A large number and range of policies to address the obesity epidemic have been implemented. However, the prevalence of obesity has continued to rise, or at best has leveled off, and many individual interventions have had disappointing results. This has led some people to question whether anything works to prevent or reduce obesity. In this essay I review the evidence on the effectiveness of antiobesity programs. Although some programs have had negligible effects, others have had small beneficial effects on diet, physical activity, and weight. Nutrition labels on packaged foods and calorie labels on menus have led to healthful reformulations of foods. Offering incentives for children to choose healthy foods, and for adults to go to the gym, have proven effective at changing behaviors. Precommitment mechanisms such as deposit contracts for weight loss and bariatric surgery are associated with weight loss but may not be ideal solutions for the majority of obese individuals. Certain comprehensive school-based interventions to change children's diets and promote physical activity have proved cost-effective. There is no magic bullet that will solve the problem of obesity, but numerous policies with modest beneficial effects, if enacted jointly, could result in meaningful change.