Background: The reinforcing value of food and access to cognitively enriching activities are prospectively related to relative weight in children. Energy intake represents a choice between eating or engaging in alternative, non-eating activities, however, no research has yet assessed the combination of the motivation to eat, as indexed by food reinforcement, and access to activities that can serve as alternatives to eating, or the access to food. Methods: To address this research gap, we studied the relationship between these variables and change in percent overweight over two years in 291 6-9 year-old children of varying baseline percent overweight and socioeconomic status. Food reinforcement was measured using a behavioral reinforcing value task and enriched environment was measured using the Home Observation for Measurement of the Environment interview in familys homes. Results: Mixed effect regression analysis showed that change in percent overweight was predicted by the interaction of reinforcing value of food and the home environment (beta = 0.018, p = 0.048). Children who were low in food reinforcement and lived in an enriched environment showed no increase in percent overweight, while those high in food reinforcement who lived in a relatively non-enriched showed the greatest increase in percent overweight. Conclusions: These results suggest that providing an enriched home environment may reduce the effects of food reinforcement on weight gain in childhood, and this represents a novel approach to intervention that can be used strengthen current behavioral approaches to prevent obesity in children.