The theory of planned behavior and healthy eating.

Application of the theory of planned behavior (TPB) to healthy eating in 144 health promotion clinic attendees is reported. Respondents completed self-report TPB measures after the clinic (Time 1) and 6 months later (Time 2) with a measure of perceived past behavior. Intention stability was assessed on Time 1-2 differences. Six years later (Time 3), respondents completed measures of healthy eating intentions and behavior. Intentions were predicted by attitudes, perceived behavioral control, and perceived past behavior (cross-sectionally). Healthy eating behavior (Time 3) was predicted from intentions (Time 2). As intention stability increased, intentions and perceived past behavior became stronger and weaker predictors of behavior, respectively. Implications for understanding health cognitions in long-term performance of health behavior are discussed.