Livestock production contributes an estimated 14.5% of human-induced global greenhouse-gas emissions, contributing to global warming, as well as leading to degraded ecosystems, biodiversity and water resources.
In 2019, 37 researchers from 16 countries published the Eat-Lancet report, which supports the global adoption of a mainly plant-based diet, with significant reductions in consumption of animal products such as meat and dairy. The first advisory report from the UK’s Committee on Climate Change in 2020 also reflects these findings, advocating that beef consumption must be considerably reduced if the UK is to reach its net-zero greenhouse-gas emission target by 2050.
One way to promote a more sustainable diet is to label food products with information about sustainability (eco-labelling), for example by providing details of water and land usage, as well as greenhouse-gas emissions, using a traffic light system. Another option is the use of social nudging, such as telling consumers that a particular menu option is the most popular choice.
Our study aimed to investigate how an eco-label and a social nudge label influenced food choice compared to a control group with no label. The secondary aim was to investigate whether an individual’s motivation to act sustainably influenced the efficacies of the labels.
We conducted this study online, with UK adults who were 18 years or older. These people were randomised to one of three different groups. In each group the person was shown a menu containing three different meal options (a beef burrito, a chicken burrito or a vegetarian burrito) and asked to (hypothetically) choose one option they might like to eat in the future. In all three study groups the menus appeared the same except for these differences:
1. Group one were shown the burrito options accompanied with an eco-label showing the sustainability level of each meal in a traffic light system (beef burrito – red [unsustainable], chicken burrito – amber [neither sustainable nor unsustainable], and vegetarian burrito – green [sustainable]).
2. Group two were shown the vegetarian burrito presented alongside a popularity label consisting of a gold star next to the words “Most Popular”, with the other two burritos having no label.
3. Group three was the control group and these participants were shown neither the eco-label nor the social nudge (i.e., all three burritos had no label).
We found that both the eco-label and social nudge label were effective at influencing choices towards more sustainable foods. There was evidence that more vegetarian and chicken burrito choices were made in the eco-label group compared to the control group. In the social nudge group, there was also evidence that participants chose a vegetarian burrito over a beef burrito, but this label did not encourage participants to choose a vegetarian burrito over a chicken burrito. Although both labels were effective at promoting more sustainable food choices, the eco-label was the most effective in this goal.
Participants with a higher motivation to act sustainably were more likely to choose a vegetarian burrito over a beef or chicken burrito in all three study groups. however, this effect was greatest in the eco-label group (where participants were given information about the sustainability of the burritos).
Pending replication in real-world settings (rather than online), our study suggests that future policy could include eco-labelling and / or a social nudge in both real-world and on-line settings to reduce meat consumption and meet global climate change targets.