This study uses data from the Early Childhood Longitudinal Survey, Kindergarten Class of 1998 to explore the impact of food insecurity, school environment and food infrastructure on elementary school-aged children’s body weight, food purchasing decisions and physical activity choices. Results show that Federal support for nutrition in the form of expenditures, a lower county unemployment rate, higher average wages, and access to unemployment compensation are associated with a lower risk of being food insecure. Using longitudinal methods, the study finds a positive association between household food insecurity and child BMI, but the connection is not consistent across gender and racial groups.