DietingDieting is the practice or habit of eating (and drinking) in a regulated fashion with the aim of losing (or, sometimes, gaining) weight, or in some cases to regulate the amounts of certain nutrients.
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.
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. There is some doubt as to the effectiveness of these schemes in the long term: if they were as successful as claimed they wouldn't have a viable long-term business base - everyone who wanted to be would be thin!
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 is a good example of this. 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.
A 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 will 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. Preferably, this deficit should be accomplished with a combination of decreased calories and increased activity.
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 proven 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.