A systematic review and meta-analysis of the effectiveness of nudging to increase fruit and vegetable choice.

Background: Nudging refers to interventions that organize the choice architecture in order to alter people's behaviour in a predictable way without forbidding any options or significantly changing their economic incentives. As a strategy to encourage healthy behaviour, nudging can serve as a complement to health education. However, the empirical evidence regarding the effectiveness of nudging as a way to influence food choice remains contradictory. To address this issue, a systematic review and meta-analysis was conducted to test the effects of nudging to encourage people to select more fruit and vegetables.

Methods: A systematic literature search was performed on PubMed, Medline, PsycInfo, Cochrane library, Scopus and Google Scholar. After quality assessment, 20 articles (23 studies) were retained for narrative synthesis. Twelve articles (14 studies) contained enough information to calculate effect-sizes for meta-analysis using Comprehensive Meta-analysis software.

Results: The meta-analysis shows that nudging interventions that aim to increase fruit and/or vegetable choice/sales/servings have a moderately significant effect (d = 0.30), with the largest effect for altering placement (d = 0.39) and combined nudges (d = 0.28).

Conclusion: The results of this review provide an indication of the effectiveness of nudging on fruit and vegetable choice in terms of actual effect-sizes, while also highlighting the problems that must be addressed before more definitive conclusions can be drawn.