Residents of high-income countries consume the most animal products—which are responsible for 15% of all human-generated greenhouse gases—and as a result, their diets are in greatest conflict with greenhouse gas reduction targets. Further, the farming of meat, eggs, dairy, and fish requires approximately 83% of available land, despite accounting for just 18% and 37% of our calories and protein, respectively.
To promote healthier diets for individuals and the environment, researchers in a new study wanted to know if simply increasing the availability of vegetarian options could also increase their consumption.
In three cafeterias at the University of Cambridge, the proportion of vegetarian meals available was increased from 1-in-4 to 2-in-4. In other words, vegetarian meals were no longer treated as a menu afterthought.
That said, this study suggests vegetarian nudges could help even the most fervent carnivores achieve a more balanced, sustainable diet and at the same time make another small push against climate change.
By modifying the cafeteria’s menu, researchers changed the context of the individual diner’s food decision. Such adjustments, known as nudges, preserve freedom of choice and instead suggest a new, desirable alternative. For diets, this concept has encouraged healthier choices by decreasing high-calorie meal options.
After increasing the number of vegetarian options, they found diners who previously bought more meat entrees ate more vegetarian meals after the adjustment. Across 94,644 purchases, vegetarian meal sales rose between 41% and 79%.
Vegetarian purchases did not decrease at dinner, meaning veggie consumers at lunch did not necessarily compensate by eating meat at dinner. Additionally, the change had no impact on sales, a positive sign for cafeteria managers.
More research is needed to fully assess the effect of availability changes on diets, especially in other settings like restaurants. That said, this study suggests vegetarian nudges could help even the most fervent carnivores achieve a more balanced, sustainable diet and at the same time make another small push against climate change.