The Atkins Diet is a very popular diet. Dr. Robert Atkins' concept, somewhat exaggerated by the media, that a person can lose weight while eating significant quantities of fat and protein but strictly reducing carbohydrates, has captured the public's imagination. The success of those who tried the diet varied depending on the degree they adhered to the long term stages of the diet structure. The Atkins diet was originally designed for diabetes patients who wanted to manage their insulin levels more effectively. The diet was also embraced by those seeking a diet that allows eating to satiation.
Atkins discourages refined carbohydrate intake and encourages protein intake, especially in the form of meat. The diet encourages the consumption of fruits and non-starchy vegetables for the provision of fiber and nutrients; it takes a somewhat neutral stand on fat intake.
Many people experience rapid initial weight loss on Atkins, some of which is due to depletion of glycogen stores in the liver. Loss of glycogen is associated with loss of water weight, since the body stores up to four pounds of water for each pound of glycogen.
Low carbohydrate diets have been shown to reduce the fasting levels of triglycerides. Elevated triglycerides are a demonstrated risk factor for heart disease. (Low-fat diets also reduce fasting levels of triglycerides.)
A low-carbohydrate diet may not be suitable as a weight-maintenance diet (long-term). The products of fat metabolism (lipolysis) and protein metabolism (gluconeogenesis) include ketones which can be harmful.
Note: Any successful weight-loss diet will cause some acidosis; symptoms range from mild fatigue to severe joint pain. Acidosis can be controlled by drinking water (in large amounts) and taking antacid supplements (or eating vegetables grown in alkaline soil).
Monday, January 8, 2007
Low-fat Diets
Low-fat diets were popular during the 1980s and 1990s, encouraging people to eat foods low in fat (or without fat altogether) and instead eat foods high in carbohydrates. For instance, these diets told people to eat less fat junk food or sweet snacks, instead, you can choose low-calorie, and high-fiber foods like fruits and vegetables. These will help people feel full longer, and make any diet plan more effective. Also, plan your meals and buy the food you need so that you will not be tempted to turn to fast food when you are hungry.
The general public came to believe, partly due to information from low-fat diet proponents, that carbohydrates were "energy food" and that only fat made people fat. This led to high consumption of low-fat foods rich in refined carbohydrates (notably corn syrup), which led some people to gain more weight.
Some low-fat diets were healthier, focusing on consumption of whole grains, vegetables and lean meats. (See Pritikin diet.) But even these diets did not recognize the importance of essential fatty acids. Some low-fat foods were actually more harmful than the non-low-fat foods, since all fat was removed, both "good" and "bad."
The general public came to believe, partly due to information from low-fat diet proponents, that carbohydrates were "energy food" and that only fat made people fat. This led to high consumption of low-fat foods rich in refined carbohydrates (notably corn syrup), which led some people to gain more weight.
Some low-fat diets were healthier, focusing on consumption of whole grains, vegetables and lean meats. (See Pritikin diet.) But even these diets did not recognize the importance of essential fatty acids. Some low-fat foods were actually more harmful than the non-low-fat foods, since all fat was removed, both "good" and "bad."
Low-fat Diets
Low-fat diets were popular during the 1980s and 1990s, encouraging people to eat foods low in fat (or without fat altogether) and instead eat foods high in carbohydrates. For instance, these diets told people to eat less fat junk food or sweet snacks, instead, you can choose low-calorie, and high-fiber foods like fruits and vegetables. These will help people feel full longer, and make any diet plan more effective. Also, plan your meals and buy the food you need so that you will not be tempted to turn to fast food when you are hungry.
The general public came to believe, partly due to information from low-fat diet proponents, that carbohydrates were "energy food" and that only fat made people fat. This led to high consumption of low-fat foods rich in refined carbohydrates (notably corn syrup), which led some people to gain more weight.
Some low-fat diets were healthier, focusing on consumption of whole grains, vegetables and lean meats. (See Pritikin diet.) But even these diets did not recognize the importance of essential fatty acids. Some low-fat foods were actually more harmful than the non-low-fat foods, since all fat was removed, both "good" and "bad."
The general public came to believe, partly due to information from low-fat diet proponents, that carbohydrates were "energy food" and that only fat made people fat. This led to high consumption of low-fat foods rich in refined carbohydrates (notably corn syrup), which led some people to gain more weight.
Some low-fat diets were healthier, focusing on consumption of whole grains, vegetables and lean meats. (See Pritikin diet.) But even these diets did not recognize the importance of essential fatty acids. Some low-fat foods were actually more harmful than the non-low-fat foods, since all fat was removed, both "good" and "bad."
Psychological Aspects of Weight-Loss Dieting
Diets affect the "energy in" component of the energy balance by limiting or altering the distribution of foods. Techniques that affect the appetite can limit energy intake by affecting the desire to overeat.
Consumption of low-energy, fiber-rich foods, such as non-starchy vegetables, is effective in obtaining satiation (the feeling of "fullness"). Exercise is also useful in controlling appetite. (Extreme physical fatigue, such as experienced by soldiers and mountain climbers, can make eating a difficult chore.)
The use of drugs to control appetite is (potentially) dangerous. Stimulants are often taken as a means to ignore (normal, healthy) hunger by people who are not actually overweight. Even those who are overweight to the point that it will impact their long-term health are unlikely to benefit from complete fasting or radical changes.
Habitual or emotional eating is a common problem. Sufferers often turn to self-help books, hypnosis and group therapy. While these sources can sometimes be of assistance, dieters must beware. Some "diet gurus" are charlatans, others are well-meaning but focus on psychology or philosophy at the expense of practical solutions. Diets designed to appeal to people emotionally are often either very difficult to follow (i.e., too strict) or useless (i.e., too lenient).
Consumption of low-energy, fiber-rich foods, such as non-starchy vegetables, is effective in obtaining satiation (the feeling of "fullness"). Exercise is also useful in controlling appetite. (Extreme physical fatigue, such as experienced by soldiers and mountain climbers, can make eating a difficult chore.)
The use of drugs to control appetite is (potentially) dangerous. Stimulants are often taken as a means to ignore (normal, healthy) hunger by people who are not actually overweight. Even those who are overweight to the point that it will impact their long-term health are unlikely to benefit from complete fasting or radical changes.
Habitual or emotional eating is a common problem. Sufferers often turn to self-help books, hypnosis and group therapy. While these sources can sometimes be of assistance, dieters must beware. Some "diet gurus" are charlatans, others are well-meaning but focus on psychology or philosophy at the expense of practical solutions. Diets designed to appeal to people emotionally are often either very difficult to follow (i.e., too strict) or useless (i.e., too lenient).
Proper Nutrition
It is important to understand the difference between weight loss and fat loss. Weight loss typically involves the loss of fat, water and muscle. A dieter can lose weight without losing much fat. Ideally, overweight people should seek to lose fat and preserve muscle, since muscle burns more calories than fat. Generally, the more muscle mass one has, the higher one's metabolism is, resulting in more calories being burned, even at rest. Since muscles are more dense than fat, muscle loss results in little loss of physical bulk compared with fat loss. To determine whether weight loss is due to fat, various methods of measuring body fat percentage have been developed.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved. According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease. There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however. It has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved. According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease. There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however. It has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
Fat Loss versus Muscle Loss
It is important to understand the difference between weight loss and fat loss. Weight loss typically involves the loss of fat, water and muscle. A dieter can lose weight without losing much fat. Ideally, overweight people should seek to lose fat and preserve muscle, since muscle burns more calories than fat. Generally, the more muscle mass one has, the higher one's metabolism is, resulting in more calories being burned, even at rest. Since muscles are more dense than fat, muscle loss results in little loss of physical bulk compared with fat loss. To determine whether weight loss is due to fat, various methods of measuring body fat percentage have been developed.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved.
According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease. There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however. It has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved.
According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease. There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however. It has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
Physical Exercise
Physical exercise is an important complement to dieting in securing weight loss. Aerobic exercise is also an important part of maintaining normal good health, especially the muscular strength of the heart. To be useful, aerobic exercise requires maintaining a target heart rate of above 50 percent of one's maximum heart rate for 30 minutes, at least 3 times a week. Brisk walking can accomplish this.
The ability of a few hours a week of exercise to contribute to weight loss can be overestimated. To illustrate, consider a 100-kilogram man who wants to lose 10 kilograms and assume that he eats just enough to maintain his weight (at rest), so that weight loss can only come from exercise. Those 10 kilograms converted to work are equivalent to about 350 megajoules. (We use an approximation of the standard 37 kilojoules or 9 Calories per gram of fat.) Now assume that his chosen exercise is stairclimbing and that he is 20 percent efficient at converting chemical energy into mechanical work (this is within measured ranges). To lose the weight, he must ascend 70 kilometers. A man of normal fitness (like him) will be tired after 500 meters of climbing (about 150 flights of stairs), so he needs to exercise every day for 140 days (to reach his target).
The minimum safe dietary energy intake (without medical supervision) is 75 percent of that needed to maintain basal metabolism. For our hypothetical 100-kilogram man, that minimum is about 5,700 kilojoules (1,300 calories) per day. By combining daily aerobic exercise with a weight-loss diet, he would be able to lose 10 kilograms in half the time (70 days). Of course, the described regime is more rigorous than would be desirable or advisable for many persons. Therefore, under an effective but more manageable weight-loss program, losing 10 kilograms (about 20 pounds) may take as long as 6 months.
There are also some easy ways for people to exercise, such as walking rather than driving, climbing stairs instead of taking elevators, doing more housework with fewer power tools, or parking their cars farther and walking to school or the office.
The ability of a few hours a week of exercise to contribute to weight loss can be overestimated. To illustrate, consider a 100-kilogram man who wants to lose 10 kilograms and assume that he eats just enough to maintain his weight (at rest), so that weight loss can only come from exercise. Those 10 kilograms converted to work are equivalent to about 350 megajoules. (We use an approximation of the standard 37 kilojoules or 9 Calories per gram of fat.) Now assume that his chosen exercise is stairclimbing and that he is 20 percent efficient at converting chemical energy into mechanical work (this is within measured ranges). To lose the weight, he must ascend 70 kilometers. A man of normal fitness (like him) will be tired after 500 meters of climbing (about 150 flights of stairs), so he needs to exercise every day for 140 days (to reach his target).
The minimum safe dietary energy intake (without medical supervision) is 75 percent of that needed to maintain basal metabolism. For our hypothetical 100-kilogram man, that minimum is about 5,700 kilojoules (1,300 calories) per day. By combining daily aerobic exercise with a weight-loss diet, he would be able to lose 10 kilograms in half the time (70 days). Of course, the described regime is more rigorous than would be desirable or advisable for many persons. Therefore, under an effective but more manageable weight-loss program, losing 10 kilograms (about 20 pounds) may take as long as 6 months.
There are also some easy ways for people to exercise, such as walking rather than driving, climbing stairs instead of taking elevators, doing more housework with fewer power tools, or parking their cars farther and walking to school or the office.
Types of Diets
There are several kinds of diets:
Weight-loss diets restrict the intake of specific foods, or food in general, to reduce body weight. What works to reduce body weight for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, it's important to note that short-term dieting does not necessarily lead to weight loss in the long term. Reducing the body's food supply causes it to stockpile excess fat as a starvation response once normal eating is resumed - meaning crash dieting leads to small short-term weight loss, then an increase in weight shortly afterwards.
Many professional athletes impose weight-gain diets on themselves. For example, wrestlers may overeat in order to achieve a higher weight class. American football players may try to "bulk up" through weight-gain diets in order to gain an advantage on the field with a higher mass.
Medical conditions often require the following of special diets. Each of these diets will specifically include or exclude or regulate certain chemicals (and the foods that contain them). For example, a person who has diabetes is often on a diet designed to carefully manage his or her blood sugar level. Epileptics are often put on the Ketogenic Diet. Sufferers of celiac disease must follow a gluten-free diet, the lactose-intolerant are advised to omit milk products, and people with kidney disease must follow a strict low-sodium diet to ease the strain on their kidneys. Treatment of mild hypertension includes adhering to a diet rich in fruits and vegetables and low in fat and sodium. This diet may be tailored to focus on weight loss if that is necessary to control blood pressure. Some people show allergic reactions to different types of food. They may include but are not limited to wheat flour, nuts, various types of fruit, egg white etc. These foods are to be avoided in such cases. A special diet may be necessary to prevent health problems.
Weight-loss diets restrict the intake of specific foods, or food in general, to reduce body weight. What works to reduce body weight for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, it's important to note that short-term dieting does not necessarily lead to weight loss in the long term. Reducing the body's food supply causes it to stockpile excess fat as a starvation response once normal eating is resumed - meaning crash dieting leads to small short-term weight loss, then an increase in weight shortly afterwards.
Many professional athletes impose weight-gain diets on themselves. For example, wrestlers may overeat in order to achieve a higher weight class. American football players may try to "bulk up" through weight-gain diets in order to gain an advantage on the field with a higher mass.
Medical conditions often require the following of special diets. Each of these diets will specifically include or exclude or regulate certain chemicals (and the foods that contain them). For example, a person who has diabetes is often on a diet designed to carefully manage his or her blood sugar level. Epileptics are often put on the Ketogenic Diet. Sufferers of celiac disease must follow a gluten-free diet, the lactose-intolerant are advised to omit milk products, and people with kidney disease must follow a strict low-sodium diet to ease the strain on their kidneys. Treatment of mild hypertension includes adhering to a diet rich in fruits and vegetables and low in fat and sodium. This diet may be tailored to focus on weight loss if that is necessary to control blood pressure. Some people show allergic reactions to different types of food. They may include but are not limited to wheat flour, nuts, various types of fruit, egg white etc. These foods are to be avoided in such cases. A special diet may be necessary to prevent health problems.
Dieting
Dieting is the practice of eating (and drinking) in a regulated fashion to achieve a particular, short-term objective. This is distinct from the more basic concept of "diet," which addresses the longer-term and more generic habit of nutritional consumption. For example, a vegan eats a diet completely without animal products, including milk; while this is a diet, it is not "dieting."
The most common objective of dieting is loss of excess body fat. Some dieting is prescribed to achieve particular medical objectives, such as sodium-free diets, bland diets and soft food diets, while some dieting is actually designed to increase body fat and/or muscle weight gain.
The most common objective of dieting is loss of excess body fat. Some dieting is prescribed to achieve particular medical objectives, such as sodium-free diets, bland diets and soft food diets, while some dieting is actually designed to increase body fat and/or muscle weight gain.
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