Mary Story, Karen Kaphingst, and Simone French argue that U.S. schools offer many opportunities for developing obesity-prevention strategies by providing more nutritious food, offering greater opportunities for physical activity, and providing obesity-related health services. Meals at school are available both through the U.S. Department of Agriculture's school breakfast and lunch programs and through "competitive foods" sold a la carte in cafeterias, vending machines, and snack bars. School breakfasts and school lunches must meet federal nutrition standards, but competitive foods are exempt from such requirements. And budget pressures force schools to sell the popular but nutritionally poor foods a la carte. Public discomfort with the school food environment is growing. But can schools provide more healthful food options without losing money? Limited evidence shows that they can. Although federal nutrition regulations are inadequate, they permit state and local authorities to impose additional restrictions. And many are doing so. Some states limit sales of nonnutritious foods, and many large school districts restrict competitive foods. Several interventions have changed school food environments, for example, by reducing fat content of food in vending machines and making more fruits and vegetables available. Interventions are just beginning to target the availability of competitive foods. Other pressures can also compromise schools' efforts to encourage physical activity. As states use standardized tests to hold schools and students academically accountable, physical education and recess have become a lower priority. But some states are now mandating and promoting more physical activity in schools. School health services can also help address obesity by providing screening, health information, and referrals to students, especially low-income students, who are at high risk of obesity, tend to be underinsured, and may not receive health services elsewhere.