(P02-024-23) Greenhouse Gas Emission Menu Icons Reduce Demand for High-Emissions Menu Items at a Large, Public U.S. University

Objectives: To determine the impact of traffic-light style greenhouse gas (GHG) emission menu icons on the service of dishes with high amounts of embedded GHG emissions in all-you-care-to-eat university dining halls at a large, public U.S. university. We hypothesized that exposure to these icons would decrease demand for high-GHG emission dishes.

Methods: Three pairs of dining halls were matched based on patron volume and randomly assigned to a treatment status (intervention or control). Following a 4-week baseline period, pilot-tested GHG emission icons were applied to digital menus and point-of-service signs in intervention dining halls (with limited accompanying educational materials) for 10 weeks beginning January 2022. The dataFIELD emissions database was used to calculate the GHG emissions for every ingredient in the university dining service’s database, and in turn, to assess the total emissions of each recipe. Menus were matched as closely as possible within matched dining hall pairs. A difference-in-difference estimator using a GLM model with a gamma distribution, log link function, and robust variance estimator was used to assess differences in the amount of high-GHG emission dishes served per person in control dining halls pre- to post-intervention start minus this difference in intervention dining halls.

Results: Preliminary analyses indicate that among one dining hall pair, the two largest dining halls, there was a statistically significant downward trend (pre- to post-intervention start) in g served per person of high-GHG emission dishes at the intervention dining hall relative to the control dining hall (P < 0.05). The intervention hall demonstrated a 38% reduction in the service of high-GHG emission dishes relative to the control hall. A statistically significant difference-in-difference estimate in service of high-GHGE emission dishes was not observed for the other two dining hall pairs.

Conclusions: GHG emission menu icons may dissuade young adults from selecting high-GHG emission items within all-you-care-eat U.S. university dining halls. However, menu icons may need to be combined with behavior change communication efforts to yield substantive and sustained behavior change.

Funding Sources: Graham Sustainability Institute of the University of Michigan