Dieting is Pactice of Ingesting Food Part 2

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.[4] 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.

Energy obtained from food

The energy humans get from food is limited by the efficiency of digestion and the efficiency of utilization. The efficiency of digestion is largely dependent on the type of food being eaten. Poorly chewed seeds are poorly digested. Refined sugars and fats are absorbed almost completely. Chewing does not compensate for the calorie content of a food that is eaten; even celery, which is primarily indigestible cellulose, contains enough sugars to easily compensate for the cost of chewing it.

Proper nutrition

Food provides nutrients from six broad classes: proteins, fats, carbohydrates, vitamins, dietary minerals, and water. Carbohydrates are metabolized to provide energy. Proteins provide amino acids, which are required for cell, especially muscle, construction. Essential fatty acids are required for brain and cell membrane construction. Vitamins and trace minerals help maintain proper electrolyte balance and are required for many metabolic processes.

Any diet that fails to meet minimum nutritional requirements can threaten general health (and physical fitness in particular). If a person is not well enough to be active, weight loss and good quality of life will be unlikely.

The National Academy of Sciences and the World Health Organization publish guidelines for dietary intakes of all known essential nutrients.

Sometimes dieters will ingest excessive amounts of vitamin and mineral supplements. While this is usually harmless, some nutrients are dangerous. Men (and women who don't menstruate) need to be wary of iron poisoning. Retinol (oil-soluble vitamin A) is toxic in large doses. As a general rule, most people can get the nutrition they need from foods (there are specific exceptions; vegans often need to supplement vitamin B12). In any event, a multivitamin taken once a day will suffice for the majority of the population.

A sensible weight-loss diet is a normal balanced diet; it just comes with smaller portions and perhaps some substitutions (e.g. low-fat milk, or less salad dressing). Extreme diets may lead to malnutrition, and are less likely to be effective at long-term weight loss in any event.

How the body gets rid of fat

All body processes require energy to run properly. When the body is expending more energy than it is taking in (e.g. when exercising), body cells rely on internally stored energy sources, like complex carbohydrates and fats, for energy. The first source the body turns to is glycogen, which is a complex carbohydrate created by the body. When that source is nearly depleted, the body begins lipolysis, the metabolism of fat for energy. In this process, fats, obtained from fat cells, are broken down into glycerol and fatty acids, which can be used to make energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.

Fats are also secreted by the sebaceous glands (in the skin).
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 as is drinking water and sleeping. (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 also common. Stimulants are often taken as a means to suppress (normal, healthy) hunger by people who are dieting. Ephedrine (through facilitating the release of adrenaline and noradrenaline) stimulates the alpha(1)-adrenoreceptor subtype, which is known to act as an anorectic. L-Phenylalanine, an amino acid found in whey protein powders also has the ability to suppress appetite by increasing the hormone cholecystokinin (CCK) which sends a satiety signal to the brain.

Weight loss groups

There exist both profit-oriented and non-profit weight loss organizations who assist people in their weight loss efforts. An example of the former is Weight Watchers ; examples of the latter include Overeaters Anonymous, as well as a multitude of non-branded support groups run by local churches, hospitals, and like-minded individuals.

These organizations' customs and practices differ widely. Some groups are modelled on twelve-step programs, while others are quite informal. Some groups advocate certain prepared foods or special menus, while others train dieters to make healthy choices from restaurant menus and while grocery-shopping and cooking.

Most groups leverage the power of group meetings to provide counseling, emotional support, problem-solving, and useful information.

Popular weight-loss diets

Popular diets (sometimes pejoratively called "fad diets") usually derive their popularity from the personalities of their proponents. These proponents include "diet gurus" and celebrity converts. "Diet books" are the primary means of communicating the specifics of popular diets.

Most popular diets experience short-lived popularity, partly because new diet books are continuously being published.

Judging the effectiveness (and nutritional merit) of popular diets can be especially difficult. Diet proponents often locate medical professionals to back up their work. Some diets are so controversial that they divide the medical community.

Many popular diets advocate the combination of a specific technique (such as eliminating a certain food, or eating only certain combinations of foods) with reduced caloric intake, with the goal being to accelerate weight loss. Others ignore traditional science altogether.

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. 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 high in refined carbohydrates (notably corn syrup), which may have contributed towards increased weight gain as carbohydrates (particularly refined carbohydrates) have a low nutrient density and high in calories. Some low-fat diets like the Pritikin diet focus on whole grains, vegetables and lean meats.

Atkins diet

Main article: Atkins Nutritional Approach

The Atkins diet was developed by Dr. Robert Atkins' and intended to control blood sugar by reducing the number of carbohydrates consumed (particularly refined carbohydrates) while replacing them with significant quantities of fat and protein. The Atkins diet was originally designed for diabetes patients who wanted to manage their insulin levels more effectively. The short-term changes experienced by individuals on the Atkins diet include some rapid weight-loss as the body's glycogen stores were depleted, reducing fasting levels of triglycerides and an increasing blood-bound ketones. The diet also causes acidosis and mild fatigue.

Natural diets

Since the advent of controversial diets such as Atkins, various diets that stress the eating habits of "natural humans" have been developed. The Paleolithic Diet imitates the way people ate during the Stone Age. These eating plans include basically natural foods (those not processed by humans). Whereas the Paleolithic Diet excludes milk and grain-foods, The Evolution Diet excludes human-made ingredients such as partially hydrogenated oils but allows some processed foods such as whole-grain crackers and dairy products. Anthropologists who focus their research on human evolution, however, are quick to point out that the diet of Paleolithic peoples was most likely opportunistic. That is, these early humans would most likely eat whatever edible foods were available at any given moment in that particular area (e.g. vegetables, termites, meat) and not restrict their intake of any food. Until recent human history, starvation has been a far greater threat than over-consumption.

Vegetarian diet

There is a growing body of evidence that vegetarian diets can prevent obesity and lower disease risks.

According to the American Dietetic Association, "Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer."

Vegetarians on average weigh 10 percent less than non-vegetarians. And in a year-long study comparing Dean Ornish's vegetarian diet to Weight Watchers, The Zone Diet, and The Atkins Diet, subjects on The Atkins Diet achieved the most weight loss (on average). Strict vegetarian diets like veganism may result in certain vitamin and mineral deficiencies if attention isn't paid to nutrition.

Weight Watchers

Main article: Weight Watchers

Weight Watchers has two programs. The program offers a wide variety and foods. Each food has a point value. They encourage a well rounded diet, low in fat and high in fruits and vegetables. The core plan focuses more on portion control and natural foods. According to Weight Watchers, the act of keeping track of what one eats is very helpful in reducing overeating or eating for reasons other than hunger.

Dangers

Extreme calorie restriction, medication or unusual patterns of eating (i.e. restricting food consumption to a single fruit or meal) can be dangerous.

Medications
Certain medications can be prescribed to assist in weight loss. Some, like amphetamines, are dangerous now banned for casual weight loss. Others, including those containing vitamins and minerals, are not effective for losing weight.

Diuretics
Diuretics induce weight loss through the excretion of water. These medication or herbs will reduce the amount that a body weighs, but will have no effect on an individual's body fat. Diuretics can thicken the blood, cause cramping, kidney and liver damage.

Stimulants
Stimulants such as ephedrine (now illegal in the United States due to an FDA ban) or synephrine work to increase the basal metabolic rate and reduce appetite. Stimulants can cause kidney and liver damage, sudden heart attacks, addiction, and ischemic strokes.

In June 2006, the European Union approved the sale of the diet drug rimonabant, marketed under the trade name Acomplia. This new class of diet pills shows some promise in assisting physician-prescribed diets.

Dangers of fasting

Main article: Fasting

Lengthy fasting can be dangerous due to the risk of malnutrition and should be carried out under medical supervision. During fasting, low-carbohydrate or very low calorie diets a lack of blood glucose, the preferred energy source of the brain, causes the body to metabolize sugars from protein, which can lead to muscle wasting.

Side effects

Dieting, especially extreme food-intake reduction and rapid weight loss, can have the following side effects:

* Prolonged hunger
* Depression
* Reduced sex drive
* Fatigue
* Irritability
* Fainting
* Sinus problems (especially post-nasal drip)
* Muscle atrophy
* Rashes
* Acidosis
* Bloodshot eyes
* Gallbladder disease
* Seizures
* Malnutrition, possibly leading to death


source: http://dietplanning.blogspot.com/2008/07/dieting-is-practice-of-ingesting-food.html