Ecolabels and the Healthfulness and Carbon Footprint of Restaurant Meal Selections: A Randomized Clinical Trial.

Importance: Restaurants are increasingly interested in capitalizing on consumer interest in environmental sustainability by marketing their products with ecolabels, which signal when foods are more environmentally sustainable. Ecolabels could improve the healthfulness of restaurant meal selections and reduce their carbon footprint, but this potential remains largely untested. Objective: To test whether displaying ecolabels on restaurant menus improves the healthfulness and reduces the carbon footprint of restaurant meal selections. Design, Setting, and Participants: This randomized clinical trial was conducted online in September to October 2024. A national sample of US adults (aged ≥18 years) was recruited. Participants were randomly assigned to the ecolabel or control arm. Participants viewed a restaurant menu mimicking a popular full-service restaurant and selected items they wanted to order. Statistical analyses were based on the intention-to-treat principle. Interventions: In the ecolabel arm, participants viewed a menu that displayed ecolabels next to entrées and appetizers with a lower carbon footprint (ie, below the median of 1.625 kg of carbon dioxide equivalent [CO2e] emissions per item). In the control arm, participants viewed a menu that did not display ecolabels. Main Outcomes and Measures: The outcomes included overall healthfulness (assessed using Ofcom Nutrient Profiling Model scores; range: 0-100, with higher scores indicating healthier items), nutrient content, and total carbon footprint of participants' entrée and appetizer selections and entire orders (including beverages and desserts). Results: A total of 3147 participants completed the online trial (1560 men [50%]; mean [SD] age, 34.5 [12.5] years). Participants in the ecolabel arm did not select entrées and appetizers (average differential effect [ADE], 0.45 [95% CI, -0.18 to 1.09]; P = .16; Cohen d = 0.05) or entire orders (ADE, 0.47 [95% CI, -0.09 to 1.03]; P = .10; Cohen d = 0.06) that were statistically significantly healthier compared with the selections of participants in the control arm. Participants in the ecolabel arm selected entrées and appetizers (ADE, 0.87 [95% CI, 0.12-1.62] g; P = .02; Cohen d = 0.08) and entire orders (ADE, 0.82 [95% CI, 0.07-1.56] g; P = .03; Cohen d = 0.08) with more fiber, compared with the selections of participants in the control arm, but did not select entrées and appetizers or entire orders with statistically significantly different amounts of protein, sugar, saturated fat, or calorie content. Participants in the ecolabel arm selected entrées and appetizers (ADE, -0.78 [95% CI, -1.25 to -0.32] kg of CO2e emissions; P < .001; Cohen d = -0.12) and entire orders (ADE, -0.81 [95% CI, -1.27 to -0.34] kg of CO2e emissions; P < .001; Cohen d = -0.12) with lower carbon footprints than the selections of participants in the control arm. Conclusions and Relevance: In this randomized clinical trial, menu ecolabels reduced the carbon footprint of restaurant meal selections without worsening nutritional quality. Ecolabels could be a scalable, low-cost strategy to reduce the carbon emissions of restaurant food choices. Trial Registration: ClinicalTrials.gov Identifier: NCT06584539.