Using the Default Nudge to Increase Plant-based Meal Consumption on College Campuses

Abstract

ObjectivesClimate, environmental, and nutrition scientists have recommended reduced meat and dairy consumption as key to reducing adverse planetary and human health impacts. We conducted this study to (1) investigate the effect of a default plant-based nudge on participant meal choices at a higher education institution and (2) to project the footprints of these choices: greenhouse gas (GHG) emissions (g CO2-eq), blue water (m3), land use (m2), nitrogen (g N), and phosphorus (g P) usage. MethodsData collection was performed at two student events where catering was provided. We used a randomized controlled trial (RCT) design to determine if students presented with a plant-based meal as the default option were less likely to choose a meat option. At each event, students were randomly assigned to two groups. The control group received a RSVP form that presented a meal with meat as the default option. The intervention group received a form that presented a plant-based meal as the default. To project and compare the environmental impacts of each group, we modeled two plant-based and two meals with meat. Using these meals we calculated the footprints of two 100-person events based on the RCT meal selections. ResultsWe observed a large effect size (p < 0.0001) across both experiments. In the first event (n = 108) the intervention decreased the selection of meat meals by 43 percentage points (85% to 42%). In the second event (n = 81) the intervention decreased meat meal selection by 56 percentage points (83% to 27%). When comparing the projected 100-person events based on the RCT meal selections, we found reductions in GHG emissions (28–59%), land use (24–59%), nitrogen (40–57%), and phosphorus (37–61%) footprints. However, we also found an increase in blue water usage (41–77%). ConclusionsThis intervention is a low-effort, high impact way to decrease the share of meals containing meat in institutional settings. Adopting a default plant-based policy may be an effective way to reduce environmental impact and encourage healthier options while maintaining choice. Funding SourcesBetter Food Foundation, National Science Foundation.