Executive function moderates the intention-behavior link for physical activity and dietary behavior.

Dominant theories of health behavior posit that social-cognitive and conative variables are sufficient to explain health behavior tendencies. The current studies challenge this assumption in two ways: (1) by demonstrating that unique variance in health protective behavior is predictable by knowing about individual differences in executive functioning, and (2) by demonstrating that executive function moderates the association between intention and behavior. In Studies 1 and 2, participants completed a computer-based task of executive function (Go/NoGo task) and articulated 1-week behavioral intentions for physical activity (Study 1) and dietary behavior (Study 2). Hierarchical regression analyses revealed that executive function predicts unique variance in both behaviors, and strongly moderates the association between behavioral intention and behavioral performance. Together behavioral intention and executive function explain more variance in health protective behavior than 'rational actor' models that have been widely adopted and disseminated.