Do Sustainability Labels Lead to More Sustainable and Healthier Food Choices?
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Principal investigator:
Julia Wolfson
Johns Hopkins Bloomberg School of Public Health
Email: Jwolfso7@jhu.edu
Homepage:
https://publichealth.jhu.edu/faculty/4077/julia-wolfson
Sample size: 5055
Field period: 11/28/2021-04/27/2022
Abstract
In the United States (U.S), red meat consumption is consistently far above recommended levels based on national Dietary Guidelines, and red meat is a primary contributor to food systems related climate change. Fast-food restaurants could be a key environment for efforts to shift Americans towards more sustainable diets as Americans eat in fast-food restaurants frequently and several major chains have recently introduced meat-free/meat-alternative menu items. Sustainability menu labels are a potential tool to encourage more sustainable food choices, though much is unknown about potential effectiveness of such labels to nudge consumer behavior and possible ‘health halo’ effects they may confer. In this experimental study we tested whether sustainability labels on a fast-food restaurant menu nudge consumers towards more environmentally sustainable and/or healthier food choices by randomizing participants to three conditions: a fast-food menu with a red negative nudge label [HIGH CLIMATE IMPACT] displayed on high- greenhouse gas emission (GHGE) items, a menu with a green positive nudge label [LOW CLIMATE IMPACT] on low-GHGE items, or a control menu with a Quick Response (QR) code label on all menu items. We then assessed the effects of label condition on the sustainability and healthfulness of food selections.
Hypotheses
H1: Participants would be more likely to select sustainable options when viewing menus with positive or negative framing compared with control labels, but in the positive condition menu selections would not be healthier compared with other conditions.
H2: Participants exposed to positively framed labels would perceive their selected items to be healthier compared with individuals in the other conditions.
Experimental Manipulations
Participants (N=5,049) were randomly assigned to view a fast food menu with one of three label conditions: a quick response code label on all items (control group), a green low-climate impact label on chicken, fish or vegetarian items (positive framing), or a red high-climate impact label on red meat items (negative framing).
Outcomes
The main outcome was an indicator of selecting a sustainable item (i.e., one without red meat). Secondary outcomes included participants’ health perceptions of the selected item, and the Nutrition Profile Index (NPI) score of “healthfulness” Of the selected item.
Summary of Results
Both 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<0.001) selected a sustainable menu item when menus displayed high–climate impact labels and 9.9% more participants (95% CI, 1.0%-19.8%; P=0.03) 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<0.001; 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<0.001; 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< 0.001). 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<0.001) and control (52.9 [0.3] points; P<0.001) label groups. Overall, findings suggest that climate impact menu labels, especially negatively framed labels highlighting high–climate impact items (i.e., red meat), were an effective strategy to reduce red meat selections and encourage more sustainable choices.
References
Wolfson, J. A., et al. (2022). "Effect of Climate Change Impact Menu Labels on Fast Food Ordering Choices Among US Adults: A Randomized Clinical Trial." JAMA Network Open 5(12): e2248320-e2248320.