Nudging greater vegetable intake and less food waste: A field experiment

Abstract

Diet change and food waste reduction are key levers for meeting climate change goals, but little is known about pursuing policies to shape both behaviors simultaneously. In a between-subjects field experiment, we randomly assign distinct cognitive and behavioral nudges focused on increasing vegetable consumption and decreasing food waste among foodservice consumers. The individual and joint efficacy of nudges in changing the intake and waste of each meal component is measured by scale. We find increases in both vegetable consumption (effect size = 0.90) and wasted food (effect size = 0.96) among participants randomly assigned to meals with 50 % (vs 25 %) of the plate covered with vegetables (behavioral nudge). Information about the social costs of food waste (cognitive nudge) mitigated the increase in waste induced by the 50 % vegetable nudge by encouraging greater vegetable intake. However, these mitigation effects disappeared if participants also received information (a second cognitive nudge) recommending increased vegetable consumption to improve health. Displaying meals on a larger plate (behavioral nudge) significantly increased selection of larger portion sizes, which led to greater vegetable intake but no change in waste. These results highlight the need to understand interactions between nudges when pursuing policies to accomplish multiple behavioral changes in foodservice settings.