(average of 33 kg). There is some evidence that fast weight loss produce greater long-term weight loss than gradual weight loss. Moderate on-site comprehensive lifestyle changes produce a greater weight loss than usual care, of 2 to 4 kg on average in 6 to 12 months. High-intensity comprehensive programs usually yield more weight loss than moderate or low-intensity, with about 35% to 60% of overweight individuals maintaining more than 5 kg weight loss after 2 years. The NICE devised a set of essential criteria to be met by commercial weight management organizations to be approved. The Transtheoretical Model (TTM) has been used as a framework to assist the design of lifestyle modification programmes, including weight management. A systematic review found that there is insufficient evidence to draw conclusions regarding the effects of TTM-based programs targeting weight loss that included dietary or physical activity interventions, or both (and also combined with other interventions), on sustainable weight loss (one year or longer) in overweight and obese adults. However, very low quality evidence points that this approach may induce positive changes in physical activity and dietary habits, such as increased in exercise duration and frequency, improvement in fruits and vegetables consumption, and reduced dietary fat intake. Medication Anti-obesity medications currently approved by the FDA for weight loss Several anti-obesity medications are currently approved by the FDA for long term use. Semaglutide (Wegovy) is currently approved by the FDA for long-term use, being associated with a 6-12% loss in body weight compared to placebo. The combination drug phentermine/topiramate (Qsymia) is approved by the FDA as an addition to a reduced-calorie diet and exercise for chronic weight management. Orlistat reduces intestinal fat absorption by inhibiting pancreatic lipase. Over the longer term, average weight loss on orlistat is . It leads to a reduced incidence of diabetes, and has some effect on cholesterol. However, there is little information on how it affects the longer-term complications or outcomes of obesity. Racemic amphetamine, phendimetrazine, diethylpropion, and phentermine are approved by the FDA for short term use. Other medications Bupropion, topiramate, and zonisamide are sometimes used off-label for weight loss. The usefulness of certain drugs depends upon the comorbidities present. Metformin is preferred in overweight diabetics and for those gaining weight because taking clozapine for schizophrenia, as it may lead to mild weight loss in comparison to sulfonylureas or insulin. The thiazolidinediones, on the other hand, may cause weight