Types of diets Low-fat diets Low-fat diets involve the reduction of the percentage of fat in one’s diet. Calorie consumption is reduced because less fat is consumed. Diets of this type include NCEP Step I and II. A meta-analysis of 16 trials of 2–12 months’ duration found that low-fat diets (without intentional restriction of caloric intake) resulted in average weight loss of 3.2 kg (7.1 lb) over habitual eating. Low-carbohydrate diets Low carbohydrate diets such as Atkins and Protein Power are relatively high in protein and fats. Low-carbohydrate diets are sometimes ketogenic (i.e. they restrict carbohydrate intake sufficiently to cause ketosis). Low-calorie diets Low-calorie diets usually produce an energy deficit of 500–1,000 calories per day, which can result in a 0.5 kilogram (1.1 lb) to 1 kilogram (2.2 lb) weight loss per week. Some of the most commonly used low-calorie diets include DASH diet and Weight Watchers. The National Institutes of Health reviewed 34 randomized controlled trials to determine the effectiveness of low-calorie diets. They found that these diets lowered total body mass by 8% in the short term, over 3–12 months. Very low-calorie diets Very low calorie diets provide 200–800 calories per day, maintaining protein intake but limiting calories from both fat and carbohydrates. They subject the body to starvation and produce an average weekly weight loss of 1.5–2.5 kilograms (3.3–5.5 lb). “2-4-6-8”, a popular diet of this variety, follows a four-day cycle in which only 200 calories are consumed the first day, 400 the second day, 600 the third day, 800 the fourth day, 1,000 the fifth day, and then the cycle repeats. These diets are not recommended for general use as they are associated with adverse side effects such as loss of lean muscle mass, increased risks of gout, and electrolyte imbalances. People attempting these diets must be monitored closely by a physician to prevent complications. Calorie counting Each pound of body fat is maintained by less than one extra calorie per hour. In general, obesity is not a condition maintained by overeating; obesity is a condition brought about and maintained by eating more calories than the body uses, consistently. As a practical example, eating twenty-five Burger King Whoppers rather than twenty-five McDonald Quarter Pounders can cause a weight gain of more than one and one-half pounds in that year. Twenty-five hamburgers represent 2% of yearly allotment of three meals a day. Making comparable choices at every meal for one year could yield an eighty-two-pound difference in body weight. This is the reason why extremely obese individuals who have actually been consuming around 4000 calories per day could slim down quicker than lighter individuals, because they can lower their consumption by much more per day and still consume enough to sustain themselves. Detox diets Detox diets claim to eliminate undesirable “toxins” from the human body rather than claiming to cause weight loss. Many of these use herbs, homeopathic remedies, or celery and other juicy low-calorie vegetables.