Effectiveness of nudge interventions to promote fruit and vegetables' selection, purchase, or consumption: A systematic review

This study assessed the effectiveness of nudge interventions aiming to increase the selection, purchase, or consumption of fruit and vegetables (F&V) in real-life settings. The review searched three databases (Pubmed, Scopus and Web of Science) covering the period from 2008 to October 2022. Interventions were classified as either single or multi -stranded, based on the use of one, or two or more typologies, respectively. An effectiveness score was assigned to interventions: -1 for ineffective, 0.5 for partially effective, 1 for totally effective. Overall, 81 % of the interventions were effective (partially or totally). Regarding single -stranded interventions, informative and positional interventions had the highest scores of 9 and 5.5, respectively (in a range from 0.5 to 9). These remained the most effective typologies when both single and multi -stranded interventions were assessed with scores of 14 and 13.5 to position and information, respectively (in a range from -0.5 to 14). The most effective and studied strategies within these typologies involved altering the salience and accessibility and providing information using health claims, social norms, or labels/symbols. Interventions aiming to increase F&V purchases (score of 13.5, in a range from 6.5 to 13.5), conducted with adults (score of 21.5, in a range from 2.5 to 21.5) or tested for short periods (<= 1 week) (score of 11.5, in a range from -0.5 to 11.5) were the most effective. Some results differed when adjusting to the total number of assessment moments. Nudging interventions are effective in promoting the selection, purchase, and consumption of F&V in real-life settings.