Environmental Harm Menu Labels and Overall Dietary Quality (MENU)

Participants order one lunch per week for seven weeks from two alternating fast-food restaurant menus. The Week 1 menu is unlabeled. In Weeks 2-7, a control label consisting of a QR code is applied to all main items on the restaurant menus. Participants in this arm are randomized in equal numbers to begin with the burger restaurant menu or the sandwich restaurant menu in Week 1; the two restaurants then alternate weekly, so that each participant sees their first restaurant in Weeks 1, 3, 5 and 7 and the other restaurant in Weeks 2, 4 and 6.

A control label consisting of a QR code is applied to the main items on both restaurant menus in Weeks 2-7. The label carries no environmental information.

Participants order one lunch per week for seven weeks from two alternating fast-food restaurant menus. The Week 1 menu is unlabeled. In Weeks 2-7, traffic-light style environmental harm labels are applied to all main items on the restaurant menus. Participants in this arm are randomized in equal numbers to begin with the burger restaurant menu or the sandwich restaurant menu in Week 1; the two restaurants then alternate weekly, so that each participant sees their first restaurant in Weeks 1, 3, 5 and 7 and the other restaurant in Weeks 2, 4 and 6.

Traffic-light style environmental harm labels are applied to the main items on both restaurant menus in Weeks 2-7. Each label conveys the environmental harm of the item, defined for participants as how much water and land are required to produce it. Harm levels are assigned from ingredient-level land use and water use factors applied to the ingredients of each menu item.

Dietary quality is measured with the Healthy Eating Index-2020 (HEI-2020), calculated from mean intake across two 24-hour dietary recalls administered at each timepoint by trained staff of the Johns Hopkins ICTR Nutrition Core. HEI-2020 is a composite measure of dietary quality scored from 0 to 100, based on 13 components: nine adequacy components (e.g., whole grains, total vegetables, seafood and plant proteins) and four moderation components (e.g., refined grains, sodium, added sugars). A higher score indicates better diet quality and closer alignment with the 2020-2025 Dietary Guidelines for Americans.

Adequacy scores range from 0-5 (total fruits, whole fruits, total vegetables, greens and beans, total protein foods, seafood and plant proteins). Moderation scores range from 0-10 (whole grains, dairy, fatty acids, refined grains, sodium, added sugars, saturated fats). Higher scores indicate healthier intake (higher intake for adequacy components and lower intake for moderation components).

Total fruit (including 100% fruit juice) intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total whole fruit (excluding 100% fruit juice) intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total vegetable intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total intake of greens and beans in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total whole grain intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total dairy intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total protein food (including legumes) intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total seafood and plant protein (including nuts, seeds, soy products, legumes) intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each time point.

Ratio of fatty acids (PUFA + MUFA)/ SFA, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total refined grain intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total sodium intake in milligrams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total added sugar intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Total saturated fat intake in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Beef consumption in grams per day, derived from the mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline. A decrease indicates reduced beef consumption.

Total energy intake in kilocalories per day, derived from mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.

Fiber intake in grams per day, derived from mean intake across the two 24-hour dietary recalls at each timepoint. The outcome is the difference between endline and baseline.