Conventional diets and increased exercise are the cornerstones of traditional therapy for obesity, but available data suggest that the most important component of any program is the associated behavior modification through which new ways of dealing with old problems can be learned and continually applied. This combined with very-low-calorie diets--less than 800 kcal per day--are in wide use, mostly under medical supervision. The currently available appetite-suppressing drugs are of limited efficacy, but many new ones are under active development and hold promise for the future. The most effective surgical intervention appears to be the gastric bypass operation, but this should be reserved for those who are at high risk from their obesity.