This study used one weekday and one weekend day of dietary recall data for 2,376 school children in NHANES (2003-2008) to address two related objectives: (1) to estimate relationships between school meals participation and weekday dietary intake, controlling for weekend dietary intake as a proxy for food preferences and health beliefs; and (2) to estimate the prevalence of low energy intake and low dietary quality on the weekend, and investigate their associations with household resources and school meals participation. The analysis provided no evidence that a lack of school meals on the weekend adversely affects dietary intake among school children. Low energy intake and low dietary quality were equally prevalent on weekdays and weekend days, and both were unrelated to measures of household resources and school meals participation. We also found that school meals participants and non-participants had equivalent energy intake and overall dietary quality. Low-income children who participated in both SBP and NSLP had significantly higher overall quality, and for grains, meat and beans; while participants from higher income families had significantly lower scores for grains and saturated fat.