A systematic review and meta-analysis on the effectiveness of if-then plans - in a strict sense - to facilitate fruit and vegetable consumption in adults.
A systematic review and meta-analysis on the effectiveness of if-then plans - in a strict sense - to facilitate fruit and vegetable consumption in adults.: A fruit-and-vegetable rich diet is important in the prevention of non-communicable diseases. If-then plans, or implementation intentions, are proposed to facilitate behavior change by formulating plans that link perceivable cues and goal-directed responses. We investigated the effectiveness of if-then planning interventions to facilitate fruit and vegetable intake in adults, with a strict focus on if-then planning procedures and excluded procedures representing conventional planning. A systematic review (MEDLINE, Embase, and PsycInfo; last searched April 3rd, 2025) and meta-analysis was conducted. Included studies were randomized controlled trials, testing the effect of if-then plans on fruit and/or vegetable intake against active control groups. Ten articles were identified as eligible, including 12 comparisons (N = 2399) with intervention-outcome periods of 1 week to 24 months. If-then planning participants reported consuming approximately a quarter of a portion of fruit and vegetable per day more than participants in the control groups (MD = 0.29, 95% CI: 0.11; 0.48). A central limitation of the analysis is that all included studies are based on self-reported fruit and vegetable consumption. While the effect size of the investigated intervention is small, its low resource requirements make it an accessible option for promoting fruit and vegetable consumption. Evidenzgrad A, Risk of Bias unclear.