This paper discusses the results of a study that tested whether the associations between franchised fast-food restaurants or convenience store density near schools and childhood overweight varied by race/ethnicity, sex, and grade. Using data for 926,018 racially/ethnically diverse children in fifth, seventh, or ninth grade in 6,362 public California schools, researchers documented four findings in this study: 1) after controlling for student and school characteristics, fast-food restaurant density around schools was significantly related to overweight prevalence in the overall sample; 2) fast-food restaurant density was associated with higher overweight prevalence among Hispanics and Blacks but lower prevalence among Asians; 3) greater convenience store density was associated with overweight prevalence in the overall sample; and 4) some evidence suggests that the food environment may have a stronger influence among younger children and girls.