Dietary supplements, though widely used, are not considered a healthy option for weight loss, and have no clinical evidence of efficacy. Herbal products have not been shown to be effective.In 2008, between US$33 billion and $55 billion was spent annually in the US on weight-loss products and services, including medical procedures and pharmaceuticals, with weight-loss centers taking between 6 and 12 percent of total annual expenditure. Over $1.6 billion per year was spent on weight-loss supplements. About 70 percent of Americans dieting attempts are of a self-help nature.In Western Europe, sales of weight-loss products, excluding prescription medications, topped €1,25 billion (£900 million/$1.4 billion) in 2009.The scientific soundness of commercial diets by commercial weight management organizations varies widely, being previously non-evidence-based, so there is only limited evidence supporting their use, because of high attrition rates. Commercial diets result in modest weight loss in the long term, with similar results regardless of the brand, and similarly to non-commercial diets and standard care. Comprehensive diet programs, providing counseling and targets for calorie intake, are more efficient than dieting without guidance ("self-help"), although the evidence is very limited. The National Institute for Health and Care Excellence devised a set of essential criteria to be met by commercial weight management organizations to be approved. Unintentional
Characteristics
Unintentional weight loss may result from loss of body fats, loss of body fluids, muscle atrophy, or a combination of these.
Self-monitoring of diet, exercise, and weight are beneficial strategies for weight loss, particularly early in weight loss programs. Research indicates that those who log their foods about three times per day and about 20 times per month are more likely to achieve clinically significant weight loss.Weight loss depends on maintaining an negative energy balance and not the type of macronutrients (such as carbohydrate) consumed. High protein diets have shown greater efficacy in the short term for people eating ad libitum due to increased thermogenesis and satiety. Medications
Other methods of weight loss include use of anti-obesity drugs that decrease appetite, block fat absorption, or reduce stomach volume. Obesity has been resistant to drug-based therapies, with a 2021 review stating that existing medications are "often delivering insufficient efficacy and dubious safety". Bariatric surgery
Bariatric surgery may be indicated in cases of severe obesity. Two common bariatric surgical procedures are gastric bypass and gastric banding. Both can be effective at limiting the intake of food energy by reducing the size of the stomach, but as with any surgical procedure both come with their own risks that should be considered in consultation with a physician. Weight loss industry
There is a substantial market for products which claim to make weight loss easier, quicker, cheaper, more reliable, or less painful. These include books, DVDs, CDs, cremes, lotions, pills, rings and earrings, body wraps, body belts and other materials, fitness centers, clinics, personal coaches, weight loss groups, and food products and supplements.