Successful treatment of obesity is challenging, and treatment goals vary, depending on the age of the child and the severity of complications from being overweight. Children are still growing, so severe caloric restriction and weight loss may be detrimental. Weight maintenance rather than weight loss is frequently a reasonable initial goal. As children grow in stature, BMI decreases. Weight loss should be attempted only in skeletally mature children or in those with serious complications from obesity. Weight loss should be slow (1 lb or 0.5 kg or less/wk), because more rapid weight loss requires overly restrictive dieting. An initial goal of a 10% reduction in weight is reasonable because this amount of weight loss has been shown to significantly improve overall health. Once achieved, the new weight should be maintained for 6 months before further weight loss is attempted. Successful long-term weight loss in adults is uncommon, despite the wide variety of diet plans and commercial products. There is a propensity to regain weight and adapt unhealthy behaviors with recurrent fad dieting. The most successful approach to weight maintenance or weight loss requires substantial lifestyle changes that include increased physical activity and altered eating habits. Similar approaches are used to prevent weight gain in children who are at risk for overweight and to promote weight maintenance or weight loss in overweight children. Therapies often combine diet, exercise, behavior modification, medications, and rarely, surgery. There is no clear and universally accepted treatment approach, but there are some generally accepted principles.