We examine the effect of the School Breakfast Program (SBP) availability with the National Health and Nutritional Examination Survey III. Our work builds on previous research by developing a transparent difference-in-differences strategy to account for unobserved differences between students with access to SBP and those without, using serum measures in addition to intake measures to assess the potential program effects, and examining program effects on other household members. Our results suggest that the SBP program improves the nutritional outcomes of the direct recipient across a wide array of different measures. Our results indicate fewer positive effects for other household members.