When planning is not enough: the self-regulatory effect of implementation intentions on changing snacking habits.

Objective: This study examined whether matching implementation intentions to people's regulatory orientation affects the effectiveness of changing unhealthy snacking habits.

Design: Participants' regulatory orientation was either measured (as a chronic trait) or manipulated (as a situational state), and participants were randomly assigned to implementation intention conditions to eat more healthy snacks or avoid eating unhealthy ones.

Main Outcome Measures: A self-reported online food diary of healthy and unhealthy snacks over a 2-day period.

Results: Participants with weak unhealthy snacking habits consumed more healthy snacks when forming any type of implementation intentions (regardless of match or mismatch with their regulatory orientation), while participants with strong unhealthy snacking habits consumed more healthy snacks only when forming implementation intentions that matched their regulatory orientations.

Conclusion: RESULTS suggest that implementation intentions that match regulatory orientation heighten motivation intensity and put snacking under intentional control for people with strong unhealthy snacking habits.