In the context of physical health, weight loss is the process of losing body weight, typically by losing fat. Losing excess weight provides valuable benefits, such as better health, higher self-esteem, increased quality of life. To achieve weight loss, more calories must be expended than taken in. This can be achieved by reducing the amount of food consumed, increasing physical activity or a combination of the two. For healthy weight loss, most experts recommend a combination of healthy eating patterns and regular physical exercise. Other methods of losing weight include use of prescribed or herbal drugs or chemicals that decrease appetite and/or increase physical activity. Increasing metabolism can help enhance any weight loss plan, and eating breakfast in the morning can increase metabolism, as can eat smaller meals throughout the day. Eating four to six small meals, two to three hours apart, is usually recommended. Try not to go too long between meals, as even a five to six hour gap between meals can greatly slow down metabolism. Surgical options are also available. Liposuction removes targeted area of fat and tissue while bariatric surgeries can result in large weight loss by reducing the size of the stomach or reducing the absorption of food energy. But it is not appropriate for every one. Surgical and drug options may have serious side-effects. Weight loss hypnosis is yet another option for those wanting to lose weight. A loss of weight can also be the symptom of some mental or physical diseases or disorders, such as anorexia nervosa, cachexia associated with cancer, AIDS or diabetes. Weight loss can help to relieve symptoms of a variety of conditions, such as diabetes, back pain and disorders of the spine, pain in the knee or legs, and many heart conditions. For healthy weight loss, a physician should be consulted to develop a weight loss plan that is tailored to the individual.- Another key component of successful weight loss is setting a realistic goal and expectations. Many experts agree that a realistic goal for weight loss should be around 1 pound (half a kilo) per week. 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, vegan eats a diet completely devoid of animal products, including milk; but while this is a diet, it is not "dieting." The most common objective of dieting is loss of excess body fat. Some diets are prescribed for particular medical reasons, such as sodium-free diets, bland diets and soft food diets, while some dieting is actually designed to promote increase of body fat and/or of muscular weight gain. * Weight-loss diets restrict the intake of specific foods, or food in general, to reduce body weight. This is what "fad diets" are marketed for. There is a (sometimes confusing) multitude of weight loss techniques, many of which are ineffective. What works for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, it's important to note that dieting does not actually 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 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 such 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 their 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. 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, people should 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. For example, the uncooked diet tends to improve a participant's health. People's weight tends to nomalize due to the lack of fat in the diet. It also gives people a high amount of energy as uncooked food is easily matabolized. The diet makes you hungry because the food is easily digested, which constantly makes room for more. However, most people never put on weight while on this diet due to the low fat content. Besides, people should not mix cooked food with uncooked food while on this diet. The cooked food causes the stomach to produce acid, which does not mix well with the uncooked food and can creat indigestion. The Atkins Diet is a very popular diet. Dr. Robert Atkins' concept, somewhat exaggerated by the media, that a person can lose weight whilst gorging on meat, 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. Since the advent of controversial diets such as Atkins, various diets that stress the eating habits of "natural humans" have been developed. The Evolution Diet explains "what and how we were designed to eat"; the Paleolithic Diet imitates the way people ate during the Stone Ages. These eating plans include basically natural foods (those not processed by humans). Whereas the Paleolithic Diet exludes 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 (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. 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." Vegans 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 Dean Ornish's diet achieved the most weight loss (on average).