Environmental Impact of Food Items on the Menu

Ordering a hamburger might soon come with more than a calorie count. Food systems account for about one-third of global greenhouse gas emissions, and some foods have larger environmental footprints than others. Some restaurants are beginning to display the environmental impact of food items on their menus. A new study led by researchers at the University of California, Davis, shows that climate labels can nudge people toward more environmentally friendly food choices.

Allie Reimold, a postdoctoral scholar with the Department of Human Ecology, led an online randomized clinical trial to compare the effects of a variety of climate label designs.

While some people may not think about greenhouse gas emissions when ordering lunch, Reimold said food choices can have a meaningful impact on the environment.

“Many consumers want to know how to reduce their climate impact, and these labels can help them make informed decisions,” Reimold said.

Testing different labels

In collaboration with the World Resources Institute and researchers at Johns Hopkins University, the team calculated greenhouse gas emissions for popular fast-food menu items. More than 10,000 participants viewed a realistic fast-food menu featuring these items with different climate labels applied to them. The study shows participants who viewed menus with “High Climate Impact” and “Climate Grade” labels were less likely to select items with high climate impacts. The "Climate Grade" label gave each menu item a letter grade from A (low climate impact) to F (high climate impact) and showed the full A-to-F scale on the label. Reimold said participants who saw this label selected menu items with lower greenhouse gas emissions, as well as fewer calories, less sodium and less saturated fat.

Researchers also tested a novel "Environmental Cost" label that put a dollar value on the greenhouse gas emissions associated with producing a menu item, such as a hamburger or garden salad. Reimold said participants generally viewed this label as effective, but it did not lead people to choose significantly healthier or lower-climate-impact menu items.

Currently there are no mandates in the United States for restaurants to include climate labels on menus, but some eateries have adopted them voluntarily. Similar environmental labeling systems, such as France's Eco-score, are also being used in other countries.

Reimold said the next question is which label designs work best in real-world restaurant settings.

“Although some restaurants are voluntarily implementing climate labels, they probably don’t know the best design for actually helping consumers,” Reimold said. “Overall, climate labels that provide clear information and are quick and easy to understand are going to be the most effective.”

This project was funded in part by grants from the American Diabetes Association and the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases. The senior author is Jennifer Falbe with UC Davis, and other co-authors are Brittany Lemmon with UC Davis and researchers from Johns Hopkins Bloomberg School of Public Health, Harvard T.H. Chan School of Public Health and World Resources Institute.