Dieting
Medical conditions often require the use of a special diet that either contains or lacks certain chemicals. A person who has diabetes is often on a diet designed to carefully regulate their blood sugar level, sufferers of celiac disease must follow a gluten-free diet, the lactose-intolerant omit milk and dairy products, and people with kidney disease must follow a strict low-sodium diet to ease the strain on their kidneys.
Certain religions, including Judaism and Islam, also impose strict restrictions on diet, but these are not usually thought of as "dieting".
Most typically "dieting" means eating in a carefully planned way in an attempt to reduce excess body fat and decrease bodily measurements and clothing size. In this sense, there are a number of so-called diets that can be used as part of a regimen of dieting. Also in this sense, excessive dieting is related to anorexia nervosa and bulimia, which are life-threatening conditions. There are many organisations, such as Weight Watchers and Jenny Craig, that support weight loss efforts on a for-profit basis, by providing prepared food or special menus and individual or group counselling sessions, as well as teaching exercise routines, with the aim of improving clients' lifestyles and enabling them to maintain successful weight loss. It is highly questionable as to the overall long-term success of these diets, however, as many people gain the weight they've lost back - and then some.
There are as many different recommendations for supposedly successful diets as there are people trying to lose weight. What works for one person will not necessarily work for another due to metabolic differences and lifestyle factors. Many 'fad' diets become popular for a short space of time - the grapefruit diet as well as Atkins are good examples of this. On the grapefruit diet, the consumption of grapefruit with each meal was said to increase the metabolic rate, burning fat and enabling rapid weight loss. Like most fad diets, the grapefruit diet was eventually found to be entirely ineffective, and it was replaced by the next fad - Atkins. Atkins encouraged cutting out carbohydrates and encouraged foods such as red meat, which led to a strong commercial effort to popularize beef.
The Very Low Calorie Diet, or VLCD, is a special diet to be undertaken with medical supervision. It offers rapid fat loss over a short timeframe, but can be dangerous for some people. It consists of the consumption of a special powder mixed in with 200-300ml of water to be taken three times a day. The drink, similar to a milkshake, provides approximately 1914Kj (456 Cal) of energy per day when consumed at breakfast, lunch and dinner. It contains all necessary vitamins and minerals, although there is a risk of overdosing on Selenium if a person consumes more than they should (more than three times per day). VLCD's should only be used for dieting when a person's Body mass index exceeds 30. In addition, at least 2 litres of water must be consumed per day and a person should consider using fibre supplements regularly. Without this, the person risks severe constipation.
Successful weight loss diet is all about energy in vs. energy out. If a person takes in fewer calories than he or she expends over a period of time, the person may burn fat and subsequently lose weight. To lose a pound of fat, one must create a caloric deficit of approximately 3,500 calories; therefore, if a person creates a deficit of 500 calories per day, the person will lose approximately 1 pound of fat per week. However, these numbers are strictly "in theory," and again what works for one person usually will not work for all.
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. This can be attempted by focusing on foods that are filling, through the use of certain appetite supressing drugs, or through activities such as mild exercise, that affect appetite. Other techniques address habitual or emotional eating.
Affecting the "energy out" component is the focus of fitness and exercise programs. These might also be included in a comprehensive "diet".
Dieting has hazards that are rarely pointed out. Yo-yo dieting is particularly dangerous and ineffective, because it decreases the metabolism, leading to an immediate weight gain once the caloric restrictions are eased. Some dieters resort to over the counter (OTC) and/or prescribed medications to improve their results, but many of these have been proven to be extremely hazardous to the health (and consequently withdrawn from sale) so consumers need to be wary.
The only "safe" method of weight loss is to eat a sensible healthy diet with a moderately decreased caloric intake from your norm, and to increase exercise gradually until weight loss results. It should be noted that people may follow these guidelines and not actually lose weight, but may see health improvements.
See: Diet, List of diets, Food faddism, Appetite suppressantMedical diets
Religious diets
Weight loss
Fad diets
Very Low Calorie Diets
VLCD's can be very successful but only when used over a 6-12 week period. Because the body is essentially starving, it is burning up its fat stores and lowering its metabolic rate. As soon as the diet ceases and normal food is consumed again, there is an immediate increase in weight. Short-term use of VLCDs (1-4 weeks) will have little, if any, benefit for the dieter as the increase in weight will negate the weight lost in the first place. Once the full course of the diet is finished, it is up to the successful dieter to maintain their current weight via exercise and sensible eating, otherwise they will put on weight again. VLCD's put a great deal of strain on a person's body, and should only be undertaken with medical consultation.Dieting principles
Hazards