Climate Impact Label Design and Fast-Food Meal Selection

This online randomized trial will test the relative effects of climate impact menu label designs on the healthfulness of consumers' fast-food meal choices and perceptions of menu items. The survey research firm CloudResearch will recruit a sample of 6,250 adults aged 18 years and older who speak English and reside in the United States. Participants will complete a between-subjects online experiment in which the participants will be randomized to view a fast-food online ordering menu with one of five labeling schemes applied: (1) a QR code on all items (control); (2) a high climate impact warning label on high impact items; (3) traffic light labels on all items by level of impact; (4) climate grade labels on all items by level of impact; and (5) numeric carbon footprint labels on all items. All fast-food menus will include main items, sides, desserts, and drinks. Labels will only appear alongside main menu items and will be assigned using thresholds for greenhouse gas emissions set a priori in kilograms of carbon dioxide (CO2) equivalent per kilogram of food. Participants will be instructed to select up to 4 menu items for a hypothetical meal order. After completing the meal ordering task, participants will be prompted to answer questions about the perception of the labeling condition which the participants were randomized to view, perception of the relative effectiveness of all labels in this experiment, and personal values, dietary patterns, and other demographic information. The primary outcome will be the healthfulness of meal orders selected from the online menu, indicated by a modified Nutrient Profile Index meal score for all food items ordered. Secondary outcomes will be total greenhouse gas emissions per meal ordered, total calories ordered, whether a sugar-sweetened beverage was ordered, and perceived message effectiveness of the climate-impact labels.