Background: Access to sufficient food--in terms of both quality and quantity--is especially critical for children. Undernourishment during childhood and adolescence can have health implications, both short and long term. The prevalence of food insecurity was assessed in a sample of Vermont school children, as well as the relationship between food insecurity, participation in school breakfast or lunch, exercise and body mass index (BMI), all with a goal to identify needs to improve effectiveness of current programs. Methods: A cross-sectional, 23-item self-administered survey of students attending a public middle school in Vermont. Results: Twenty percent of the children were residing in a food insecure household. No statistically significant differences were observed in terms of age, sex or BMI percentile and food security status. Food insecure (with or without hunger) participants were less likely to eat breakfast at home compared to food secure participants (67.1% vs 81.4%, p = 0.007). However, such differences were not observed between eating school breakfast or lunch. Sixty-two percent of food insecure (with or without hunger) participants engaged in daily exercise compared to 75.9% food secure participants (p = 0.014). Conclusion: Children in food insecure households were less likely to be physically active and to eat breakfast at home. However, the school breakfast program is negating any difference between the 2 groups in terms of eating breakfast at all. We consider this a success given the short- and long-term implications of food insecurity in children. We believe these findings have important implications for schools, policy makers, and programs to reduce food insecurity. (Contains 1 table.)