mechanism for its effectiveness is unclear. the mediterranean diet is characterized by high consumption of vegetables, fruits, legumes, whole-grain cereals, seafood, olive oil, and nuts. red meat, dairy and alcohol are only recommended in moderation. studies show that the mediterranean diet is associated with short term as well as long term weight loss in addition to health and metabolic benefits. detox detox diets are promoted with unsubstantiated claims that they can eliminate "toxins" from the human body. many of these diets use herbs or celery and other juicy low-calorie vegetables. detox diets can include fasting or exclusion (as in juice fasting). detox diets tend to result in short-term weight loss (because of calorie restriction), followed by weight gain. environmentally sustainable another kind of diet focuses not on the dieter's health effects, but on its environment. the one blue dot plan of the bda offers recommendations towards reducing diets' environmental impacts, by: reducing meat to 70g per person per day. prioritising plant proteins. promoting fish from sustainable sources. moderate dairy consumption. focusing on wholegrain starchy foods. promoting seasonal locally sourced fruits and vegetables. reducing high fat, sugar and salty foods overconsumption. promoting tap water and unsweetened tea/coffee as the de facto choice for healthy hydration. reducing food waste. effectiveness several diets are effective for short-term weight loss for obese individuals, with diet success most predicted by adherence and little effect resulting from the type or brand of diet. as weight maintenance depends on calorie intake, diets emphasising certain macronutrients (low-fat, low-carbohydrate, etc.) have been shown to be no more effective than one another and no more effective than diets that maintain a typical mix of foods with smaller portions and perhaps some substitutions (e.g. low-fat milk, or less salad dressing). a meta-analysis of six randomized controlled trials found no difference between low-calorie, low-carbohydrate, and low-fat diets in terms of short-term weight loss, with a 2–4 kilogram weight loss over 12–18 months in all studies. diets that severely restrict calorie intake do not lead to long term weight loss. extreme diets may, in some cases, lead to malnutrition. a major challenge regarding weight loss and dieting relates to compliance. while dieting can effectively promote weight loss in the short term, the intervention is hard to maintain over time and suppresses skeletal muscle thermogenesis. suppressed thermogenesis accelerates weight regain once the diet stops, unless that phase is accompanied by a well-timed exercise intervention, as described by the summermatter cycle. most diet studies do not assess long-term weight loss. some studies have found that, on average, short-term dieting results in a "meaningful" long-term weight-loss, although limited because of gradual 1 to 2 kg/year weight regain. because people who do not participate in weight-loss programs also tend to gain weight over time, and baseline data from such "untreated" participants are typically not included in diet studies, it is possible that diets do result in lower weights in the long-term relative to people who do not diet. others have suggested that dieting is ineffective as a long-term intervention. for each individual, the results will be different, with some even regaining more weight than they lost, while a few others achieve a tremendous loss, so that the "average weight loss" of a diet is not indicative of the results other dieters may achieve. a 2001 meta-analysis of 29 american studies found that participants of structured weight-loss programs maintained an average of 23% (3 kg) of their initial weight loss after five years, representing a sustained 3.2% reduction in body mass. unfortunately, patients are generally unhappy with weight loss of <10%, and reductions even as high as 10% are insufficient for changing someone with an "obese" bmi to a "normal weight" bmi. partly because diets do not reliably produce long-term positive health outcomes, some argue against using weight loss as a goal, preferring other measures of health such as improvements in cardiovascular biomarkers, sometimes called a health at every size (haes) approach or a "weight neutral" approach. long term losses from dieting are best maintained with continuing professional support, long term increases in physical activity, the use of anti-obesity medications, continued use of meal replacements, and additional periods of dieting to undo weight regain. the most effective approach to weight loss is an in-person, high-intensity, comprehensive lifestyle intervention: overweight or obese adults should maintain regular (at least monthly) contact with a trained interventionalist who can help them engage in exercise, monitor their body weight, and reduce their calorie consumption. even with high-intensity, comprehensive lifestyle interventions (consisting of diet, physical exercise, and bimonthly or even more frequent contact with trained interventionists), gradual weight regain of 1–2 kg/year still occurs. for patients at high medical risk, bariatric surgery or medications may be warranted in addition to the lifestyle intervention, as dieting by itself may not lead to sustained weight loss. many studies overestimate the benefits of calorie restriction because the studies confound exercise and diet (testing the effects of diet and exercise as a combined intervention, rather than the effects of diet alone). increased mortality rate a number of studies have found that intentional weight loss is associated with an increase in mortality in people without weight-related health problems. a 2009 meta-analysis of 26 studies found that "intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors), especially unhealthy obese, but appeared to be associated with slightly increased mortality for healthy individuals, and for those who were overweight but not obese." dietary supplements due to extreme or unbalanced diets, dietary supplements are sometimes taken in an attempt to replace missing vitamins or minerals. while some supplements could be helpful for people eating an unbalanced diet (if replacing essential nutrients, for example), overdosing on any dietary supplement can cause a range of side effects depending on the supplement and dose that is taken. supplements should not replace foods that are important to a healthy diet. eating disorders in an editorial for psychological medicine, george hsu concludes that dieting is likely to lead to the development of an eating disorder in the presence of certain risk factors. a 2006 study found that dieting and unhealthy weight-control behaviors were predictive of obesity and eating disorders five years later, with the authors recommending a "shift away from dieting and drastic weight-control measures toward the long-term implementation of healthful eating and physical activity". mechanism when the body is expending more energy than it is consuming (e.g. when exercising), the body's cells rely on internally stored energy sources, such as complex carbohydrates and fats, for energy. the first source to which the body turns is glycogen (by glycogenolysis). glycogen is a complex carbohydrate, 65% of which is stored in skeletal muscles and the remainder in the liver (totaling about 2,000 kcal in the whole body). it is created from the excess of ingested macronutrients, mainly carbohydrates. when glycogen is nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. in this process fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to generate energy. the primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system. set-point theory the set-point theory, first introduced in 1953, postulated that each body has a preprogrammed fixed weight, with regulatory mechanisms to compensate. this theory was quickly adopted and used to explain failures in developing effective and sustained weight loss procedures. a 2019 systematic review of multiple weight change procedures, including alternate day fasting and time-restricted feeding but also exercise and overeating, found systematic "energetic errors" for all these procedures. this shows that the body cannot precisely compensate for errors in energy/calorie intake, countering the set-point theory and potentially explaining both weight loss and weight gain such as obesity. this review was conducted on short-term studies, therefore such a mechanism cannot be excluded in the long term, as evidence is currently lacking on this timeframe. methods meals timing meals timing schedule is known to be an important factor of any diet. recent evidence suggest that new scheduling strategies, such as intermittent fasting or skipping meals, and strategically placed snacks before meals, may be recommendable to reduce cardiovascular risks as part of a broader lifestyle and dietary change. food diary a 2008 study published in the american journal of preventive medicine showed that dieters who kept a daily food diary (or diet journal), lost twice as much weight as those who did not keep a food log, suggesting that if a person records their eating, they are more aware of what they consume and therefore eat fewer calories. water a 2009 review found limited evidence suggesting that encouraging water consumption and substituting energy-free beverages for energy-containing beverages (i.e., reducing caloric intake) may facilitate weight management. a 2009 article found that drinking 500 ml of water prior to meals for a 12-week period resulted in increased long-term weight reduction. 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