Importance: There is increasing interest in strategies to encourage more environmentally sustainable food choices in US restaurants through the use of menu labels that indicate an item's potential impact on the world's climate. Data are lacking on the ideal design of such labels to effectively encourage sustainable choices.
Objective: To test the effects of positive and negative climate impact menu labels on the environmental sustainability and healthfulness of food choices compared with a control label.
Design, setting, and participants: This randomized clinical trial used an online national US survey conducted March 30 to April 13, 2022, among a nationally representative sample of adults (aged ≥18 years) from the AmeriSpeak panel. Data were analyzed in June to October 2022.
Interventions: Participants were shown a fast food menu and prompted to select 1 item they would like to order for dinner. Participants were randomized to view menus with 1 of 3 label conditions: a quick response code label on all items (control group); green low-climate impact label on chicken, fish, or vegetarian items (positive framing); or red high-climate impact label on red meat items (negative framing).
Main outcomes and measures: The main outcome was an indicator of selecting a sustainable item (ie, one without red meat). Secondary outcomes included participant health perceptions of the selected item and the Nutrition Profile Index (NPI) score of healthfulness.
Results: Among 5049 participants (2444 female [51.6%]; 789 aged 18-29 years [20.3%], 1532 aged 30-44 years [25.9%], 1089 aged 45-59 years [23.5%], and 1639 aged ≥60 years [30.4%]; 142 Asian [5.3%], 611 Black [12.1%], and 3197 White [63.3%]; 866 Hispanic [17.2%]), high- and low-climate impact labels were effective at encouraging sustainable selections from the menu. Compared with participants in the control group, 23.5% more participants (95% CI, 13.7%-34.0%; P < .001) selected a sustainable menu item when menus displayed high-climate impact labels and 9.9% more participants (95% CI, 1.0%-19.8%; P = .03) selected a sustainable menu item when menus displayed low-climate impact labels. Across experimental conditions, participants who selected a sustainable item rated their order as healthier than those who selected an unsustainable item, according to mean perceived healthfulness score (control label: 3.4 points; 95% CI, 3.2-3.5 points vs 2.5 points; 95% CI, 2.4-2.6 points; P < .001; low-impact label: 3.7 points; 95% CI, 3.5-3.8 points vs 2.6 points; 95% CI, 2.5-2.7 points; P < .001; high-impact label: 3.5 points; 95% CI, 3.3-3.6 points vs 2.7 points; 95% CI, 2.6-2.9 points; P < .001). Participants in the high-climate impact label group selected healthier items according to mean (SE) NPI score (54.3 [0.2] points) compared with those in the low-climate impact (53.2 [0.2] points; P < .001) and control (52.9 [0.3] points; P < .001) label groups.
Conclusions and relevance: This randomized clinical trial's findings suggest that climate impact menu labels, especially negatively framed labels highlighting high-climate impact items (ie, red meat), were an effective strategy to reduce red meat selections and encourage more sustainable choices.
Trial registration: ClinicalTrials.gov Identifier: NCT05482204.