Over the last two decades the proportion of adolescents in the United States who are obese has nearly tripled, and schools, citing financial pressures, have given students greater access to "junk" foods, using the proceeds to fund school programs. We examine whether schools under financial pressure tend to adopt potentially unhealthful food policies and whether students' Body Mass Index (BMI) is higher where they are more likely to be exposed to these food policies. We find that a 10 percentage point increase in potential exposure to junk food in schools leads to about a 1 percent increase in students' BMI.