Meat-heavy diets threaten not only our health but also the health of the planet, as large-scale animal husbandry destroys habitat and produces greenhouse gases.
Conservationists at the University of Cambridge are investigating ways to “lure” people towards eating more plants and less meat, to help prevent environmental damage from overconsumption of animal products.
Researchers tested customers in two Cambridge college cafeterias to see if the presence of vegetarian options affected plant-based food intake.
They collected and analyzed data from 105,143 meal choices over a two-year period, alternating meat and vegetarian meals each week and then changing the pattern each month.
The size of the study is unprecedented. A previous review of various studies using “choice architecture” to reduce meat consumption only reached a combined 11,290 observations.
The researchers found that placing veggies before meat in the order of meal options, such as entering the serving area, did little to encourage green eating at one of the colleges.
At other colleges, however, sales of plant-based foods increased by a quarter (25.2%) on a weekly basis and nearly 40% (39.6) on a monthly basis.
Difference: About one meter of added distance between vegetarian and meat options, 85 cm gap in first college compared to 181 cm gap in second college. The findings are published today in the journal Nature Food.
“Reducing meat and dairy consumption is one of the easiest and most impactful choices to make to protect the climate, the environment and other species,” said study lead author Emma Garnett, a conservationist in Cambridge’s Department of Zoology.
“We need to make better choices for people. We hope to see these results used by catering managers and indeed anyone interested in cafeteria and menu design to promote more climate-friendly food.”
The latest research follows on from work by Garnett and colleagues published last fall, which showed that adding additional veggie options to cafeterias reduced meat consumption without bumping up overall sales.
Livestock and aquaculture account for about 58% of global food-generated greenhouse gases, behind meat, fish, dairy and eggs, and occupy 83% of agricultural land despite contributing only 18% of the world’s caloric intake.
Recently, Cambridge researchers recommended eating less meat to reduce the risk of future pandemics, and UK public sector caterers pledged to cut the amount of meat used in schools and hospitals by 20%.
Experiments were conducted across two colleges — one with 600 students and one with 900 students — where cafeteria customers were presented with vegetarian and meat options in varying orders for weekday lunch and dinner.
College members pick up a tray, look at the food on offer and then ask the serving staff to make options of their choice. Meals are purchased by swiping the university’s card, and the researchers only collected anonymized data on main meal selections (sandwiches and salads were not counted).
Although the catering managers helped set up the tests, the diners were unaware.
The researchers expected to see a difference in vegetarian sales by ordering only, but it was only in colleges with extra meters — a gap of 181 cm — between meal options that recorded an increase when ordering “veg first.”
To confirm the results, the researchers reduced the gap to only 67 cm in this cafeteria and sales of vegetarians decreased sharply. In fact, at such a short interval, vegetarian foods fared worse when placed first (down about 30% compared to “meat first” days).
“We think the meter’s effect may be less on the extra effort required to find meat. If the first bite is eye-catching, many people seem perfectly happy with an appetizing veggie option when meat is hard to find,” Garnett said.
“All cafeterias and restaurants have a design that ‘nudges’ people towards something. So it’s wise to use a design that makes it easiest to choose the healthiest and most sustainable food options without thinking,” he says.
“We know that information alone is usually not enough to change our harmful habits. We need more research on how to set up society so that the self-interested default decision is best for the climate.”
Garnett’s research has contributed to food policy at the University of Cambridge, where catering services have worked to reduce the amount of meat they use.
Last year, university cafeterias (separate from colleges) announced a 33% reduction in carbon emissions per kilogram of food purchased and a 28% reduction in land use per kilogram of food purchased.