In the past three decades, the number of obese adults in the United States has doubled and the number of obese children almost tripled, which may lead to increased medical expenditures, productivity loss, and stress on the health care system. Economic analysis now shows that weight gain is the result of individual choices in response to economic environments and demonstrates that incentives can influence individual behaviors affecting weight. Determinants are varied and include year- and area-specific food prices, availability of food outlets and recreational facilities, health insurance, and minimum wage levels. Timely and important, "Economic Aspects of Obesity" provides a strong foundation for evaluating the costs and benefits of various proposals designed to control obesity rates.