Objective: The present study aimed to advance our understanding of health-related theory, that is, the alleged intention-behavior gap in an obese population. It examined the mediating effects of planning on the intention-behavior relationship and the moderated mediation effects of age, self-efficacy and intentions within this relationship.
Method: The study was conducted over a five-week period. Complete data from 571 obese participants were analyzed. The moderated mediation hypothesis was conducted using multiple-regression analysis. To test our theoretical model, intentions (Week 2), action self-efficacy (Week 2), maintenance self-efficacy (Week 5), planning (Week 5), and saturated-fat intake (Weeks 1 and 5) were measured by self-report.
Results: As hypothesized, planning mediated the intention-behavior relationship for perceived (two-item scale) and percentage-saturated-fat intake (measured by a food frequency questionnaire). Age, self-efficacy, and intention acted as moderators in the above mediation analysis. In specific, younger individuals, those with stronger intention, and people with higher levels of maintenance self-efficacy at higher levels of planning showed greater reductions in their perceived saturated-fat intake.
Conclusions: For successful behavior change, knowledge of its mediators and moderators is needed. Future interventions targeting planning to change saturated-fat intake should be guided by people's intentions, age, and self-efficacy levels.