycogen) for energy. When your body starts burning glycogen, water is released. Therefore the drastic initial drop of weight at the beginning is only water you lose as a result of burning glycogen.
Some Low Carb diets are indeed high in fat!!! Some of these diets promise that you may eat as much meat, butter and cream as you want. There is no way for someone to eat that much fatty food and justify that it is healthy to do so!!!! Numerous well-proven scientific research showed that diets high in fat and saturated fat can increase the risk of heart disease.
In addition, some Low Carb diets such as the Atkins Diet lump all carbohydrate foods together and give it a bad name. For example, the Atkins diet limits carbohydrate intake to just 20g daily at the beginning (vs 130g recommended level by the National Academy of Sciences' Institute of Medicine). Most grains, fruits, beans, potatoes, rice, pastas, some vegetables are all excluded from this diet. Fruits and Vegetables especially, are rich in fiber as well as antioxidants such as Vitamin C, carotenoids, flavonoids, etc which are essential in the prevention of heart disease and cancer.
Why do people lose weight initially on a low-carb diet?
The truth is - in addition to losing water drastically at the beginning, these low-carb diets are often calorie-restricted!!! Followers only eat an average of 1000 - 1400 calories daily; compared to an average intake of 1800 - 2200 calories. To lose 1 lb a week, you only need to eat 500 fewer calories per day than you metabolize. Therefore, it doesn't matter if you eat a high or low carb diet, you will lose weight if you restrict your calories to less than you need. One easy way to lose 500 calories a day without restricting food? Physical exercise. Speak to your registered dietitian - they are able to calculate how much calories you minimally need per day. Read 10 Tips for Easy Weight Loss.
Low Carb Diets Key Message: Short term drastic weight loss is often not lasting. If you are following a low carb diet, try not to over-restrict the "healthy carb" such as beans, whole grains, whole fruits and vegetables.
Bottom Line - Low Carb Diets and Weight Loss: The traditional weight loss method emphasizing a well-balanced diet with a variety of foods including grains, fruits & vegetables, dairy and meat/fish, low in total fats, saturated fats and trans fats in addition to being physically active can result in long lasting weight loss and improved health. This doesn't sound too exciting but it works!
Low Carb Diets - any uses?: Yes! Studies and clinical practice showed that lower carb diet is important in diabetes management. In addition, a study published in the American Journal of Clinical Nutrition Aug 2004 found that despite the ineffectiveness of a low glycemic index diet on weight loss, it can reduce LDL cholesterol (the Bad cholesterol) by 10%.
Fad diets come and go - the Low Carb diets have received a lot of attention in the past few years yet again - since it became unpopular in the 70s. With millions of book sales and aggressive marketing campaigns, many people turn to these Low Carb diets such as the Atkins diet and the Zone. Do we know if they are safe and effective?
Low Carb Diets - the theory behind
The key message these Low Carb Diets conveys is that carbohydrates promote insulin production, which in turn results in weight gain. Therefore by reducing carbohydrate intake, we will lose weight.
The truth is: by eating a Low Carb diet, you do not provide sufficient carbohydrates to your body for daily function. Therefore it will start burning the stored carbohydrates (glycogen) for energy. When your body starts burning glycogen, water is released. Therefore the drastic initial drop of weight at the beginning is only water you lose as a result of burning glycogen.
Some Low Carb diets are indeed high in fat!!! Some of these diets promise that you may eat as much meat, butter and cream as you want. There is no way for someone to eat that much fatty food and justify that it is healthy to do so!!!! Numerous well-proven scientific research showed that diets high in fat and saturated fat can increase the risk of heart disease.
In addition, some Low Carb diets such as the Atkins Diet lump all carbohydrate foods together and give it a bad name. For example, the Atkins diet limits carbohydrate intake to just 20g daily at the beginning (vs 130g recommended level by the National Academy of Sciences' Institute of Medicine). Most grains, fruits, beans, potatoes, rice, pastas, some vegetables are all excluded from this diet. Fruits and Vegetables especially, are rich in fiber as well as antioxidants such as Vitamin C, carotenoids, flavonoids, etc which are essential in the prevention of heart disease and cancer.
Why do people lose weight initially on a low-carb diet?
The truth is - in addition to losing water drastically at the beginning, these low-carb diets are often calorie-restricted!!! Followers only eat an average of 1000 - 1400 calories daily; compared to an average intake of 1800 - 2200 calories. To lose 1 lb a week, you only need to eat 500 fewer calories per day than you metabolize. Therefore, it doesn't matter if you eat a high or low carb diet, you will lose weight if you restrict your calories to less than you need. One easy way to lose 500 calories a day without restricting food? Physical exercise. Speak to your registered dietitian - they are able to calculate how much calories you minimally need per day. Read 10 Tips for Easy Weight Loss.
Low Carb Diets Key Message: Short term drastic weight loss is often not lasting. If you are following a low carb diet, try not to over-restrict the "healthy carb" such as beans, whole grains, whole fruits and vegetables.
Bottom Line - Low Carb Diets and Weight Loss: The traditional weight loss method emphasizing a well-balanced diet with a variety of foods including grains, fruits & vegetables, dairy and meat/fish, low in total fats, saturated fats and trans fats in addition to being physically active can result in long lasting weight loss and improved health. This doesn't sound too exciting but it works!
Low Carb Diets - any uses?: Yes! Studies and clinical practice showed that lower carb diet is important in diabetes management. In addition, a study published in the American Journal of Clinical Nutrition Aug 2004 found that despite the ineffectiveness of a low glycemic index diet on weight loss, it can reduce LDL cholesterol (the Bad cholesterol) by 10%.
What are Empty Calories?
What are Empty Calories?
(HealthCastle.com) You may have read the term “empty calories,” or heard it used by nutritionists or even talk show hosts on TV. But what exactly are empty calories? Why are they so bad for you , and how can you avoid them?
Keep reading to discover where these sneaky calories may be hiding in your diet!
Empty Calories = High Calories but Low Nutrition
Contains Calories: Carbohydrates, Protein and Fat (collectively known as Macro-nutrients)
No Calories: All vitamins & minerals including antioxidants (collectively known as Micro-nutrients) as well as fiber
“Empty Calories” describes foods high in calories but low in nutritional values (also known as junk food!), lacking the health-promoting micro-nutrients listed above.
Examples of foods containing mostly Empty Calories
French fries, fried chicken, chips and all other deep-fried foods
A large order of fries from a fast food chain can contain up to 570 kcal with a whopping 30 g of total fat and 8 g of trans fat! Tons of calories from fat and very few micro-nutrients.
Candy, pop and other sweetened packaged foods
A can of pop contains about 130 kcal as well as additives and colorings. Again, lots of calories from sugar but no micro-nutrients.
Beer, wine and all other alcoholic beverages
A can of beer contains about 150 kcal from sugar and not much of anything else. In addition, calories from alcohol tend to be stored as fat in the abdomen (leading to a “beer belly”).
Refined grains such as crackers, cookies, white rice and white bread
Refined grains do provide some B vitamins, but that's it.
How to Avoid Empty Calories?
Avoid deep-fried foods. Instead of deep-frying, use other methods of cooking. For instance, have a baked potato with skin instead of fries, or a piece of baked skinless chicken breast instead of fried chicken.
Avoid sweetened drinks and canned drinks.
Try whole grains instead of refined grains. Whole grains are packed with beneficial fiber and antioxidants. For instance, have a slice of whole-wheat bread instead of white bread. Have a bowl of whole-grain breakfast cereals or unsweetened oatmeal instead of corn flakes.
Snack on fruits! Instead of prowling for a box of crackers in the mid afternoon, snack on fruits. Better yet, dip them in low-fat yogurt to get additional calcium and protein.
(HealthCastle.com) You may have read the term “empty calories,” or heard it used by nutritionists or even talk show hosts on TV. But what exactly are empty calories? Why are they so bad for you , and how can you avoid them?
Keep reading to discover where these sneaky calories may be hiding in your diet!
Empty Calories = High Calories but Low Nutrition
Contains Calories: Carbohydrates, Protein and Fat (collectively known as Macro-nutrients)
No Calories: All vitamins & minerals including antioxidants (collectively known as Micro-nutrients) as well as fiber
“Empty Calories” describes foods high in calories but low in nutritional values (also known as junk food!), lacking the health-promoting micro-nutrients listed above.
Examples of foods containing mostly Empty Calories
French fries, fried chicken, chips and all other deep-fried foods
A large order of fries from a fast food chain can contain up to 570 kcal with a whopping 30 g of total fat and 8 g of trans fat! Tons of calories from fat and very few micro-nutrients.
Candy, pop and other sweetened packaged foods
A can of pop contains about 130 kcal as well as additives and colorings. Again, lots of calories from sugar but no micro-nutrients.
Beer, wine and all other alcoholic beverages
A can of beer contains about 150 kcal from sugar and not much of anything else. In addition, calories from alcohol tend to be stored as fat in the abdomen (leading to a “beer belly”).
Refined grains such as crackers, cookies, white rice and white bread
Refined grains do provide some B vitamins, but that's it.
How to Avoid Empty Calories?
Avoid deep-fried foods. Instead of deep-frying, use other methods of cooking. For instance, have a baked potato with skin instead of fries, or a piece of baked skinless chicken breast instead of fried chicken.
Avoid sweetened drinks and canned drinks.
Try whole grains instead of refined grains. Whole grains are packed with beneficial fiber and antioxidants. For instance, have a slice of whole-wheat bread instead of white bread. Have a bowl of whole-grain breakfast cereals or unsweetened oatmeal instead of corn flakes.
Snack on fruits! Instead of prowling for a box of crackers in the mid afternoon, snack on fruits. Better yet, dip them in low-fat yogurt to get additional calcium and protein.
A High Carb Diet does not make you fat
A High Carb Diet does not make you fat
Another Study affirmed that a Low-Fat High-Carb diet does not cause Weight Gain
Researchers found women following a diet low in fat and high in fruits, vegetables and grains actually lost weight, not gained weight. Published in the Journal of American Medical Association in January 2006, the Women's Health Initiative Dietary Modification Trial followed close to 50,000 post-menopausal women for more than 7 years. Results showed that, in the first year, the women trained to eat a healthy low-fat diet lost about 5 pounds. After 7 1/2 years, they still maintained a modest weight loss compared to the women who did not receive education on healthy eating.
Many diet books blamed high-carb diets as the reason for the obesity epidemics. Healthcare professionals, for years, have been explaining to the public that it's not the carbs - it's actually the total calories that contributes to weight gain. This long-term randomized trial with a large population is a perfect study to prove these diet books wrong. Indeed, it is important to note about this study - these women actually lost weight despite the fact that they were not intending to lose weight at all. Weight loss results would be even more dramatic if they were trying to do so. As the author Dr. Howard noted, the results of this study demonstrated that "long-term recommendations to achieve a diet lower in total and saturated fat with increased consumption of fruits, vegetables, and whole grains, and without focus on weight loss, do not cause weight gain."
Carb 101: Carbohydrates are found in fruits and vegetables. Emphasize on choosing a variety of fruits and dark green leafy as well as bright-colored vegetables which are loaded with antioxidants and fiber. In addition, carbohydrates are also found in grain products. The American Dietary Guidelines recommend eating at least half the grains as whole grains - that's at least 3 servings of whole grains a day. For more information about whole grains, refer to our Whole Grains Guide.
To cut fat in your diet
remove skin and visible fats from meats
choose leaner cuts of meat such as skinless breast from poultry. For beef, choose eye of round, top round roast, top sirloin and flank; for pork, choose tenderloin and loin chops.
occasionally substitute meat products with fish and seafood (high in omega-3 fatty acids), soy products (high in heart-friendly soy protein) and nuts (high in omega-3 fatty acids and fiber)
use lower-fat versions if available of salad dressings, spreads, dairy products and cooking sauces etc
Another Study affirmed that a Low-Fat High-Carb diet does not cause Weight Gain
Researchers found women following a diet low in fat and high in fruits, vegetables and grains actually lost weight, not gained weight. Published in the Journal of American Medical Association in January 2006, the Women's Health Initiative Dietary Modification Trial followed close to 50,000 post-menopausal women for more than 7 years. Results showed that, in the first year, the women trained to eat a healthy low-fat diet lost about 5 pounds. After 7 1/2 years, they still maintained a modest weight loss compared to the women who did not receive education on healthy eating.
Many diet books blamed high-carb diets as the reason for the obesity epidemics. Healthcare professionals, for years, have been explaining to the public that it's not the carbs - it's actually the total calories that contributes to weight gain. This long-term randomized trial with a large population is a perfect study to prove these diet books wrong. Indeed, it is important to note about this study - these women actually lost weight despite the fact that they were not intending to lose weight at all. Weight loss results would be even more dramatic if they were trying to do so. As the author Dr. Howard noted, the results of this study demonstrated that "long-term recommendations to achieve a diet lower in total and saturated fat with increased consumption of fruits, vegetables, and whole grains, and without focus on weight loss, do not cause weight gain."
Carb 101: Carbohydrates are found in fruits and vegetables. Emphasize on choosing a variety of fruits and dark green leafy as well as bright-colored vegetables which are loaded with antioxidants and fiber. In addition, carbohydrates are also found in grain products. The American Dietary Guidelines recommend eating at least half the grains as whole grains - that's at least 3 servings of whole grains a day. For more information about whole grains, refer to our Whole Grains Guide.
To cut fat in your diet
remove skin and visible fats from meats
choose leaner cuts of meat such as skinless breast from poultry. For beef, choose eye of round, top round roast, top sirloin and flank; for pork, choose tenderloin and loin chops.
occasionally substitute meat products with fish and seafood (high in omega-3 fatty acids), soy products (high in heart-friendly soy protein) and nuts (high in omega-3 fatty acids and fiber)
use lower-fat versions if available of salad dressings, spreads, dairy products and cooking sauces etc
Sunday, October 14, 2007
Super foods for Weight Loss
Super foods for Weight Loss: Fruits and Vegetables
We're not suggesting you turn vegetarian, but simply up your intake of fruits & vegetables, legumes, whole grains, nuts and seeds. And, by doing this combined with other important diet strategies, you may lose weight naturally. Most plant foods are low-calorie, low-fat and very filling. And since they're fresh and whole, you won't be filling your body with processed ingredients.
It's important to consume a wide variety of colorful plant foods to reap the health benefits. That's because each contains different phytochemicals that work synergistically to combat disease. So the phytochemicals in the pink grapefruit you ate for breakfast, for instance, may fight disease more effectively when combined with the avocado in your salad at lunch.
Super Foods for Super Health
Plant foods are all-stars, because each contains unique phytochemicals that work together to fight disease. What's more, there are thousands of foods that have yet to be analyzed, so there's more good news to come.
Based on the latest research, the following foods contain phytochemicals that are proving to be terrific choices, says David Heber, M.D., Ph.D., director of the University of California, Los Angeles, Center for Human Nutrition and author of What Color Is Your Diet? (HarperCollins, 2001). So eat more of these:
Broccoli, cabbage and kale
The isothiocynanates in these cruciferous vegetables stimulate the liver to break down pesticides and other carcinogens. In people susceptible to colon cancer, these phytochemicals seem to reduce risk.
Carrots, mangos and winter squash
The alpha and beta carotenes in these orange vegetables and fruits play a role in cancer prevention, particularly of the lung, esophagus and stomach.
Citrus fruits, red apples and yams
The large family of compounds known as flavonoids found in these fruits and vegetables (as well as red wine) show promise as cancer fighters.
Garlic and onions
The onion family (including leeks, chives and scallions) is rich in allyl sulfides, which can help lower high blood pressure and show promise in protecting against cancers of the stomach and the digestive tract. Also read Benefits of Garlic in Heart Disease.
Pink grapefruit, red bell peppers and tomatoes
The phytochemical lycopene is actually more available after cooking, which makes tomato paste and ketchup the best sources of it. Lycopene shows promise in fighting lung and prostate cancers.
Red grapes, blueberries and strawberries
The anthocyanins that give these fruits their distinctive colors may help ward off heart disease by preventing clot formation. Anthocyanins also appear to inhibit tumor growth.
Spinach, collard greens and avocado
Lutein, which appears to reduce the risk of cardiovascular disease and stroke as well as guard against age-related macular degeneration (which leads to blindness), is also abundant in pumpkins.
We're not suggesting you turn vegetarian, but simply up your intake of fruits & vegetables, legumes, whole grains, nuts and seeds. And, by doing this combined with other important diet strategies, you may lose weight naturally. Most plant foods are low-calorie, low-fat and very filling. And since they're fresh and whole, you won't be filling your body with processed ingredients.
It's important to consume a wide variety of colorful plant foods to reap the health benefits. That's because each contains different phytochemicals that work synergistically to combat disease. So the phytochemicals in the pink grapefruit you ate for breakfast, for instance, may fight disease more effectively when combined with the avocado in your salad at lunch.
Super Foods for Super Health
Plant foods are all-stars, because each contains unique phytochemicals that work together to fight disease. What's more, there are thousands of foods that have yet to be analyzed, so there's more good news to come.
Based on the latest research, the following foods contain phytochemicals that are proving to be terrific choices, says David Heber, M.D., Ph.D., director of the University of California, Los Angeles, Center for Human Nutrition and author of What Color Is Your Diet? (HarperCollins, 2001). So eat more of these:
Broccoli, cabbage and kale
The isothiocynanates in these cruciferous vegetables stimulate the liver to break down pesticides and other carcinogens. In people susceptible to colon cancer, these phytochemicals seem to reduce risk.
Carrots, mangos and winter squash
The alpha and beta carotenes in these orange vegetables and fruits play a role in cancer prevention, particularly of the lung, esophagus and stomach.
Citrus fruits, red apples and yams
The large family of compounds known as flavonoids found in these fruits and vegetables (as well as red wine) show promise as cancer fighters.
Garlic and onions
The onion family (including leeks, chives and scallions) is rich in allyl sulfides, which can help lower high blood pressure and show promise in protecting against cancers of the stomach and the digestive tract. Also read Benefits of Garlic in Heart Disease.
Pink grapefruit, red bell peppers and tomatoes
The phytochemical lycopene is actually more available after cooking, which makes tomato paste and ketchup the best sources of it. Lycopene shows promise in fighting lung and prostate cancers.
Red grapes, blueberries and strawberries
The anthocyanins that give these fruits their distinctive colors may help ward off heart disease by preventing clot formation. Anthocyanins also appear to inhibit tumor growth.
Spinach, collard greens and avocado
Lutein, which appears to reduce the risk of cardiovascular disease and stroke as well as guard against age-related macular degeneration (which leads to blindness), is also abundant in pumpkins.
The Flat Ab Diet
The Flat Ab Diet
Weight Loss Nutrition Tips
Just can't get rid of your flabby belly, even though you do sit-ups and crunches until you're ready to drop? Assuming that you are already physically active and have a sensible diet with lots of fruits and vegetables and low in fat and your belly is still a bit bigger than you wish, read on. If you want to go from fat to fab abs, new research shows that what you eat is just as important as how - or even how much - you work out.
Ab Diet Tip 1. Eat more fiber.
Not eating enough fiber may be a major reason women are getting fatter and flabbier. To ditch the fat and show off firm, beautiful abs, you need to eat at least 25 grams of fiber daily, says leading fiber researcher David J.A. Jenkins, M.D., Ph.D., D.Sc., Professor of Nutrition at the University of Toronto, and a member of the National Academy of Sciences (NAS) Food and Nutrition Board. Fiber, which is the indigestible part of fruits, vegetables and whole-grain foods, helps you achieve flat abs.
How to add fiber to your diet comfortably? One cautionary note: It's important to add fiber slowly but consistently to prevent gas. "Make higher-fiber choices throughout the day; don't have all your fiber in one bunch," Jenkins says. "This is particularly important with viscous fiber - a type of soluble fiber found in beans, oats and barley that also has the benefit of lowering blood cholesterol," he says.
For best results, increase your fiber intake slowly over the course of one month and drink plenty of water to keep food moving through your system as quickly as possible.
Ab Diet Tip 2. Opt for a sensible amount of high-quality carbs.
For flatter abs, make carbs 45–- 65 percent (202 - 292) grams based on an 1,800-calorie diet) of your total daily calories. Balance is the key here, so don't go below 45 percent (202 grams), or above 65 percent (292 grams), which can lead to water retention, bloating and temporary weight gain that shows up in your middle.
When you eat carbs, they break down into glucose, which is stored as glycogen in the muscles and liver. When glycogen is stored, it carries with it three times its own weight as water, compared to no water at all for protein and fat, according to Peter Garlick, Ph.D., a professor at Stony Brook University in New York. If you eat an extremely high-carb diet, you may store excess water, experience bloating and gain temporary water weight. (This is why people who go on no- or very low-carb diets can initially lose weight so quickly. They're really just losing water.)
Focus on balanced eating. For best results, eat at least three to five 4-ounce servings of veggies (15 - 25 grams of carbs); two to four 4-ounce servings of fruit (30–60 grams of carbs) and about 1 cup (8 ounces cooked or 2 ounces dry, or 2 slices of bread) of whole grains per meal (90 grams per day).
Ab Diet Tip 3. Drink up!
Many women believe that drinking too much water will give them puffy abs, but just the opposite is true. "Even though we associate water with being bloated, drinking more water can help to flush sodium out of the body, and that reduces the bloat," said Jeff Hampl, Ph.D., R.D., nutrition researcher and assistant professor at Arizona State University.
Drink at least eight 8-ounce glasses of water per day. Beverages with little or no calories, caffeine or sodium, including herbal tea, are best. Avoid regular soft drinks and soups with lots of sodium. If you are eating plenty of water-rich foods such as fruits, vegetables and low-sodium soups, you can get half of your water requirements from foods, according to a 1998 NAS Food and Nutrition Board report.
Avoid carbonated drinks. Fizzy drinks, including soda pop and spritzers, increase bloating because the carbon dioxide trapped in the bubbles creates gas, which slows down stomach emptying.
Ab Diet Tip 4. Watch the sodium.
Sodium may have a bad rep, but it's essential for regulating body fluids and blood pressure as well as for nerve transmission, muscle function and absorption of important nutrients. But even a small amount of excess sodium causes bloating.
The American Heart Association recommends you consume no more than 2,400 milligrams of sodium daily — roughly 1 teaspoon of table salt. That's enough sodium to replenish your supply even if you work up a major sweat.
Choose fresh, natural foods over fast, commercial or packaged foods. Instead of ordering french fries (265 milligrams of sodium), have a baked potato (8 milligrams). Instead of a pickle (1,730 milligrams!), enjoy a fresh cucumber (6 milligrams). And beware of cured meats: Three ounces of ham packs in 1,009 milligrams of sodium, compared to just 48 milligrams for the same amount of roast pork. Soups are also notoriously high in sodium; some canned varieties contain more than 1,100 milligrams per cup. Read labels carefully and stick with low-sodium brands like Healthy Choice.
Ab Diet Tip 5. Eat light at night.
It never fails: You have a heavier-than-normal evening meal or snack, and when you weigh yourself the next morning, you're up by several pounds. But as depressing as it may seem at the moment, such a quick gain is always water weight; you simply cannot gain that much fat overnight.
In a study conducted by Callaway, people who skipped breakfast or lunch and ate their largest meal later in the day had lower metabolisms. So by eating light at night you'll receive a double benefit: You'll wake up with a flatter tummy, and you'll also have a better appetite for a fiber-rich breakfast, which sets you up for a day of healthful eating. Some tips to get you started:
Eat five times a day. Your body needs food every three to four hours, so instead of eating three large meals, try to schedule five smaller, more frequent meals throughout the day (breakfast-snack-lunch-snack-dinner). By staying full and energized, you'll avoid hunger pangs, maintain an even energy flow, make better, healthier food choices (no binging or craving) and enjoy the most efficient burning of calories.
Ab Diet Tip 6. Reduce stress.
Research shows that stress triggers the hormone cortisol to turn up your appetite and deposit fat around the organs in your abdomen. Pamela Peeke, M.D., M.P.H., author of Fight Fat After Forty (Penguin, 2000) calls this "toxic weight," because it's associated with heart disease, diabetes and cancer.
Weight Loss Nutrition Tips
Just can't get rid of your flabby belly, even though you do sit-ups and crunches until you're ready to drop? Assuming that you are already physically active and have a sensible diet with lots of fruits and vegetables and low in fat and your belly is still a bit bigger than you wish, read on. If you want to go from fat to fab abs, new research shows that what you eat is just as important as how - or even how much - you work out.
Ab Diet Tip 1. Eat more fiber.
Not eating enough fiber may be a major reason women are getting fatter and flabbier. To ditch the fat and show off firm, beautiful abs, you need to eat at least 25 grams of fiber daily, says leading fiber researcher David J.A. Jenkins, M.D., Ph.D., D.Sc., Professor of Nutrition at the University of Toronto, and a member of the National Academy of Sciences (NAS) Food and Nutrition Board. Fiber, which is the indigestible part of fruits, vegetables and whole-grain foods, helps you achieve flat abs.
How to add fiber to your diet comfortably? One cautionary note: It's important to add fiber slowly but consistently to prevent gas. "Make higher-fiber choices throughout the day; don't have all your fiber in one bunch," Jenkins says. "This is particularly important with viscous fiber - a type of soluble fiber found in beans, oats and barley that also has the benefit of lowering blood cholesterol," he says.
For best results, increase your fiber intake slowly over the course of one month and drink plenty of water to keep food moving through your system as quickly as possible.
Ab Diet Tip 2. Opt for a sensible amount of high-quality carbs.
For flatter abs, make carbs 45–- 65 percent (202 - 292) grams based on an 1,800-calorie diet) of your total daily calories. Balance is the key here, so don't go below 45 percent (202 grams), or above 65 percent (292 grams), which can lead to water retention, bloating and temporary weight gain that shows up in your middle.
When you eat carbs, they break down into glucose, which is stored as glycogen in the muscles and liver. When glycogen is stored, it carries with it three times its own weight as water, compared to no water at all for protein and fat, according to Peter Garlick, Ph.D., a professor at Stony Brook University in New York. If you eat an extremely high-carb diet, you may store excess water, experience bloating and gain temporary water weight. (This is why people who go on no- or very low-carb diets can initially lose weight so quickly. They're really just losing water.)
Focus on balanced eating. For best results, eat at least three to five 4-ounce servings of veggies (15 - 25 grams of carbs); two to four 4-ounce servings of fruit (30–60 grams of carbs) and about 1 cup (8 ounces cooked or 2 ounces dry, or 2 slices of bread) of whole grains per meal (90 grams per day).
Ab Diet Tip 3. Drink up!
Many women believe that drinking too much water will give them puffy abs, but just the opposite is true. "Even though we associate water with being bloated, drinking more water can help to flush sodium out of the body, and that reduces the bloat," said Jeff Hampl, Ph.D., R.D., nutrition researcher and assistant professor at Arizona State University.
Drink at least eight 8-ounce glasses of water per day. Beverages with little or no calories, caffeine or sodium, including herbal tea, are best. Avoid regular soft drinks and soups with lots of sodium. If you are eating plenty of water-rich foods such as fruits, vegetables and low-sodium soups, you can get half of your water requirements from foods, according to a 1998 NAS Food and Nutrition Board report.
Avoid carbonated drinks. Fizzy drinks, including soda pop and spritzers, increase bloating because the carbon dioxide trapped in the bubbles creates gas, which slows down stomach emptying.
Ab Diet Tip 4. Watch the sodium.
Sodium may have a bad rep, but it's essential for regulating body fluids and blood pressure as well as for nerve transmission, muscle function and absorption of important nutrients. But even a small amount of excess sodium causes bloating.
The American Heart Association recommends you consume no more than 2,400 milligrams of sodium daily — roughly 1 teaspoon of table salt. That's enough sodium to replenish your supply even if you work up a major sweat.
Choose fresh, natural foods over fast, commercial or packaged foods. Instead of ordering french fries (265 milligrams of sodium), have a baked potato (8 milligrams). Instead of a pickle (1,730 milligrams!), enjoy a fresh cucumber (6 milligrams). And beware of cured meats: Three ounces of ham packs in 1,009 milligrams of sodium, compared to just 48 milligrams for the same amount of roast pork. Soups are also notoriously high in sodium; some canned varieties contain more than 1,100 milligrams per cup. Read labels carefully and stick with low-sodium brands like Healthy Choice.
Ab Diet Tip 5. Eat light at night.
It never fails: You have a heavier-than-normal evening meal or snack, and when you weigh yourself the next morning, you're up by several pounds. But as depressing as it may seem at the moment, such a quick gain is always water weight; you simply cannot gain that much fat overnight.
In a study conducted by Callaway, people who skipped breakfast or lunch and ate their largest meal later in the day had lower metabolisms. So by eating light at night you'll receive a double benefit: You'll wake up with a flatter tummy, and you'll also have a better appetite for a fiber-rich breakfast, which sets you up for a day of healthful eating. Some tips to get you started:
Eat five times a day. Your body needs food every three to four hours, so instead of eating three large meals, try to schedule five smaller, more frequent meals throughout the day (breakfast-snack-lunch-snack-dinner). By staying full and energized, you'll avoid hunger pangs, maintain an even energy flow, make better, healthier food choices (no binging or craving) and enjoy the most efficient burning of calories.
Ab Diet Tip 6. Reduce stress.
Research shows that stress triggers the hormone cortisol to turn up your appetite and deposit fat around the organs in your abdomen. Pamela Peeke, M.D., M.P.H., author of Fight Fat After Forty (Penguin, 2000) calls this "toxic weight," because it's associated with heart disease, diabetes and cancer.
Powerful Benefits of Soy
Powerful Benefits of Soy
What has most interested scientists in recent years is the discovery of phytochemicals and the profound benefits of soy on human health. Benefits of soy include promoting heart health and healthy bones, preventing cancer and alleviating menopausal symptoms.
Soy beans contain high amounts of protein, including all essential amino acids (the only such vegetable source). Soy beans are also a rich source of calcium, iron, zinc, phosphorus, magnesium, B-vitamins, omega 3 fatty acids and fiber.
Benefits of Soy: Heart Health
The cholesterol lowering effect of soy milk and its role of heart disease was widely recognized in the mid 90s when the results of a meta-analysis of 38 clinical studies were published. The results demonstrated that a diet with significant soy protein reduces Total Cholesterol, LDL cholesterol (the "Bad" cholesterol) and Triglycerides.
The average consumption in these studies was 47 grams per day of soy protein, which is a considerable amount. One way to include this is to try a soy protein beverage or powder that may add 20 grams preserving. Soy protein was effective even in people who were already following the American Heart Association's 30 percent-fat diet. Soy protein appears to lower triglyceride levels while preserving HDL cholesterol.
Researchers Erdman & Potter in 1993 reported in the American Journal of Clinical Nutrition a 12 percent drop in cholesterol when 20 to 25 grams of soy protein and fiber were included in the diet. Soy beans contain soluble fiber, which is known to interfere with the absorption and metabolism of cholesterol.
As a result of these findings, in 1999, FDA authorized a health claim about the relationship between soy protein and Coronary Heart Disease (CHD) on labelling of foods containing soy protein.
A heart health claim can be found on qualified soy products.
Health Claim:
Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease. One serving of [name of produce] provides [amount]g of soy protein.
A few recent studies released in 2005 found that soy only had a modest effect on cholesterol levels. The American Heart Association no longer recommends soy for heart disease. FDA is currently reviewing its policy on soy health claim. So what should you do? Enjoy your soy foods like before. It may not lower cholesterol to an extent we originally thought, but it certainly does not harm our health!
Benefits of Soy: Healthy Bones
Many soy foods are naturally high in calcium (some fortified with calcium because it is a good source of a particular coagulating agent). In addition, soy also contains magnesium and boron, which are important co-factors of calcium for bone health.
Isoflavones in soy foods may inhibit the breakdown of bones. Daidzein, a type of isoflavone, is actually very similar to the drug ipriflavone, which is used throughout Europe and Asia to treat osteoporosis. One compelling study completed by Erdman in 1993 focused on post-menopausal women who consumed 40 grams of isolated soy protein daily for 6 months. Researchers found that these subjects significantly increased bone mineral density as compared to the controls.
Another study published in the Archives of Internal Medicine in September 2005 also found that intake of soy food was associated with a significantly lower risk of fracture, particularly among early post-menopausal women.
Benefits of Soy: Menopause
In Japan, where soy foods are commonly consumed daily, women are only one-third as likely to report menopausal symptoms as in the United States or Canada. In fact, there is no word in the Japanese language for "hot flashes".
Current studies showed that soy only helps some women alleviate menopausal symptoms. Indeed, soy is more effective in preventing than alleviating hot flashes. Despite these findings, the North American Menopause Society in 2000 recommended that 40 - 80mg of isoflavones daily may help relieve menopausal symptoms.
Benefits of Soy: Cancer
Among all cancers, data on soy and prostate cancer seems to be the most promising; many studies support its role in the prevention and possible treatment of prostate cancer.
While some studies showed soy offers a protective effect against breast cancer, a few studies showed the estrogen-like effects in isoflavones may be harmful for women with breast cancer. American Institute for Cancer Research stresses that data on soy and breast cancer are not conclusive, and more work is needed to be done before any dietary recommendations can be made.
What we know at this point is the phytoestrogens in soy foods are "anti-estrogens". In other words, they may block estrogen from reaching the receptors - therefore potentially protecting women from developing breast cancer. Studies found that pre-menopausal women may benefit from eating soy foods as their natural estrogen levels are high.
However, this may not be true to post-menopausal women. Studies found that soy could become "pro-estrogen" in women with low levels of natural estrogen. In other words, concentrated soy supplements may add estrogen to the body and hence increase breast cancer risk in post-menopausal women. Therefore, post-menopausal women should avoid taking concentrated soy supplements until more is known. Eating soy products, however, is not harmful.
Benefits of Soy - the Bottom Line:
Although it is still inconclusive that soy can prevent any diseases, many studies have shown promising results. Include soy products such as edamame, tofu, tempeh, soy milk etc in your diet and enjoy the possible health benefits they may bring.
With increasing public concerns regarding genetically modified foods, look for soy products which use non-genetically modified soy crops in their production.
Soy products Available:
Calcium-fortified soy milk
Tofu
Soy nuts
Edamame
Tempeh
Miso
Other products such as soy patties, soy cheese, soy yogurt and breakfast cereal
What has most interested scientists in recent years is the discovery of phytochemicals and the profound benefits of soy on human health. Benefits of soy include promoting heart health and healthy bones, preventing cancer and alleviating menopausal symptoms.
Soy beans contain high amounts of protein, including all essential amino acids (the only such vegetable source). Soy beans are also a rich source of calcium, iron, zinc, phosphorus, magnesium, B-vitamins, omega 3 fatty acids and fiber.
Benefits of Soy: Heart Health
The cholesterol lowering effect of soy milk and its role of heart disease was widely recognized in the mid 90s when the results of a meta-analysis of 38 clinical studies were published. The results demonstrated that a diet with significant soy protein reduces Total Cholesterol, LDL cholesterol (the "Bad" cholesterol) and Triglycerides.
The average consumption in these studies was 47 grams per day of soy protein, which is a considerable amount. One way to include this is to try a soy protein beverage or powder that may add 20 grams preserving. Soy protein was effective even in people who were already following the American Heart Association's 30 percent-fat diet. Soy protein appears to lower triglyceride levels while preserving HDL cholesterol.
Researchers Erdman & Potter in 1993 reported in the American Journal of Clinical Nutrition a 12 percent drop in cholesterol when 20 to 25 grams of soy protein and fiber were included in the diet. Soy beans contain soluble fiber, which is known to interfere with the absorption and metabolism of cholesterol.
As a result of these findings, in 1999, FDA authorized a health claim about the relationship between soy protein and Coronary Heart Disease (CHD) on labelling of foods containing soy protein.
A heart health claim can be found on qualified soy products.
Health Claim:
Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease. One serving of [name of produce] provides [amount]g of soy protein.
A few recent studies released in 2005 found that soy only had a modest effect on cholesterol levels. The American Heart Association no longer recommends soy for heart disease. FDA is currently reviewing its policy on soy health claim. So what should you do? Enjoy your soy foods like before. It may not lower cholesterol to an extent we originally thought, but it certainly does not harm our health!
Benefits of Soy: Healthy Bones
Many soy foods are naturally high in calcium (some fortified with calcium because it is a good source of a particular coagulating agent). In addition, soy also contains magnesium and boron, which are important co-factors of calcium for bone health.
Isoflavones in soy foods may inhibit the breakdown of bones. Daidzein, a type of isoflavone, is actually very similar to the drug ipriflavone, which is used throughout Europe and Asia to treat osteoporosis. One compelling study completed by Erdman in 1993 focused on post-menopausal women who consumed 40 grams of isolated soy protein daily for 6 months. Researchers found that these subjects significantly increased bone mineral density as compared to the controls.
Another study published in the Archives of Internal Medicine in September 2005 also found that intake of soy food was associated with a significantly lower risk of fracture, particularly among early post-menopausal women.
Benefits of Soy: Menopause
In Japan, where soy foods are commonly consumed daily, women are only one-third as likely to report menopausal symptoms as in the United States or Canada. In fact, there is no word in the Japanese language for "hot flashes".
Current studies showed that soy only helps some women alleviate menopausal symptoms. Indeed, soy is more effective in preventing than alleviating hot flashes. Despite these findings, the North American Menopause Society in 2000 recommended that 40 - 80mg of isoflavones daily may help relieve menopausal symptoms.
Benefits of Soy: Cancer
Among all cancers, data on soy and prostate cancer seems to be the most promising; many studies support its role in the prevention and possible treatment of prostate cancer.
While some studies showed soy offers a protective effect against breast cancer, a few studies showed the estrogen-like effects in isoflavones may be harmful for women with breast cancer. American Institute for Cancer Research stresses that data on soy and breast cancer are not conclusive, and more work is needed to be done before any dietary recommendations can be made.
What we know at this point is the phytoestrogens in soy foods are "anti-estrogens". In other words, they may block estrogen from reaching the receptors - therefore potentially protecting women from developing breast cancer. Studies found that pre-menopausal women may benefit from eating soy foods as their natural estrogen levels are high.
However, this may not be true to post-menopausal women. Studies found that soy could become "pro-estrogen" in women with low levels of natural estrogen. In other words, concentrated soy supplements may add estrogen to the body and hence increase breast cancer risk in post-menopausal women. Therefore, post-menopausal women should avoid taking concentrated soy supplements until more is known. Eating soy products, however, is not harmful.
Benefits of Soy - the Bottom Line:
Although it is still inconclusive that soy can prevent any diseases, many studies have shown promising results. Include soy products such as edamame, tofu, tempeh, soy milk etc in your diet and enjoy the possible health benefits they may bring.
With increasing public concerns regarding genetically modified foods, look for soy products which use non-genetically modified soy crops in their production.
Soy products Available:
Calcium-fortified soy milk
Tofu
Soy nuts
Edamame
Tempeh
Miso
Other products such as soy patties, soy cheese, soy yogurt and breakfast cereal
WEIGHT LOSS TIPS
Tip 1: Find out how many calories you need
BMR (Basal Metabolic Rate)
BMR [kcal]
Body Weight [lb] x 15 + (moderate activity [mins/day] x 3.5)
Since you wish to lose weight, your target = BMR - 500 kcal
For instance, you weigh 140 lb and you perform 20 mins of moderate activity every day. BMR of this example = (140 x 15) + (20 x 3.5) = 2100 + 70 = 2170 kcal. BMR minus 500kcal; it would be 2170 - 500 = 1670 kcal. Therefore 1670 kcal is the target in this example to losing 1 lb per week.
Tip 2:
Eat at least 5 servings of fruits and vegetables per day
Fruits and vegetables are packed with beneficial fibers, vitamins and antioxidants. They fill up your stomach fast so you feel full earlier. They are also low in calories and helps to keep your calorie count low.
Top 5 Healthiest Foods - picked by Dietitians
Salmon : Salmon is favorite food to substitute meats. It is a good source of protein and omega 3 fatty acids - which has been shown to decrease LDL cholesterol and raise HDL cholesterol. In 2002, the American Heart Association recommended eating at least 2 servings of fish a week, particularly fatty fish such as salmon. With increasing public concerns over farmed salmon, choose wild salmon. Most canned salmon are wild.
Can eating Salmon help lower your blood cholesterol?
High cholesterol! This term seems to be highly used when dealing with today's health topics! It is the yellowish material in your arteries which narrows the blood vessels. But they are not all bad for you. You can lower the bad type of cholesterol (LDL - low density lipoprotein) and increase the good type of cholesterol (HDL - high density lipoprotein) by altering your diet. LDL is responsible for clogging your blood vessels and HDL helps to "exile" the LDL to the liver where LDL is "destroyed". Hence it is beneficial to have higher level of HDL and less LDL in your blood.
Salmon Oil
Omega-3 fatty acids found in salmon is an excellent source to boost up HDL in your blood stream. Omega-3 fatty acid is, indeed, a type of polyunsaturated fatty acids which can only be supplied by food sources. A study chaired by Gary J. Nelson, Ph.D., of the U.S. Dept of Agriculture's Western Human Nutrition Research Center in San Francisco, showed that HDL increased by 10% by just eating 20 days of a high salmon diet!
Moderation is the key. Include salmon (or other fish with high omega-3 content such us sardines and tuna) to your meals occasionally and enjoy its health benefits.
Salmon oil supplements are available on the market. Check with your doctor before consuming these pills as a single pill is more concentrated in Omega 3 fatty acids than 1 serving of salmon.
Caution: Do not take salmon oil supplements if you are taking a blood thinner drug as salmon oil supplements may further thin your blood.
Soy : Soy products are great substitutes for animal products. I love cooking tofu with various tasty Asian sauces and also enjoy drinking soy milk. Soy beans contain high amounts of protein which comprise of all essential amino acids (the only such vegetable source to do so). Soy beans are also a rich source of calcium, iron, zinc, phosphorus, magnesium, B vitamins, omega 3 fatty acids and fiber. Numerous scientific studies demonstrated that a diet containing significant soy protein may benefit heart health. In addition, more and more studies are being published suggesting other health benefits of soy such as the prevention of prostate & breast cancer as well as osteoporosis.
Greens : Green vegetables such as kale, chard, collard greens, bok choy, broccoli, asparagus, green beans, etc... are packed with vitamins A and C, iron, calcium and phytonutrients. They are very filling, high in fiber and low in calories. Personally, I like eating them cooked so I usually stir fry them in a non-stick pan, but it is absolutely fine to eat them raw as well so go ahead and toss them into your salad and reap the nutritional benefits!
Berries : Berries by far are my favorite fruits! They are loaded with Vitamin C, folate, fiber and phytonutrients. Indeed, fresh berries are some of the most powerful disease-fighting foods available as they top the ORAC score chart (a method of measuring antioxidant activity). Berries are easy to prepare - just wash and rinse - no need to peel at all! In addition, you may serve berries (fresh or baked) as part of a dessert dish.
Whole Grains:Whole grains have some valuable antioxidants not found in fruits and vegetables. They also contain B vitamins, vitamin E, magnesium, iron and fiber. The new 2005 Dietary Guidelines for Americans recommend that all adults eat half their grains as whole grains - that's 3 to 5 servings of whole grains a day. To include more servings of whole grains in your diet, use whole-wheat flour in your recipes instead of white flour. Look for the word "whole" when purchasing packaged foods such as cereals, biscuits, pasta and breads. In addition, try adding wild rice, brown rice, quinoa or barley in your soup to increase whole grain intake.
Tip 3: Watch for Portion Size
One serving of pasta means 1/2 cup of cooked pasta. However, most restaurants serve a pasta dish with 4 servings of pasta!!! You do not need to finish and clean off the plate every time. You can simply ask to take home the leftover.
Tip 4: Do not Skip Meals
Eating small frequent meals help to balance your calorie intake throughout the day and also keeps your blood sugar level balanced. Instead of eating 3 big meals, try to eat 5 - 6 smaller meals throughout the day.
4 Breakfast items you should Avoid:
Breakfast is the most important meal of the day. Not only does breakfast give you the fuel to break the fast you have undergone during a good night's sleep. Breakfast also helps you concentrate better throughout the day and helps maintain your weight. For most people, breakfast is the only meal to include some vital nutrients such as calcium from milk as well as fiber and antioxidants from whole grains. Therefore, it is wise to choose healthy breakfast items to start your day and avoid breakfast items that have no nutritional value.
4 Breakfast items to avoid
Carrot Cake MuffinPerhaps the word "carrot" make it sound like a healthy breakfast item, but most commercial carrot cake muffins are high in fat and calories. One serving of this favorite breakfast muffin from a coffee chain store contains a whopping 680 kilocalories and 40 grams of fat! Indeed, most muffins and scones are high in fat. Scones, in particular, usually contain trans fat as well.
DoughnutsDoughnuts are fried breakfast foods. If you do not eat french fries for breakfast, why would you eat fried doughnuts? One piece of glazed doughnut from a doughnut chain store contains 200 kcal of empty calories with precious few nutrients. What is worse is that it contains four grams of trans fat per serving. That is already two times more than the recommended amount of trans fat a day. Doughnuts with fillings contain even higher amounts of calories and trans fat, so stay away from this breakfast treat!
Frozen WafflesSimilar to doughnuts, frozen waffles are another example of empty calories when it comes to breakfast foods. Most store-bought frozen waffles are basically refined grain combined with refined sugar and trans fat, lacking health-promoting vitamins, minerals and fiber. Most people add syrup and margarine on their breakfast waffles, hence adding even more calories and fat. Not a smart choice to start your day!
McDonald's Deluxe BreakfastWith such breakfast items as scrambled eggs, hash browns, sausages, pancakes and dressing and syrup, this deluxe breakfast contains a shocking 1,120 kcal and 61 grams of fat! With that much fat, it is like swallowing 13 teaspoons of vegetable oil in one setting! What is more shockingis that this breakfast item at McDonald's contains 11 g of trans fat, that is is 5 times more than the daily recommended amount of trans fat!
The recommended daily intake for dairy is three servings a day and whole grains is at least three servings daily. If you do not normally eat these foods for lunch or dinner, it is easier to include these items in breakfast. Hence, choose whole grains such as whole wheat bread, whole grain cereals or oatmeal if possible. In addition, include a serving of dairy such as low-fat milk or low-fat yogurt, which is rich in protein, calcium and potassium. In general, try including at least three food groups in your breakfast so that you do not need to prowl for a mid-morning snack.
Tip 5: Go for wholesome fresh foods
If possible, purchase fresh foods and avoid package (processed) and convenient foods such as fast food. Packaged and convenient foods are often higher in sodium and fat content. Many people we spoke to are amazed that they can easily lose weight by packing a home-cooked lunch to work instead of eating out.
Tip 6: Don't be overly-restrictive
Everyone has his or her favorite treats. Simply allow yourself a little indulgence, but watch out for the frequency and the quantity. Having a small treat once in a while can be rewarding to your weight loss experience. Cutting too much of your favorite treats usually lead to an early relapse.
Tip 7: Understand Food Claims and Labels
A product labelled with a fat-free claim does not mean that it is low in calories. Similarly a product labelled as low-sugar or low-carb does not mean it is low in fat or calories. Always read the nutrition label on the packaging.
Tip 8: Watch for the sugary drinks
Juices, pop, cream & sugar in your coffee or tea all add up. Opt for drinking at least 8 glasses of water a day. In addition to providing hydration to your body, it will also help you feel full.
5 Myths about Drinks
Top 5 Myths about Drinks - debunked by Dietitians
1.
Diet Pop is healthier than Regular PopOne can of regular pop contains about 135 kilocalories whereas a can of diet pop contains less than 10 kilocalories; some even contain zero kilocalories. Therefore, it is true that diet pop contains fewer calories. However, it is rather difficult to agree that diet pop is "healthier" as there is really nothing healthy about artificially colored and flavored water.
2.
It is less fattening to drink juice than milkMany people are surprised to learn that a glass of juice contains more calories than a glass of one percent milk. Even two percent milk has only 10 kilocalories more than a glass of fruit juice, which has 120 kilocalories! While juice contains mostly sugar and some vitamins, milk has more nutrients such as protein, calcium, potassium and Vitamin D.
3.
All bottled waters such as sparkling water, tonic water, flavored water, and mineral water are WATERYes, plain bottled water is water and is calorie-free. Some flavored waters are made with water and real juice. However, many flavored waters are flavored with artificial sweeteners and contain little juice. Tonic water, for instance, has 125 kilocalories per serving. Hence, always read the label and check the ingredient list. If you drink bottled water instead of tap water regularly, make sure it contains fluoride.
4.
Drinking wine instead of beer won't make a beer-bellyIt is a common misconception that wine contains fewer calories than beer. It is simply not true. One glass of wine (five ounces) contains about 130 kilocalories whereas one bottle of beer (12 ounces) has about 150 kilocalories. Therefore, wine contains more calories on a per-ounce basis. As a general rule, the sweeter the wine, the more sugar and calories it contains. By the same token for hard liquor; the higher the proof, the higher the calories.Remember this next time when you are contemplating a second helping of alcohol: calories from alcohol tend to be stored as fat in the abdomen. So, if you drink alcohol on a regular basis (regardless of the kinds of alcohol), watch out for the beer-belly!
5.
Coffee is the main source of caffeineFriends have often told me that they quit drinking coffee for the sake of their hearts. Little did they know that the can of pop in their hands has caffeine, too! Caffeine is widely found in tea and canned drinks. Some drinks, such as Jolt and Red Bull, contain as much caffeine as coffee! In general, there is no harm to your health if you drink coffee in small to moderate amounts. However, it is advised that people with high blood pressure and pregnant women limit their caffeine consumption.
The Bottom Line
By substituting a can of pop or juice with a bottle of water every day, you may lose as many as 15 pounds per year. In addition, walking the stairs for 15 minutes every day, for instance, can help burn about 100 calories. It is that easy!
Remember, you always have a choice. When purchasing a bottle or canned drink, make it a habit to check the Nutrition Facts. Try bringing your own drink to work instead of choosing one from a vending machine with limited choice. This will not only save your wallet but also your waistline.
Tip 9: Keep a food journal
Keeping a food journal helps you pin point your eating pattern and will enable you to easily modify it. If possible, have your Registered Dietitian review your journal.
Tip 10: Exercise, period
Most authorities recommend 30 - 60 minutes of physical activity a day to stay healthy. Also try adding weight-bearing exercises at least 2 times a week. This will help burn some of the unwanted calories.
BMR (Basal Metabolic Rate)
BMR [kcal]
Body Weight [lb] x 15 + (moderate activity [mins/day] x 3.5)
Since you wish to lose weight, your target = BMR - 500 kcal
For instance, you weigh 140 lb and you perform 20 mins of moderate activity every day. BMR of this example = (140 x 15) + (20 x 3.5) = 2100 + 70 = 2170 kcal. BMR minus 500kcal; it would be 2170 - 500 = 1670 kcal. Therefore 1670 kcal is the target in this example to losing 1 lb per week.
Tip 2:
Eat at least 5 servings of fruits and vegetables per day
Fruits and vegetables are packed with beneficial fibers, vitamins and antioxidants. They fill up your stomach fast so you feel full earlier. They are also low in calories and helps to keep your calorie count low.
Top 5 Healthiest Foods - picked by Dietitians
Salmon : Salmon is favorite food to substitute meats. It is a good source of protein and omega 3 fatty acids - which has been shown to decrease LDL cholesterol and raise HDL cholesterol. In 2002, the American Heart Association recommended eating at least 2 servings of fish a week, particularly fatty fish such as salmon. With increasing public concerns over farmed salmon, choose wild salmon. Most canned salmon are wild.
Can eating Salmon help lower your blood cholesterol?
High cholesterol! This term seems to be highly used when dealing with today's health topics! It is the yellowish material in your arteries which narrows the blood vessels. But they are not all bad for you. You can lower the bad type of cholesterol (LDL - low density lipoprotein) and increase the good type of cholesterol (HDL - high density lipoprotein) by altering your diet. LDL is responsible for clogging your blood vessels and HDL helps to "exile" the LDL to the liver where LDL is "destroyed". Hence it is beneficial to have higher level of HDL and less LDL in your blood.
Salmon Oil
Omega-3 fatty acids found in salmon is an excellent source to boost up HDL in your blood stream. Omega-3 fatty acid is, indeed, a type of polyunsaturated fatty acids which can only be supplied by food sources. A study chaired by Gary J. Nelson, Ph.D., of the U.S. Dept of Agriculture's Western Human Nutrition Research Center in San Francisco, showed that HDL increased by 10% by just eating 20 days of a high salmon diet!
Moderation is the key. Include salmon (or other fish with high omega-3 content such us sardines and tuna) to your meals occasionally and enjoy its health benefits.
Salmon oil supplements are available on the market. Check with your doctor before consuming these pills as a single pill is more concentrated in Omega 3 fatty acids than 1 serving of salmon.
Caution: Do not take salmon oil supplements if you are taking a blood thinner drug as salmon oil supplements may further thin your blood.
Soy : Soy products are great substitutes for animal products. I love cooking tofu with various tasty Asian sauces and also enjoy drinking soy milk. Soy beans contain high amounts of protein which comprise of all essential amino acids (the only such vegetable source to do so). Soy beans are also a rich source of calcium, iron, zinc, phosphorus, magnesium, B vitamins, omega 3 fatty acids and fiber. Numerous scientific studies demonstrated that a diet containing significant soy protein may benefit heart health. In addition, more and more studies are being published suggesting other health benefits of soy such as the prevention of prostate & breast cancer as well as osteoporosis.
Greens : Green vegetables such as kale, chard, collard greens, bok choy, broccoli, asparagus, green beans, etc... are packed with vitamins A and C, iron, calcium and phytonutrients. They are very filling, high in fiber and low in calories. Personally, I like eating them cooked so I usually stir fry them in a non-stick pan, but it is absolutely fine to eat them raw as well so go ahead and toss them into your salad and reap the nutritional benefits!
Berries : Berries by far are my favorite fruits! They are loaded with Vitamin C, folate, fiber and phytonutrients. Indeed, fresh berries are some of the most powerful disease-fighting foods available as they top the ORAC score chart (a method of measuring antioxidant activity). Berries are easy to prepare - just wash and rinse - no need to peel at all! In addition, you may serve berries (fresh or baked) as part of a dessert dish.
Whole Grains:Whole grains have some valuable antioxidants not found in fruits and vegetables. They also contain B vitamins, vitamin E, magnesium, iron and fiber. The new 2005 Dietary Guidelines for Americans recommend that all adults eat half their grains as whole grains - that's 3 to 5 servings of whole grains a day. To include more servings of whole grains in your diet, use whole-wheat flour in your recipes instead of white flour. Look for the word "whole" when purchasing packaged foods such as cereals, biscuits, pasta and breads. In addition, try adding wild rice, brown rice, quinoa or barley in your soup to increase whole grain intake.
Tip 3: Watch for Portion Size
One serving of pasta means 1/2 cup of cooked pasta. However, most restaurants serve a pasta dish with 4 servings of pasta!!! You do not need to finish and clean off the plate every time. You can simply ask to take home the leftover.
Tip 4: Do not Skip Meals
Eating small frequent meals help to balance your calorie intake throughout the day and also keeps your blood sugar level balanced. Instead of eating 3 big meals, try to eat 5 - 6 smaller meals throughout the day.
4 Breakfast items you should Avoid:
Breakfast is the most important meal of the day. Not only does breakfast give you the fuel to break the fast you have undergone during a good night's sleep. Breakfast also helps you concentrate better throughout the day and helps maintain your weight. For most people, breakfast is the only meal to include some vital nutrients such as calcium from milk as well as fiber and antioxidants from whole grains. Therefore, it is wise to choose healthy breakfast items to start your day and avoid breakfast items that have no nutritional value.
4 Breakfast items to avoid
Carrot Cake MuffinPerhaps the word "carrot" make it sound like a healthy breakfast item, but most commercial carrot cake muffins are high in fat and calories. One serving of this favorite breakfast muffin from a coffee chain store contains a whopping 680 kilocalories and 40 grams of fat! Indeed, most muffins and scones are high in fat. Scones, in particular, usually contain trans fat as well.
DoughnutsDoughnuts are fried breakfast foods. If you do not eat french fries for breakfast, why would you eat fried doughnuts? One piece of glazed doughnut from a doughnut chain store contains 200 kcal of empty calories with precious few nutrients. What is worse is that it contains four grams of trans fat per serving. That is already two times more than the recommended amount of trans fat a day. Doughnuts with fillings contain even higher amounts of calories and trans fat, so stay away from this breakfast treat!
Frozen WafflesSimilar to doughnuts, frozen waffles are another example of empty calories when it comes to breakfast foods. Most store-bought frozen waffles are basically refined grain combined with refined sugar and trans fat, lacking health-promoting vitamins, minerals and fiber. Most people add syrup and margarine on their breakfast waffles, hence adding even more calories and fat. Not a smart choice to start your day!
McDonald's Deluxe BreakfastWith such breakfast items as scrambled eggs, hash browns, sausages, pancakes and dressing and syrup, this deluxe breakfast contains a shocking 1,120 kcal and 61 grams of fat! With that much fat, it is like swallowing 13 teaspoons of vegetable oil in one setting! What is more shockingis that this breakfast item at McDonald's contains 11 g of trans fat, that is is 5 times more than the daily recommended amount of trans fat!
The recommended daily intake for dairy is three servings a day and whole grains is at least three servings daily. If you do not normally eat these foods for lunch or dinner, it is easier to include these items in breakfast. Hence, choose whole grains such as whole wheat bread, whole grain cereals or oatmeal if possible. In addition, include a serving of dairy such as low-fat milk or low-fat yogurt, which is rich in protein, calcium and potassium. In general, try including at least three food groups in your breakfast so that you do not need to prowl for a mid-morning snack.
Tip 5: Go for wholesome fresh foods
If possible, purchase fresh foods and avoid package (processed) and convenient foods such as fast food. Packaged and convenient foods are often higher in sodium and fat content. Many people we spoke to are amazed that they can easily lose weight by packing a home-cooked lunch to work instead of eating out.
Tip 6: Don't be overly-restrictive
Everyone has his or her favorite treats. Simply allow yourself a little indulgence, but watch out for the frequency and the quantity. Having a small treat once in a while can be rewarding to your weight loss experience. Cutting too much of your favorite treats usually lead to an early relapse.
Tip 7: Understand Food Claims and Labels
A product labelled with a fat-free claim does not mean that it is low in calories. Similarly a product labelled as low-sugar or low-carb does not mean it is low in fat or calories. Always read the nutrition label on the packaging.
Tip 8: Watch for the sugary drinks
Juices, pop, cream & sugar in your coffee or tea all add up. Opt for drinking at least 8 glasses of water a day. In addition to providing hydration to your body, it will also help you feel full.
5 Myths about Drinks
Top 5 Myths about Drinks - debunked by Dietitians
1.
Diet Pop is healthier than Regular PopOne can of regular pop contains about 135 kilocalories whereas a can of diet pop contains less than 10 kilocalories; some even contain zero kilocalories. Therefore, it is true that diet pop contains fewer calories. However, it is rather difficult to agree that diet pop is "healthier" as there is really nothing healthy about artificially colored and flavored water.
2.
It is less fattening to drink juice than milkMany people are surprised to learn that a glass of juice contains more calories than a glass of one percent milk. Even two percent milk has only 10 kilocalories more than a glass of fruit juice, which has 120 kilocalories! While juice contains mostly sugar and some vitamins, milk has more nutrients such as protein, calcium, potassium and Vitamin D.
3.
All bottled waters such as sparkling water, tonic water, flavored water, and mineral water are WATERYes, plain bottled water is water and is calorie-free. Some flavored waters are made with water and real juice. However, many flavored waters are flavored with artificial sweeteners and contain little juice. Tonic water, for instance, has 125 kilocalories per serving. Hence, always read the label and check the ingredient list. If you drink bottled water instead of tap water regularly, make sure it contains fluoride.
4.
Drinking wine instead of beer won't make a beer-bellyIt is a common misconception that wine contains fewer calories than beer. It is simply not true. One glass of wine (five ounces) contains about 130 kilocalories whereas one bottle of beer (12 ounces) has about 150 kilocalories. Therefore, wine contains more calories on a per-ounce basis. As a general rule, the sweeter the wine, the more sugar and calories it contains. By the same token for hard liquor; the higher the proof, the higher the calories.Remember this next time when you are contemplating a second helping of alcohol: calories from alcohol tend to be stored as fat in the abdomen. So, if you drink alcohol on a regular basis (regardless of the kinds of alcohol), watch out for the beer-belly!
5.
Coffee is the main source of caffeineFriends have often told me that they quit drinking coffee for the sake of their hearts. Little did they know that the can of pop in their hands has caffeine, too! Caffeine is widely found in tea and canned drinks. Some drinks, such as Jolt and Red Bull, contain as much caffeine as coffee! In general, there is no harm to your health if you drink coffee in small to moderate amounts. However, it is advised that people with high blood pressure and pregnant women limit their caffeine consumption.
The Bottom Line
By substituting a can of pop or juice with a bottle of water every day, you may lose as many as 15 pounds per year. In addition, walking the stairs for 15 minutes every day, for instance, can help burn about 100 calories. It is that easy!
Remember, you always have a choice. When purchasing a bottle or canned drink, make it a habit to check the Nutrition Facts. Try bringing your own drink to work instead of choosing one from a vending machine with limited choice. This will not only save your wallet but also your waistline.
Tip 9: Keep a food journal
Keeping a food journal helps you pin point your eating pattern and will enable you to easily modify it. If possible, have your Registered Dietitian review your journal.
Tip 10: Exercise, period
Most authorities recommend 30 - 60 minutes of physical activity a day to stay healthy. Also try adding weight-bearing exercises at least 2 times a week. This will help burn some of the unwanted calories.
Oracle Architecture 5
Oracle8 New Features
Oracle8 has introduced many new features, and I would like to focus on a few key features for the Oracle8 DBA:
* Partitioned objects
* Improved parallelism
* New index types
* Enhanced recovery features
Partitioned Objects
Partitioned objects allow Oracle objects, such as tables and indexes, to be broken into smaller, more manageable pieces. Partitioning these objects allows many operations that could normally be performed on only a table or an index to be divided into operations on a partition. By dividing these operations, you can often increase the parallelism of those operations, thus improving performance and minimizing system downtime.
Partitions are enabled via the PARTITION BY RANGE parameter of the CREATE TABLE statement. In this manner, ranges of data are assigned to each individual partition like so: CREATE TABLE emp (name CHAR(30),address CHAR(40),region INTEGER)PARTITION BY RANGE ( region)(PARTITION VALUES LESS THAN (10) TABLESPACE tbl0,PARTITION VALUES LESS THAN (20) TABLESPACE tbl1,PARTITION VALUES LESS THAN (30) TABLESPACE tbl2);
Table partitioning
Partitioning is recommended for large tables because it makes them much more manageable. Oracle does not currently support partitioning of clusters. By partitioning a table, you can break that large table into several much smaller pieces. A partitioned table can take advantage of some of the following features:
* Partitioned DML
* Exporting/importing by partition
* Range partitioning
* Local and global indexing
* Parallel loading by partition
Partitioned DML
Parallel INSERT, DELETE, and UPDATE operations can occur on a partition basis. Using partitions allows these operations to be conducted either globally or locally within a partition.
Exporting/Importing by Partition
Partitioning allows operations such as exports and imports to be performed on a partition basis. This can reduce the time required by some maintenance operations, such as reorganization of data or reclustering. This also allows you to change the physical layout of your database on a partition basis. If you limit the scope of export and import operations, they can benefit from a large degree of parallelism.
Range Partitioning
Range partitioning is a method whereby the partitioning of data is done based on the value of the data itself. This allows for tremendous flexibility in distributing data based on ranges of data values. Range partitioning allows you to partition high-volume data separately from low-volume data or to separate current from old data.
Local and Global Indexing
New Term: A local index indexes data that resides in only one partition. A global index indexes data that resides on more than one partition. This allows for great flexibility in terms of adding new indexes, reducing index sizes, and allowing for partition independence.
An example of where local indexing might be beneficial is a table where sales records are stored. Using table and index partitioning, you can store data and indexes separately based on calendar months; doing this allows reduced index size and faster index lookups for entries of a particular month. If you partition these entries you can add new months and delete outdated entries without reindexing the entire table. You could keep 12 months of partitions and indexes online in this manner.
Parallel Loading by Partition
With a partitioned table, SQL*Loader can either load an entire table in parallel by partition or simply load a single partition. Either method provides great flexibility.
If you use the conventional path load, the loader automatically distributes the data to the correct partition and updates the local and global indexes. You can also use the loader to load a partitioned table or a partition of a table. Again, indexes are built automatically. It is also possible to direct-load a partition in parallel provided that no global indexes exist, but you must rebuild the local indexes yourself.
Improved Parallelism
The arrival of Oracle8 has heralded tremendous improvement in the area of parallelization. In addition to the new parallel features listed previously, some existing parallel operations have been extended.
Parallel recovery has been improved by allowing rollbacks of parallel DML operations that have failed to be performed in parallel. This parallel transaction recovery is supported on transaction and process failures but not during instance recovery.
New parallel hints have been added for parallel insert operations. The APPEND hint tells the optimizer to append the insert data beyond the high water mark of the segment.
New Index Types
The index-only table is new in Oracle8. With traditional indexes and tables, data and indexes are stored separately. With an index-only table, the data to which the index refers is stored in the leaf block or lowest level block of the index, so the data and indexes are stored together. Depending on your application, this can be an advantage.
Applications that access data primarily via a key value can see an advantage from the use of index-only tables. Because the data is stored within the index, the data is immediately available when the index has reached its lowest level. This can speed data retrieval.
Applications that do not access data primarily via a key value will see no improvement; indeed, performance will likely be degraded in these applications. Any application that involves table scans or requires multiple indexes will not benefit from the index table.
Enhanced Recovery Features
Oracle has made tremendous improvements in the areas of backup and recovery. Most of these new features revolve around the Recovery Manager. Another recovery feature in Oracle8 is the image copy backup, which can improve recovery time in the event of a failure.
Recovery Manager
New Term: Recovery Manager is an online utility designed to assist the DBA with all backup and recovery operations. Not only does it perform the backup and recovery, it maintains a database called the recovery catalog that stores information about these operations.
Image Copy Backup
An image copy backup essentially allows you to copy a datafile to another place on disk or to another disk on your system. In the event of a failure, no recovery is necessary from the image copy; you must simply switch to that backup copy. You must, however, perform a recovery to make that copy current. In the event of a failure, this might be the fastest way to recover.
Oracle Products
As part of the overview of the Oracle system, I would like to briefly cover the optional available Oracle products. Although many of these products are covered elsewhere in this book, you should at least aware of their existence. The Oracle product line is divided into three areas:
* The Oracle server
* Development tools
* Applications
The Oracle Server
The Oracle server is the DBMS itself, and includes many options and features such as the Parallel Query option, network protocols, and advanced system administration options. Some of the key options available to the Oracle server include
* Enterprise Manager--This option is fairly new to Oracle, and consists of the management console and intelligent agents. The management console, which is the core element in Oracle's new graphical administrative package, runs only on Windows NT, but can manage any Oracle server. The console allows the DBA to graphically control one or more Oracle systems. The console can be used to configure and manage Oracle instances as well as to diagnose problems and can be configured to alert the DBA in the event of a problem.
* The keys to Enterprise Manager are the intelligent agents, which run on the Oracle server and provide the communication layer necessary for the console to communicate with these systems. The intelligent agents use industry-standard SNMP (Simple Network Management Protocols) to communicate with the console, thus allowing for future expansion.
NOTE:Throughout this book, Enterprise Manager is referenced as the primary method for administering the system. Nonetheless, command-line management is also covered.
* ConText--When integrated with any text system, Oracle ConText can analyze, filter, and reduce text for speed reading and summary viewing. Oracle ConText returns detailed assessments of the text it processes, checking for grammatical errors and rating the quality and style of the writing.
* Media Server--Oracle Media Server provides high-performance, scalable, and reliable multimedia library functions on a wide variety of general-purpose systems. Media Server handles the storage, retrieval, and management of movies, music, photographs, and text articles.
* The Spatial Data option--The Oracle Spatial Data option can be used to manage a database that contains spatial data. This option allows for the storage of spatial or geographical data. If you store the spatial data within the database, the complexity of managing the storage is reduced and the performance is increased.
* The Oracle Web server--The Oracle Web server is designed to provide front-end services to allow World Wide Web access to an Oracle database. This product allows Web users to retrieve information directly from an Oracle database rather than from traditional flat files. This product can be used to enhance the performance and functionality of your Web server via the use of indexes and data caching. With the flexibility of the Oracle RDBMS, the functionality of your Web server can be enhanced via the use of language-sensitive context and other features.
* The Internet Commerce server--The Internet Commerce server is a complete set of tools designed to help you create, run, and administer an Oracle system that is used for Web commerce. Because it is based on the proven technology of the Oracle server, the system can provide these services in a robust and secure fashion.
Development Tools
* One of Oracle's strongest points has been its development tools. Not only are these tools robust and full featured, they are flexible as well. When client/server systems became popular in the early 1990s, the Oracle tools quickly adapted. When HTML and Java applications became popular in the mid-1990s, the Oracle development tools quickly adapted yet again. The adaptability of these tools guarantees that applications developed with them can be quickly adjusted for new uses and technologies.Oracle provides the following tools:
* Designer/2000--This set of modeling tools reduces some of the pain associated with designing systems. These tools, which help with process and data modeling, can be used to provide input into the Developer/2000 system and to develop the fundamental models that are the foundation for your business processes.
* Developer/2000--This set of tools allows you to create an application and roll it out in Windows, Macintosh, Motif, and character mode. Developer/2000 incorporates graphics and images as well as support for multimedia objects such as video and sound in a variety of standard formats.
* Discoverer/2000--This data-analysis tool supports querying, reporting, and the graphical multidimensional analysis of the data warehouse. Its key features include graphical-representation and drill-down features.
* Power Objects--This lightweight, GUI development tool, which is available for Windows, Macintosh, and OS/2, allows the quick development of applications that use relatively small system resources. Power Objects is conceptually similar to Developer/2000, but lacks many of Developer/2000's features.
* Objects for OLE--This set of tools allows you to link OLE-compliant applications to an Oracle RDBMS. This tool provides a quick and easy way to exploit the power of applications such as spreadsheets. Objects for OLE also allows easy linking of database tables into word-processing documents.
* Programmer/2000--This suite of tools helps with the development of SQL, PL/SQL, and stored procedures. These tools can be helpful for application developers.
* Media Objects--Oracle's lightweight tool for developing multimedia applications, Media Objects supports client/server, CD-ROM, and interactive television processes.
* Database Designer--This lightweight version of the Oracle Designer/2000 product can assist in the design and creation of databases. Database Designer, a single-user tool, graphically designs the database tables and generates SQL that can be used to create this database.
Applications
Oracle's application software falls into two main categories: traditional applications and newer OLAP (Online Analytical Processing) applications.
Traditional Oracle Applications
Oracle's suite of traditional applications is used to perform basic and essential business tasks. These applications are used by many of the world's largest companies. The suite provides support for the following areas:
* Financial
* Human resources
* Project management
* Sales
* Manufacturing
OLAP Applications
The OLAP applications provide a graphical interface for DSS and data-warehousing applications. These tools lend a multidimensional model to the database, providing analysis, forecasting, and statistical operations.
Other Products
Oracle offers many other products that are not mentioned here. These products handle various tasks such as networking, office automation, workgrouping, and so on. Although these products and services are too numerous to cover here, rest assured that Oracle's full line can handle most (if not all) of your database and communication needs.
Oracle8 has introduced many new features, and I would like to focus on a few key features for the Oracle8 DBA:
* Partitioned objects
* Improved parallelism
* New index types
* Enhanced recovery features
Partitioned Objects
Partitioned objects allow Oracle objects, such as tables and indexes, to be broken into smaller, more manageable pieces. Partitioning these objects allows many operations that could normally be performed on only a table or an index to be divided into operations on a partition. By dividing these operations, you can often increase the parallelism of those operations, thus improving performance and minimizing system downtime.
Partitions are enabled via the PARTITION BY RANGE parameter of the CREATE TABLE statement. In this manner, ranges of data are assigned to each individual partition like so: CREATE TABLE emp (name CHAR(30),address CHAR(40),region INTEGER)PARTITION BY RANGE ( region)(PARTITION VALUES LESS THAN (10) TABLESPACE tbl0,PARTITION VALUES LESS THAN (20) TABLESPACE tbl1,PARTITION VALUES LESS THAN (30) TABLESPACE tbl2);
Table partitioning
Partitioning is recommended for large tables because it makes them much more manageable. Oracle does not currently support partitioning of clusters. By partitioning a table, you can break that large table into several much smaller pieces. A partitioned table can take advantage of some of the following features:
* Partitioned DML
* Exporting/importing by partition
* Range partitioning
* Local and global indexing
* Parallel loading by partition
Partitioned DML
Parallel INSERT, DELETE, and UPDATE operations can occur on a partition basis. Using partitions allows these operations to be conducted either globally or locally within a partition.
Exporting/Importing by Partition
Partitioning allows operations such as exports and imports to be performed on a partition basis. This can reduce the time required by some maintenance operations, such as reorganization of data or reclustering. This also allows you to change the physical layout of your database on a partition basis. If you limit the scope of export and import operations, they can benefit from a large degree of parallelism.
Range Partitioning
Range partitioning is a method whereby the partitioning of data is done based on the value of the data itself. This allows for tremendous flexibility in distributing data based on ranges of data values. Range partitioning allows you to partition high-volume data separately from low-volume data or to separate current from old data.
Local and Global Indexing
New Term: A local index indexes data that resides in only one partition. A global index indexes data that resides on more than one partition. This allows for great flexibility in terms of adding new indexes, reducing index sizes, and allowing for partition independence.
An example of where local indexing might be beneficial is a table where sales records are stored. Using table and index partitioning, you can store data and indexes separately based on calendar months; doing this allows reduced index size and faster index lookups for entries of a particular month. If you partition these entries you can add new months and delete outdated entries without reindexing the entire table. You could keep 12 months of partitions and indexes online in this manner.
Parallel Loading by Partition
With a partitioned table, SQL*Loader can either load an entire table in parallel by partition or simply load a single partition. Either method provides great flexibility.
If you use the conventional path load, the loader automatically distributes the data to the correct partition and updates the local and global indexes. You can also use the loader to load a partitioned table or a partition of a table. Again, indexes are built automatically. It is also possible to direct-load a partition in parallel provided that no global indexes exist, but you must rebuild the local indexes yourself.
Improved Parallelism
The arrival of Oracle8 has heralded tremendous improvement in the area of parallelization. In addition to the new parallel features listed previously, some existing parallel operations have been extended.
Parallel recovery has been improved by allowing rollbacks of parallel DML operations that have failed to be performed in parallel. This parallel transaction recovery is supported on transaction and process failures but not during instance recovery.
New parallel hints have been added for parallel insert operations. The APPEND hint tells the optimizer to append the insert data beyond the high water mark of the segment.
New Index Types
The index-only table is new in Oracle8. With traditional indexes and tables, data and indexes are stored separately. With an index-only table, the data to which the index refers is stored in the leaf block or lowest level block of the index, so the data and indexes are stored together. Depending on your application, this can be an advantage.
Applications that access data primarily via a key value can see an advantage from the use of index-only tables. Because the data is stored within the index, the data is immediately available when the index has reached its lowest level. This can speed data retrieval.
Applications that do not access data primarily via a key value will see no improvement; indeed, performance will likely be degraded in these applications. Any application that involves table scans or requires multiple indexes will not benefit from the index table.
Enhanced Recovery Features
Oracle has made tremendous improvements in the areas of backup and recovery. Most of these new features revolve around the Recovery Manager. Another recovery feature in Oracle8 is the image copy backup, which can improve recovery time in the event of a failure.
Recovery Manager
New Term: Recovery Manager is an online utility designed to assist the DBA with all backup and recovery operations. Not only does it perform the backup and recovery, it maintains a database called the recovery catalog that stores information about these operations.
Image Copy Backup
An image copy backup essentially allows you to copy a datafile to another place on disk or to another disk on your system. In the event of a failure, no recovery is necessary from the image copy; you must simply switch to that backup copy. You must, however, perform a recovery to make that copy current. In the event of a failure, this might be the fastest way to recover.
Oracle Products
As part of the overview of the Oracle system, I would like to briefly cover the optional available Oracle products. Although many of these products are covered elsewhere in this book, you should at least aware of their existence. The Oracle product line is divided into three areas:
* The Oracle server
* Development tools
* Applications
The Oracle Server
The Oracle server is the DBMS itself, and includes many options and features such as the Parallel Query option, network protocols, and advanced system administration options. Some of the key options available to the Oracle server include
* Enterprise Manager--This option is fairly new to Oracle, and consists of the management console and intelligent agents. The management console, which is the core element in Oracle's new graphical administrative package, runs only on Windows NT, but can manage any Oracle server. The console allows the DBA to graphically control one or more Oracle systems. The console can be used to configure and manage Oracle instances as well as to diagnose problems and can be configured to alert the DBA in the event of a problem.
* The keys to Enterprise Manager are the intelligent agents, which run on the Oracle server and provide the communication layer necessary for the console to communicate with these systems. The intelligent agents use industry-standard SNMP (Simple Network Management Protocols) to communicate with the console, thus allowing for future expansion.
NOTE:Throughout this book, Enterprise Manager is referenced as the primary method for administering the system. Nonetheless, command-line management is also covered.
* ConText--When integrated with any text system, Oracle ConText can analyze, filter, and reduce text for speed reading and summary viewing. Oracle ConText returns detailed assessments of the text it processes, checking for grammatical errors and rating the quality and style of the writing.
* Media Server--Oracle Media Server provides high-performance, scalable, and reliable multimedia library functions on a wide variety of general-purpose systems. Media Server handles the storage, retrieval, and management of movies, music, photographs, and text articles.
* The Spatial Data option--The Oracle Spatial Data option can be used to manage a database that contains spatial data. This option allows for the storage of spatial or geographical data. If you store the spatial data within the database, the complexity of managing the storage is reduced and the performance is increased.
* The Oracle Web server--The Oracle Web server is designed to provide front-end services to allow World Wide Web access to an Oracle database. This product allows Web users to retrieve information directly from an Oracle database rather than from traditional flat files. This product can be used to enhance the performance and functionality of your Web server via the use of indexes and data caching. With the flexibility of the Oracle RDBMS, the functionality of your Web server can be enhanced via the use of language-sensitive context and other features.
* The Internet Commerce server--The Internet Commerce server is a complete set of tools designed to help you create, run, and administer an Oracle system that is used for Web commerce. Because it is based on the proven technology of the Oracle server, the system can provide these services in a robust and secure fashion.
Development Tools
* One of Oracle's strongest points has been its development tools. Not only are these tools robust and full featured, they are flexible as well. When client/server systems became popular in the early 1990s, the Oracle tools quickly adapted. When HTML and Java applications became popular in the mid-1990s, the Oracle development tools quickly adapted yet again. The adaptability of these tools guarantees that applications developed with them can be quickly adjusted for new uses and technologies.Oracle provides the following tools:
* Designer/2000--This set of modeling tools reduces some of the pain associated with designing systems. These tools, which help with process and data modeling, can be used to provide input into the Developer/2000 system and to develop the fundamental models that are the foundation for your business processes.
* Developer/2000--This set of tools allows you to create an application and roll it out in Windows, Macintosh, Motif, and character mode. Developer/2000 incorporates graphics and images as well as support for multimedia objects such as video and sound in a variety of standard formats.
* Discoverer/2000--This data-analysis tool supports querying, reporting, and the graphical multidimensional analysis of the data warehouse. Its key features include graphical-representation and drill-down features.
* Power Objects--This lightweight, GUI development tool, which is available for Windows, Macintosh, and OS/2, allows the quick development of applications that use relatively small system resources. Power Objects is conceptually similar to Developer/2000, but lacks many of Developer/2000's features.
* Objects for OLE--This set of tools allows you to link OLE-compliant applications to an Oracle RDBMS. This tool provides a quick and easy way to exploit the power of applications such as spreadsheets. Objects for OLE also allows easy linking of database tables into word-processing documents.
* Programmer/2000--This suite of tools helps with the development of SQL, PL/SQL, and stored procedures. These tools can be helpful for application developers.
* Media Objects--Oracle's lightweight tool for developing multimedia applications, Media Objects supports client/server, CD-ROM, and interactive television processes.
* Database Designer--This lightweight version of the Oracle Designer/2000 product can assist in the design and creation of databases. Database Designer, a single-user tool, graphically designs the database tables and generates SQL that can be used to create this database.
Applications
Oracle's application software falls into two main categories: traditional applications and newer OLAP (Online Analytical Processing) applications.
Traditional Oracle Applications
Oracle's suite of traditional applications is used to perform basic and essential business tasks. These applications are used by many of the world's largest companies. The suite provides support for the following areas:
* Financial
* Human resources
* Project management
* Sales
* Manufacturing
OLAP Applications
The OLAP applications provide a graphical interface for DSS and data-warehousing applications. These tools lend a multidimensional model to the database, providing analysis, forecasting, and statistical operations.
Other Products
Oracle offers many other products that are not mentioned here. These products handle various tasks such as networking, office automation, workgrouping, and so on. Although these products and services are too numerous to cover here, rest assured that Oracle's full line can handle most (if not all) of your database and communication needs.
Oracle Architecture 4
System Memory Architecture
The system memory is basically a set of memory chips, either protected or not protected, that stores data and instructions used by the system. System memory can be protected by parity or by a more sophisticated advanced ECC correction method. Data parity will detect an incorrect value in memory and flag it to the system. An advanced ECC correction method will not only detect an incorrect value in memory, but in many cases can correct it. The system memory can range in size from 4MB on a small PC to 4GB on a large SMP server.
Typically, the more memory available to Oracle, the better your performance. Allocation of a large SGA allows Oracle to cache more data, thus speeding access to that data.
New Term:System memory is accessed by the CPUs through a high-speed bus that allows large amounts of data and instructions to be quickly moved from the CPU to L2 cache. Data and instructions are typically read from memory in large chunks and put into the cache. Because the CPU expects that memory will be read sequentially, in most cases it will read ahead the data or instruction that it thinks will be needed next. Sometimes this works, so the data that is needed next is already in cache; sometimes the CPU has guessed incorrectly and other data needs to be retrieved. This process of prereading the data is known as prefetching.
Depending on the specific implementation of an SMP system, the memory bus might be shared by all system processors; alternatively, each processor might have a private bus to memory.
Virtual Memory System
New Term:In a virtual memory system, the OS and hardware allow programs and users to use more memory than is actually available in the system hardware. This memory, known as virtual memory, can be mapped to physical memory. Code or data that is being run by the CPU must reside in physical memory. If a program or data that is larger than physical memory is being accessed, the parts of code and data that are not immediately needed by the program can reside in virtual memory, not physical memory. As that bit of code or data is needed, it can be copied into physical memory, and parts no longer needed can be copied to disk. The process of mapping virtual memory onto physical memory by copying the memory to and from disk is called paging or swapping (depending on the OS architecture).
Both paging and swapping serve the same purpose, but each operates slightly differently from the other. In a swapping system, an entire process is swapped out (moved from memory to disk) or swapped in (moved from disk to memory). In a paging system, the movement of data to and from the secondary storage occurs on a memory page basis; when more memory is needed, one or more pages is paged out (moved from memory to disk) to make room. A memory page is the smallest unit of memory that is used in the operating system. A typical memory page size is 4KB. If data is requested from virtual memory and is not in physical memory, that data is paged in (moved from disk to memory) as needed. The rest of this section uses the term paging to describe both paging and swapping.
Suppose you have a computer system with 16MB of physical memory. If you have a program that needs to access 20MB of data, it obviously won't fit in physical memory. In a virtual memory system, the data is read until little memory remains (the OS reserves some for itself), then the OS copies some of the data pages to disk with the paging mechanism. This is usually done using a least recently used algorithm in which the oldest data is moved out. When some memory has been freed, the program can read more data into memory. As far as the program is concerned, all the data is still in memory; in fact, it is--in virtual memory. As the program begins to reread some of the data and manipulate it, different pieces might be paged in (from disk to physical memory) and paged out (from physical memory to disk).
As you can imagine, paging in or out can be time consuming and uses a lot of system resources. This is why I warn you several times in this book to avoid using so much memory that you cause paging or swapping. Access to disk is approximately 50 times slower than access to memory.
Bus Design
New Term: Simply put, bus is a connection path used by the system to move data from one place to another. Buses get complicated when you look at them from a performance perspective: Capacity, or bandwidth, becomes an issue. Over the years, the term bandwidth, which was originally used to describe the electronic characteristics of a circuit, has been adopted by computer designers. In this case, bandwidth refers to the amount of data that can be transmitted across a bus in a certain time.
Several bus designs have been introduced in the last few years, all with the same goal: increased capacity. As processors, network hardware, disk controllers, and disks become increasingly fast, buses must develop to support the load generated by these devices. Thankfully, as computers have increased in performance, computer designers have improved bus designs to accommodate these changes. The system bus should not be a bottleneck in your system.
Oracle Resources
The Oracle DBMS allocates different resources for various different functions, including the allocation of system memory. The memory might be allocated for database caching or for the data dictionary or library cache. The careful balance of this precious resource is very important in tuning the Oracle RDBMS.
As much data as possible must be cached to avoid the additional cost of going to disk. If you allocate a large Oracle data cache, a higher cache-hit rate can be achieved. A high cache-hit rate indicates that a large percentage of requested data is found in the Oracle cache rather than retrieved from disk.
Application Design
Application design can affect performance more than any other factor. In most cases, performance can be severely degraded by an application that does not have well-tuned SQL statements or does not use indexes. A good application design can also significantly improve performance. The application is typically the first place to look when you experience system performance problems.
If a database is built with indexes on a certain set of columns but those columns are not specified in the WHERE clause of the SQL statement, the index probably won't be used. It's not enough to create the correct index on tables; you must ensure that the indexes are used.
TIP:It's wise to create a specification identifying the tables and indexes in your database. That way, the application developers and the team that creates the database have a crystal-clear document that identifies which columns are indexed. This can help avoid confusion and allow the application code to fully exploit the indexes.
Oracle Features
Another way to improve Oracle performance is to enable Oracle performance features. Among the most important of these features (and my personal favorite) is the Oracle Parallel Query option. Other Oracle performance features include partitioned tables and the Oracle index-only table, both new in Oracle8.
The Oracle Parallel Query Option
The Oracle Parallel Query option allows parallelism of many different operations, which greatly enhances performance. The Oracle Parallel Query option consists of several different components, including
* Parallel query
* Parallel index creation
* Parallel recovery
* Parallel table creation
* Parallel index tables
Parallel Query
The Oracle parallel query allows a single query to be divided into components and run in parallel. Because a query spends much of its time waiting for I/O operations to complete, parallelizing queries can greatly improve performance. In a well-tuned system where I/O is not a problem, parallel queries can run many times faster than normal queries. Statements that can be parallelized include
* Table scans
* Sorts
* Joins
NOTE: You might be wondering why parallelizing operations would help performance; after all, the work must still be done. In a typical Oracle operation (for example, a SELECT statement), the following steps occur:
1. Oracle performs some CPU processing to determine what data is needed.
2. Oracle submits an I/O request to disk (assuming that the data is not already in the SGA) and then waits for that I/O to complete.
3. This operation is repeated until all data is retrieved.
In the case of a parallel query, these steps would be adjusted like so:
1. Oracle performs some CPU processing to determine the query operation.
2. Different Oracle processes or threads receive their instructions on what data is needed.
3. Oracle thread 1 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
4. Oracle thread 2 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
5. Oracle thread 3 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
As shown here, that the time-consuming job of retrieving data from disk is duplicated, thus improving performance. This parallelism allows the CPU(s) to be utilized while other threads are waiting for I/Os.
Retrieving data from disk is a slow process compared to the activity of the CPU, and your goal is to keep the CPUs busy. Because a significant part of any Oracle operation involves CPU processing and I/Os, it is possible and desirable to keep the CPUs busy while many I/Os are being processed simultaneously. This is the main goal of the Parallel Query option.
Parallel Index Creation
Index creation involves reading from data tables and then writing to the index tables. Because the parallel query allows reading of tables to be accelerated, the index-creation process is sped up. Index creations can be quite time consuming, so this can be a real advantage.
Parallel Recovery
Recovery from a system failure can be quite time consuming. During recovery, users must usually wait for the system to come back online, so any improvement in performance is an advantage. Parallel recovery can speed the recovery process by parallelizing the read from the redo log files, and the roll forward and rollback process.
Parallel Table Creation
Although the Oracle Parallel Query option does not generally allow table creations to occur, it is often the case when a table is created as a subset of other tables. Data is often reduced from several large tables into a smaller subset, and this parallelism can be beneficial. In such instances, the following statement allows for parallelism:
CREATE TABLE table-name AS SELECT...
Oracle Index Tables
New to Oracle8, the index table allows indexes and tables to be stored together; this saves space and improves performance by reducing disk I/O. If you reduce the number of required disk I/Os, data can be accessed much faster.
OS Resources
New Term: In most systems, few resources can be allocated in the operating system. Most OS parameters are changed only to allocate sufficient resources to Oracle; additional resources usually do not improve performance. A lack of resources, however, can decrease performance. OS resources often refers to system memory or, in the case of UNIX, shared memory. Other OS resources and tunables include network buffers and disk I/O tunables.
TIP:Windows NT is fairly self tunable, but there are a few things, relating primarily to configuration, to look out for:
* Remove unnecessary network protocols--Depending on how the system is configured, several network protocols that you do not use might be configured into your system. These extra protocols use CPU and memory resources.
* Configure the protocols you use in order from most-often used to least-often used--This reduces some of the overhead associated with traversing the infrequently used protocols.
* Keep a close eye on paging--Windows NT treats all memory as virtual. The best way to determine whether your system is paging is to watch Pages/Sec in NT's perfmon. If paging occurs, lower the amount of memory allocated to Oracle.
Hardware
Several hardware factors can affect your system's performance. These factors include
* Memory capacity
* Number of CPUs
* CPU cache
* Memory-bus bandwidth
* I/O capacity
Memory Capacity
Earlier today you saw an overview of how the system hardware operates. Clearly, any operation that must access slower components, such as a disk or network, will slow down processing. Therefore, it is important that you have sufficient memory in your system.
New Term:Most hardware architectures are limited to 4GB of physical memory, but some architectures on the market support much more. These architectures are said to support a VLM, or Very Large Memory, architecture. Soon it will be possible to support hundreds of gigabytes of physical memory in a system, allowing for very fast RDBMS operations.
System memory is allocated to Oracle and used for database caching, user memory, and the shared pool, which is used for both the data dictionary and the library cache. You must have enough memory for the shared pool because an insufficient shared pool can hurt performance. When the shared pool is satisfied, the more database buffers you can allocate to the DBMS the better. Be careful, though, to avoid starving the PGA memory needed by your processes, and avoid paging at all costs. You can never have too much memory in your system. Anything that can be cached will reduce system I/O, improving performance.
Number of CPUs
Oracle typically scales well with additional CPUs. By adding CPUs you can see significant performance improvement with little additional cost. Some factors that determine how much improvement you will see by adding more processors are the CPU cache and memory- bus bandwidth.
CPU Cache
A large CPU cache allows more data and executable code to be stored on the local processor than in memory. This reduces the number of times the CPU must access main memory. Whenever the CPU accesses memory, a slowdown occurs while the CPU waits for that data or code to be retrieved. It is especially bad when the memory bus is busy; the CPU waits even longer until the bus becomes free.
Memory-Bus Bandwidth
The memory-bus bandwidth determines how quickly data can be transferred between CPU to memory. If the memory bus is busy when data or code is needed, a CPU stalls waiting for the bus to free. This can severely degrade performance in a multiprocessor computer. A fast memory bus can reduce this problem. A large CPU cache can also reduce this problem by allowing more data and code to be cached.
I/O Capacity
I/O is typically one of the biggest factors limiting system performance. Because most DBMS operations involve retrieving data from disk, I/O can be a limiting factor if you do not have adequate capacity for your system load. Fortunately, you can usually solve this problem by carefully configuring your system for proper I/O distribution and by having sufficient I/O capacity. Simply having adequate disk space is insufficient; you must also have enough disk drives to support the number of disk I/Os that the system requires.
The system memory is basically a set of memory chips, either protected or not protected, that stores data and instructions used by the system. System memory can be protected by parity or by a more sophisticated advanced ECC correction method. Data parity will detect an incorrect value in memory and flag it to the system. An advanced ECC correction method will not only detect an incorrect value in memory, but in many cases can correct it. The system memory can range in size from 4MB on a small PC to 4GB on a large SMP server.
Typically, the more memory available to Oracle, the better your performance. Allocation of a large SGA allows Oracle to cache more data, thus speeding access to that data.
New Term:System memory is accessed by the CPUs through a high-speed bus that allows large amounts of data and instructions to be quickly moved from the CPU to L2 cache. Data and instructions are typically read from memory in large chunks and put into the cache. Because the CPU expects that memory will be read sequentially, in most cases it will read ahead the data or instruction that it thinks will be needed next. Sometimes this works, so the data that is needed next is already in cache; sometimes the CPU has guessed incorrectly and other data needs to be retrieved. This process of prereading the data is known as prefetching.
Depending on the specific implementation of an SMP system, the memory bus might be shared by all system processors; alternatively, each processor might have a private bus to memory.
Virtual Memory System
New Term:In a virtual memory system, the OS and hardware allow programs and users to use more memory than is actually available in the system hardware. This memory, known as virtual memory, can be mapped to physical memory. Code or data that is being run by the CPU must reside in physical memory. If a program or data that is larger than physical memory is being accessed, the parts of code and data that are not immediately needed by the program can reside in virtual memory, not physical memory. As that bit of code or data is needed, it can be copied into physical memory, and parts no longer needed can be copied to disk. The process of mapping virtual memory onto physical memory by copying the memory to and from disk is called paging or swapping (depending on the OS architecture).
Both paging and swapping serve the same purpose, but each operates slightly differently from the other. In a swapping system, an entire process is swapped out (moved from memory to disk) or swapped in (moved from disk to memory). In a paging system, the movement of data to and from the secondary storage occurs on a memory page basis; when more memory is needed, one or more pages is paged out (moved from memory to disk) to make room. A memory page is the smallest unit of memory that is used in the operating system. A typical memory page size is 4KB. If data is requested from virtual memory and is not in physical memory, that data is paged in (moved from disk to memory) as needed. The rest of this section uses the term paging to describe both paging and swapping.
Suppose you have a computer system with 16MB of physical memory. If you have a program that needs to access 20MB of data, it obviously won't fit in physical memory. In a virtual memory system, the data is read until little memory remains (the OS reserves some for itself), then the OS copies some of the data pages to disk with the paging mechanism. This is usually done using a least recently used algorithm in which the oldest data is moved out. When some memory has been freed, the program can read more data into memory. As far as the program is concerned, all the data is still in memory; in fact, it is--in virtual memory. As the program begins to reread some of the data and manipulate it, different pieces might be paged in (from disk to physical memory) and paged out (from physical memory to disk).
As you can imagine, paging in or out can be time consuming and uses a lot of system resources. This is why I warn you several times in this book to avoid using so much memory that you cause paging or swapping. Access to disk is approximately 50 times slower than access to memory.
Bus Design
New Term: Simply put, bus is a connection path used by the system to move data from one place to another. Buses get complicated when you look at them from a performance perspective: Capacity, or bandwidth, becomes an issue. Over the years, the term bandwidth, which was originally used to describe the electronic characteristics of a circuit, has been adopted by computer designers. In this case, bandwidth refers to the amount of data that can be transmitted across a bus in a certain time.
Several bus designs have been introduced in the last few years, all with the same goal: increased capacity. As processors, network hardware, disk controllers, and disks become increasingly fast, buses must develop to support the load generated by these devices. Thankfully, as computers have increased in performance, computer designers have improved bus designs to accommodate these changes. The system bus should not be a bottleneck in your system.
Oracle Resources
The Oracle DBMS allocates different resources for various different functions, including the allocation of system memory. The memory might be allocated for database caching or for the data dictionary or library cache. The careful balance of this precious resource is very important in tuning the Oracle RDBMS.
As much data as possible must be cached to avoid the additional cost of going to disk. If you allocate a large Oracle data cache, a higher cache-hit rate can be achieved. A high cache-hit rate indicates that a large percentage of requested data is found in the Oracle cache rather than retrieved from disk.
Application Design
Application design can affect performance more than any other factor. In most cases, performance can be severely degraded by an application that does not have well-tuned SQL statements or does not use indexes. A good application design can also significantly improve performance. The application is typically the first place to look when you experience system performance problems.
If a database is built with indexes on a certain set of columns but those columns are not specified in the WHERE clause of the SQL statement, the index probably won't be used. It's not enough to create the correct index on tables; you must ensure that the indexes are used.
TIP:It's wise to create a specification identifying the tables and indexes in your database. That way, the application developers and the team that creates the database have a crystal-clear document that identifies which columns are indexed. This can help avoid confusion and allow the application code to fully exploit the indexes.
Oracle Features
Another way to improve Oracle performance is to enable Oracle performance features. Among the most important of these features (and my personal favorite) is the Oracle Parallel Query option. Other Oracle performance features include partitioned tables and the Oracle index-only table, both new in Oracle8.
The Oracle Parallel Query Option
The Oracle Parallel Query option allows parallelism of many different operations, which greatly enhances performance. The Oracle Parallel Query option consists of several different components, including
* Parallel query
* Parallel index creation
* Parallel recovery
* Parallel table creation
* Parallel index tables
Parallel Query
The Oracle parallel query allows a single query to be divided into components and run in parallel. Because a query spends much of its time waiting for I/O operations to complete, parallelizing queries can greatly improve performance. In a well-tuned system where I/O is not a problem, parallel queries can run many times faster than normal queries. Statements that can be parallelized include
* Table scans
* Sorts
* Joins
NOTE: You might be wondering why parallelizing operations would help performance; after all, the work must still be done. In a typical Oracle operation (for example, a SELECT statement), the following steps occur:
1. Oracle performs some CPU processing to determine what data is needed.
2. Oracle submits an I/O request to disk (assuming that the data is not already in the SGA) and then waits for that I/O to complete.
3. This operation is repeated until all data is retrieved.
In the case of a parallel query, these steps would be adjusted like so:
1. Oracle performs some CPU processing to determine the query operation.
2. Different Oracle processes or threads receive their instructions on what data is needed.
3. Oracle thread 1 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
4. Oracle thread 2 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
5. Oracle thread 3 submits an I/O request to disk (if that data is not already in the SGA) and waits for that I/O to complete.
As shown here, that the time-consuming job of retrieving data from disk is duplicated, thus improving performance. This parallelism allows the CPU(s) to be utilized while other threads are waiting for I/Os.
Retrieving data from disk is a slow process compared to the activity of the CPU, and your goal is to keep the CPUs busy. Because a significant part of any Oracle operation involves CPU processing and I/Os, it is possible and desirable to keep the CPUs busy while many I/Os are being processed simultaneously. This is the main goal of the Parallel Query option.
Parallel Index Creation
Index creation involves reading from data tables and then writing to the index tables. Because the parallel query allows reading of tables to be accelerated, the index-creation process is sped up. Index creations can be quite time consuming, so this can be a real advantage.
Parallel Recovery
Recovery from a system failure can be quite time consuming. During recovery, users must usually wait for the system to come back online, so any improvement in performance is an advantage. Parallel recovery can speed the recovery process by parallelizing the read from the redo log files, and the roll forward and rollback process.
Parallel Table Creation
Although the Oracle Parallel Query option does not generally allow table creations to occur, it is often the case when a table is created as a subset of other tables. Data is often reduced from several large tables into a smaller subset, and this parallelism can be beneficial. In such instances, the following statement allows for parallelism:
CREATE TABLE table-name AS SELECT...
Oracle Index Tables
New to Oracle8, the index table allows indexes and tables to be stored together; this saves space and improves performance by reducing disk I/O. If you reduce the number of required disk I/Os, data can be accessed much faster.
OS Resources
New Term: In most systems, few resources can be allocated in the operating system. Most OS parameters are changed only to allocate sufficient resources to Oracle; additional resources usually do not improve performance. A lack of resources, however, can decrease performance. OS resources often refers to system memory or, in the case of UNIX, shared memory. Other OS resources and tunables include network buffers and disk I/O tunables.
TIP:Windows NT is fairly self tunable, but there are a few things, relating primarily to configuration, to look out for:
* Remove unnecessary network protocols--Depending on how the system is configured, several network protocols that you do not use might be configured into your system. These extra protocols use CPU and memory resources.
* Configure the protocols you use in order from most-often used to least-often used--This reduces some of the overhead associated with traversing the infrequently used protocols.
* Keep a close eye on paging--Windows NT treats all memory as virtual. The best way to determine whether your system is paging is to watch Pages/Sec in NT's perfmon. If paging occurs, lower the amount of memory allocated to Oracle.
Hardware
Several hardware factors can affect your system's performance. These factors include
* Memory capacity
* Number of CPUs
* CPU cache
* Memory-bus bandwidth
* I/O capacity
Memory Capacity
Earlier today you saw an overview of how the system hardware operates. Clearly, any operation that must access slower components, such as a disk or network, will slow down processing. Therefore, it is important that you have sufficient memory in your system.
New Term:Most hardware architectures are limited to 4GB of physical memory, but some architectures on the market support much more. These architectures are said to support a VLM, or Very Large Memory, architecture. Soon it will be possible to support hundreds of gigabytes of physical memory in a system, allowing for very fast RDBMS operations.
System memory is allocated to Oracle and used for database caching, user memory, and the shared pool, which is used for both the data dictionary and the library cache. You must have enough memory for the shared pool because an insufficient shared pool can hurt performance. When the shared pool is satisfied, the more database buffers you can allocate to the DBMS the better. Be careful, though, to avoid starving the PGA memory needed by your processes, and avoid paging at all costs. You can never have too much memory in your system. Anything that can be cached will reduce system I/O, improving performance.
Number of CPUs
Oracle typically scales well with additional CPUs. By adding CPUs you can see significant performance improvement with little additional cost. Some factors that determine how much improvement you will see by adding more processors are the CPU cache and memory- bus bandwidth.
CPU Cache
A large CPU cache allows more data and executable code to be stored on the local processor than in memory. This reduces the number of times the CPU must access main memory. Whenever the CPU accesses memory, a slowdown occurs while the CPU waits for that data or code to be retrieved. It is especially bad when the memory bus is busy; the CPU waits even longer until the bus becomes free.
Memory-Bus Bandwidth
The memory-bus bandwidth determines how quickly data can be transferred between CPU to memory. If the memory bus is busy when data or code is needed, a CPU stalls waiting for the bus to free. This can severely degrade performance in a multiprocessor computer. A fast memory bus can reduce this problem. A large CPU cache can also reduce this problem by allowing more data and code to be cached.
I/O Capacity
I/O is typically one of the biggest factors limiting system performance. Because most DBMS operations involve retrieving data from disk, I/O can be a limiting factor if you do not have adequate capacity for your system load. Fortunately, you can usually solve this problem by carefully configuring your system for proper I/O distribution and by having sufficient I/O capacity. Simply having adequate disk space is insufficient; you must also have enough disk drives to support the number of disk I/Os that the system requires.
Oracle Architecture 3
What Affects Oracle Performance?
Because one of the roles of the DBA is to anticipate, find, and fix performance problems, you must know what types of things affect performance. To understand why these things affect performance, you must first review the basics of how a computer system works.
Overview of Computer Architecture
Your computer system consists of thousands of individual components that work in harmony to process data. Each of these components has its own job to perform, and each has its own performance characteristics.
The brainpower of the system is the Central Processing Unit (CPU), which processes all the calculations and instructions that run on the computer. The job of the rest of the system is to keep the CPU busy with instructions to process. A well-tuned system runs at maximum performance if the CPU or CPUs are busy 100% of the time.
So how does the system keep the CPUs busy? In general, the system consists of different layers, or tiers, of progressively slower components. Because faster components are typically the most expensive, you must perform a balancing act between speed and cost efficiency.
CPU and Cache
New Term:The CPU and the CPU's cache are the fastest components of the system. The cache is high-speed memory used to store recently used data and instructions so that it can provide quick access if this data is used again in a short time. Most CPU hardware designs have a cache built into the CPU chip. This internal cache is known as a Level 1 (or L1) cache. Typically, an L1 cache is quite small--8-16KB.
When a certain piece of data is wanted, the hardware looks first in the L1 cache. If the data is there, it's processed immediately. If the data is not available in the L1 cache, the hardware looks in the L2 cache, which is external to the CPU chip but located close to it. The L2 cache is connected to the CPU chip(s) on the same side of the memory bus as the CPU. To get to main memory, you must use the memory bus, which affects the speed of the memory access.
Although the L2 cache is twice as slow as the L1 cache, it's usually much larger. Its larger size means you have a better chance of getting a cache hit. Typical L2 caches range in size from 128KB to 4MB.
Slower yet is the speed of the system memory--it's probably five times slower than the L2 cache. The size of system memory can range from 4MB for a small desktop PC to 2-4GB for large server machines. Some supercomputers have even more system memory than that.
As you can see from the timeline shown in Figure 2.4, there is an enormous difference between retrieving data from the L1 cache and retrieving data from the disk. This is why you spend so much time trying to take advantage of the SGA in memory. This is also why hardware vendors spend so much time designing CPU caches and fast memory buses..
CPU Design
Most instruction processing occurs in the CPU. Although certain intelligent devices, such as disk controllers, can process some instructions, the instructions these devices can handle are limited to the control of data moving to and from the devices. The CPU works from the system clock and executes instructions based on clock signals. The clock rate and type of CPU determine how quickly these instructions are executed.
The CPU usually falls into one of two groups of processors: Complex Instruction Set Computer (CISC) or Reduced Instruction Set Computer (RISC).
CISC Processors
CISC processors (like the ones Intel builds) are by far the most popular processors. They are more traditional and offer a large instruction set to the program developer. Some of these instructions can be quite complicated; most instructions require several clock cycles to complete.
CISC processors are complex and difficult to build. Because these chips contain millions of internal components, the components are extremely close together. The physical closeness causes problems because there is no room for error. Each year, technology allows more complex and faster chips to be built, but eventually, physics will limit what can be done.
CISC processors carry out a wide range of tasks and can sometimes perform two or more instructions at a time in parallel. CISC processors perform most tasks, such as RDBMS processing, very well.
RISC Processors
RISC processors are based on the principle that if you can reduce the number of instructions processed by the CPU, the CPU can be simpler to build and can run faster. By putting fewer internal components inside the chip, the speed of the chip can be accelerated. One of the most popular RISC chips on the market is the DEC Alpha.
The system compiler determines what instructions are executed on the CPU chips. When the number of instructions was reduced, compilers were written to exploit this and to compensate for the missing instructions.
By reducing the instruction set, RISC manufacturers have been able to increase the clock speed to many times that of CISC chips. Although the faster clock speed is beneficial in some cases, it offers little improvement in others. One effect of a faster CPU is that the surrounding components such as L2 cache and memory must also run faster at an increase in cost.
One goal of some RISC manufacturers is to design the chip so that the majority of instructions complete within one clock cycle. Some RISC chips can already do this. But because some operations that require a single instruction for a CISC chip might require many instructions for a RISC chip, a speed-to-speed comparison cannot be made.
CISC versus RISCBoth CISC and RISC processors have their advantages and disadvantages; it's up to you to determine whether a RISC processor or a CISC processor will work best for you. When comparing the two types of processors, be sure to look at performance data and not just clock speed. Although the RISC chips have a much faster clock speed, they do less work per instruction. The performance of the system cannot be determined by clock speed alone.
Multiprocessor Systems
Multiprocessor systems can provide significant performance with very good value. With such a system, you can start with one or two processors and add more as needed. Multiprocessors fall into several categories; two of the main types of multiprocessor systems are the Symmetric Multiprocessor (SMP) system and the Massively Parallel Processing (MPP) system.
SMP Systems
SMP systems usually consist of a standard computer architecture with two or more CPUs that share the system memory, I/O bus, and disks. The CPUs are called symmetric because each processor is identical to any other processor in terms of function. Because the processors share system memory, each processor looks at the same data and the same operating system. In fact, the SMP architecture is sometimes called tightly coupled because the CPUs can even share the operating system.
* In the typical SMP system, only one copy of the operating system runs. Each processor works independently by taking the next available job. Because the Oracle architecture is based on many processes working independently, you can see great improvement by adding processors.
* The SMP system has these advantages:
* It's cost effective--The addition of a CPU or CPU board is much less expensive than adding another entire system.
* It's high performing--Under most applications, additional CPUs provide an incremental performance improvement.
* It's easily upgradable--Simply add a CPU to the system to instantly and significantly increase performance.
* A typical SMP system supports between four and eight CPUs. Because the SMP system shares the system bus and memory, only a certain amount of activity can occur before the bandwidth of the bus is saturated. To add more processors, you must go to an MPP architecture.
MPP Systems
MPP systems are based on many independent units. Each processor in an MPP system typically has its own resources (such as its own local memory and I/O system). Each processor in an MPP system runs an independent copy of the operating system and its own independent copy of Oracle. An MPP system is sometimes called loosely coupled.
Think of an MPP system as a large cluster of independent units that communicate through a high-speed interconnect. As with SMP systems, you will eventually hit the bandwidth limitations of the interconnect as you add processors. However, the number of processors with which you hit this limit is typically much larger than with SMP systems.
If you can divide the application among the nodes in the cluster, MPP systems can achieve quite high scalability. Although MPP systems can achieve much higher performance than SMP systems, they are less economical: MPP systems are typically much higher in cost than SMP systems.
CPU Cache
Regardless of whether you use a single-processor system, an SMP system, or an MPP system, the basic architecture of the CPUs is similar. In fact, you can find the same Intel processors in both SMP and MPP systems.
As you learned earlier today, the system cache is important to the system. The cache allows quick access to recently used instructions or data. A cache is always used to store and retrieve data more quickly than the next level of storage (the L1 cache is faster than the L2 cache, the L2 cache is faster than main memory, and so on).
By caching frequently used instructions and data, you increase the likelihood of a cache hit. This can save precious clock cycles that would otherwise have been spent retrieving data from memory or disk.
Because one of the roles of the DBA is to anticipate, find, and fix performance problems, you must know what types of things affect performance. To understand why these things affect performance, you must first review the basics of how a computer system works.
Overview of Computer Architecture
Your computer system consists of thousands of individual components that work in harmony to process data. Each of these components has its own job to perform, and each has its own performance characteristics.
The brainpower of the system is the Central Processing Unit (CPU), which processes all the calculations and instructions that run on the computer. The job of the rest of the system is to keep the CPU busy with instructions to process. A well-tuned system runs at maximum performance if the CPU or CPUs are busy 100% of the time.
So how does the system keep the CPUs busy? In general, the system consists of different layers, or tiers, of progressively slower components. Because faster components are typically the most expensive, you must perform a balancing act between speed and cost efficiency.
CPU and Cache
New Term:The CPU and the CPU's cache are the fastest components of the system. The cache is high-speed memory used to store recently used data and instructions so that it can provide quick access if this data is used again in a short time. Most CPU hardware designs have a cache built into the CPU chip. This internal cache is known as a Level 1 (or L1) cache. Typically, an L1 cache is quite small--8-16KB.
When a certain piece of data is wanted, the hardware looks first in the L1 cache. If the data is there, it's processed immediately. If the data is not available in the L1 cache, the hardware looks in the L2 cache, which is external to the CPU chip but located close to it. The L2 cache is connected to the CPU chip(s) on the same side of the memory bus as the CPU. To get to main memory, you must use the memory bus, which affects the speed of the memory access.
Although the L2 cache is twice as slow as the L1 cache, it's usually much larger. Its larger size means you have a better chance of getting a cache hit. Typical L2 caches range in size from 128KB to 4MB.
Slower yet is the speed of the system memory--it's probably five times slower than the L2 cache. The size of system memory can range from 4MB for a small desktop PC to 2-4GB for large server machines. Some supercomputers have even more system memory than that.
As you can see from the timeline shown in Figure 2.4, there is an enormous difference between retrieving data from the L1 cache and retrieving data from the disk. This is why you spend so much time trying to take advantage of the SGA in memory. This is also why hardware vendors spend so much time designing CPU caches and fast memory buses..
CPU Design
Most instruction processing occurs in the CPU. Although certain intelligent devices, such as disk controllers, can process some instructions, the instructions these devices can handle are limited to the control of data moving to and from the devices. The CPU works from the system clock and executes instructions based on clock signals. The clock rate and type of CPU determine how quickly these instructions are executed.
The CPU usually falls into one of two groups of processors: Complex Instruction Set Computer (CISC) or Reduced Instruction Set Computer (RISC).
CISC Processors
CISC processors (like the ones Intel builds) are by far the most popular processors. They are more traditional and offer a large instruction set to the program developer. Some of these instructions can be quite complicated; most instructions require several clock cycles to complete.
CISC processors are complex and difficult to build. Because these chips contain millions of internal components, the components are extremely close together. The physical closeness causes problems because there is no room for error. Each year, technology allows more complex and faster chips to be built, but eventually, physics will limit what can be done.
CISC processors carry out a wide range of tasks and can sometimes perform two or more instructions at a time in parallel. CISC processors perform most tasks, such as RDBMS processing, very well.
RISC Processors
RISC processors are based on the principle that if you can reduce the number of instructions processed by the CPU, the CPU can be simpler to build and can run faster. By putting fewer internal components inside the chip, the speed of the chip can be accelerated. One of the most popular RISC chips on the market is the DEC Alpha.
The system compiler determines what instructions are executed on the CPU chips. When the number of instructions was reduced, compilers were written to exploit this and to compensate for the missing instructions.
By reducing the instruction set, RISC manufacturers have been able to increase the clock speed to many times that of CISC chips. Although the faster clock speed is beneficial in some cases, it offers little improvement in others. One effect of a faster CPU is that the surrounding components such as L2 cache and memory must also run faster at an increase in cost.
One goal of some RISC manufacturers is to design the chip so that the majority of instructions complete within one clock cycle. Some RISC chips can already do this. But because some operations that require a single instruction for a CISC chip might require many instructions for a RISC chip, a speed-to-speed comparison cannot be made.
CISC versus RISCBoth CISC and RISC processors have their advantages and disadvantages; it's up to you to determine whether a RISC processor or a CISC processor will work best for you. When comparing the two types of processors, be sure to look at performance data and not just clock speed. Although the RISC chips have a much faster clock speed, they do less work per instruction. The performance of the system cannot be determined by clock speed alone.
Multiprocessor Systems
Multiprocessor systems can provide significant performance with very good value. With such a system, you can start with one or two processors and add more as needed. Multiprocessors fall into several categories; two of the main types of multiprocessor systems are the Symmetric Multiprocessor (SMP) system and the Massively Parallel Processing (MPP) system.
SMP Systems
SMP systems usually consist of a standard computer architecture with two or more CPUs that share the system memory, I/O bus, and disks. The CPUs are called symmetric because each processor is identical to any other processor in terms of function. Because the processors share system memory, each processor looks at the same data and the same operating system. In fact, the SMP architecture is sometimes called tightly coupled because the CPUs can even share the operating system.
* In the typical SMP system, only one copy of the operating system runs. Each processor works independently by taking the next available job. Because the Oracle architecture is based on many processes working independently, you can see great improvement by adding processors.
* The SMP system has these advantages:
* It's cost effective--The addition of a CPU or CPU board is much less expensive than adding another entire system.
* It's high performing--Under most applications, additional CPUs provide an incremental performance improvement.
* It's easily upgradable--Simply add a CPU to the system to instantly and significantly increase performance.
* A typical SMP system supports between four and eight CPUs. Because the SMP system shares the system bus and memory, only a certain amount of activity can occur before the bandwidth of the bus is saturated. To add more processors, you must go to an MPP architecture.
MPP Systems
MPP systems are based on many independent units. Each processor in an MPP system typically has its own resources (such as its own local memory and I/O system). Each processor in an MPP system runs an independent copy of the operating system and its own independent copy of Oracle. An MPP system is sometimes called loosely coupled.
Think of an MPP system as a large cluster of independent units that communicate through a high-speed interconnect. As with SMP systems, you will eventually hit the bandwidth limitations of the interconnect as you add processors. However, the number of processors with which you hit this limit is typically much larger than with SMP systems.
If you can divide the application among the nodes in the cluster, MPP systems can achieve quite high scalability. Although MPP systems can achieve much higher performance than SMP systems, they are less economical: MPP systems are typically much higher in cost than SMP systems.
CPU Cache
Regardless of whether you use a single-processor system, an SMP system, or an MPP system, the basic architecture of the CPUs is similar. In fact, you can find the same Intel processors in both SMP and MPP systems.
As you learned earlier today, the system cache is important to the system. The cache allows quick access to recently used instructions or data. A cache is always used to store and retrieve data more quickly than the next level of storage (the L1 cache is faster than the L2 cache, the L2 cache is faster than main memory, and so on).
By caching frequently used instructions and data, you increase the likelihood of a cache hit. This can save precious clock cycles that would otherwise have been spent retrieving data from memory or disk.
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