Can Social Norms Promote Sustainable Food Consumption? A Systematic Review

As societies transition towards a reduction of meat consumption and a shift to plant-based diets to address sustainability challenges, several studies highlight the importance of social norm interventions in promoting sustainable food choices. Nonetheless, syntheses of research on the effectiveness of such interventions are currently lacking, hampering our ability to inform and propose new research directions to increase sustainability in real-world contexts. In this paper, we review and evaluate the current body of evidence, focusing on studies targeting a reduction in animal-based food consumption and/or an increase in plant-based consumption, and specifically motivated as contributing to the climate change discourse. We searched five databases, theses repositories, and grey literature and contacted authors in the field to obtain manuscripts and pre-prints. Our search identified 23 articles including 34 separate studies meeting our eligibility criteria. Since 2017, we witnessed a rapid increase in research interest for trials exploring the effect of social norms to nudge individuals towards sustainable food choices. Overall, based on the results of this review, we conclude these interventions have had limited success and we identify opportunities for future research on this topic, such as identifying the most relevant referent group for various segments of the population.