The community food environment moderates the relationship between active commuting to school and child weight status.

Objectives: Children who walk or bike to school engage in higher levels of physical activity compared to non-active commuters. However, despite the established benefits of increased physical activity, the observed association between active commuting to school (ACS) and child body mass index has been mixed, possibly due to obesogenic food environments to which some children may be exposed along the route between home and school. Our aim was to examine whether the food environment surrounding children's homes moderated the association between ACS and child body mass index z-scores (zBMI). Methods: We conducted multivariable regression analyses utilizing cross-sectional data from a household survey distributed in 2014 within four low-income cities in New Jersey (n = 627). We used geocoded addresses for the child's home and for food outlets (i.e., limited-service [fast food] restaurants, convenience stores, small grocery stores, and supermarkets) to characterize the food environment within 0.25 miles of the child's home. Results: Among active commuters, a larger number of convenience stores and fast-food restaurants and the presence of at least one small grocery store near home were associated with higher zBMI; there was no such association among children who were not active commuters to school. Correspondingly, ACS was associated with lower zBMI among active commuters, but only within less unhealthy food environments. Conclusions: Findings suggest that unhealthy food environments have the potential to impede the beneficial association between ACS and child weight. Policy and intervention efforts to support ACS should also encourage the availability and promotion of healthy foods in food outlets frequented by children.