The impact of autonomy-framed and control-framed implementation intentions on snacking behaviour: the moderating effect of eating self-efficacy

Background Autonomy‐supportive implementation intention exercises have been shown to facilitate goal‐directed behaviour (Koestner et al., 2006). The current study explored whether eating self‐efficacy moderated the impact of autonomy‐framed versus control‐framed implementation intentions to reduce high‐calorie snack intake. Methods The study employed a randomised prospective design, involving two waves of data collection conducted in 2016. At Time 1, UK participants (N = 300) completed an online questionnaire which asked them to report their snacking behaviour over the previous 7 days. Participants were subsequently asked to form either an autonomy‐framed implementation intention or a control‐framed implementation intention. Seven days later, participants reported their consumption of high‐calorie snacks and completed a measure of eating self‐efficacy. Results Hierarchical multiple regression analysis revealed that eating self‐efficacy moderated the effects of implementation intention framing. Autonomy‐framed implementation intentions had a greater impact on the avoidance of snacking for high eating self‐efficacy participants than did control‐framed implementation intentions. In contrast, for low eating self‐efficacy participants, control‐framed implementation intentions had more impact than did autonomy‐framed implementation intentions. Conclusions The results suggest that if implementation intentions to promote healthy diet are to be effective, the role of eating self‐efficacy should be considered, and the design of interventions adapted accordingly.