University of Cambridge researchers discover how to nudge us towards vegetarian options in a cafeteria
An extraordinary study of more than 105,000 meal choices at two University of Cambridge colleges has found a simple way to ‘nudge’ diners in cafeterias towards more planet-friendly vegetarian choices over meat dishes.
Researchers have found that a kind of social distancing between the options makes a substantial difference to the uptake of plant-based food.
In one college, vegetarian dishes were placed before the meat options for those entering the serving area. In this case, it did little to bolster ‘green’ eating.
In the other college, the meat dishes were put much further away from the vegetarian choices - a gap of 181cm, compared to 85cm at the first college. Here, sales of plant-based dishes shot up by 25.2 per cent in a week - and by 39.6 per cent in a month.
Catering managers helped to set the ‘choice architecture’ experiments up, but the diners were oblivious - and the data from their university swipe cards was collected anonymously.
Emma Garnett, a conservationist from Cambridge’s Department of Zoology, who was lead author of the study, published in Nature Food, said: “Reducing meat and dairy consumption is one of the simplest and most impactful choices we can make to protect the climate, environment and other species.
“We’ve got to make better choices easier for people. We hope to see these findings used by catering managers and indeed anyone interested in cafeteria and menu design that promotes more climate-friendly diets.”
The experiment was run at colleges with 600 students and 900 students over two years. The cafeteria customers were presented with vegetarian and meat options in differing orders for weekday lunch and dinner. The pattern was changed each month.
It was only when vegetarian meals were presented first, and at the extra distance, that the study found a rise in plant-based choices.
To confirm their findings, the researchers cut the gap in the cafeteria where this was recorded to just 67cm - and vegetarian sales plummeted.
In fact, with such a small gap, vegetarian dishes fared even worse when put first in line, falling almost 30 per cent compared to days when meat was presented first.
“We think the effect of the metre may be down to the additional effort required to seek out meat. If the first bite is with the eye, then many people seem perfectly happy with an appetising veggie option when meat is harder to spot,” said Emma.
“All cafeterias and restaurants have a design that ‘nudges’ people towards something. So it is sensible to use designs that make the healthiest and most sustainable food options the easiest to pick without thinking about it.
“We know that information alone is generally not enough to get us to change damaging habits. More research is needed on how to set up our society so that the self-interested default decision is the best one for the climate.”
Some 58 per cent of greenhouse gases created globally by food come from livestock and aquacultures behind meat, fish, dairy and eggs. They also take up 83 per cent of farmland - yet contribute just 18 per cent to the world’s calorie intake.
Previous work by Emma and her colleagues, published last autumn, showed that adding an extra vegetarian option in cafeterias cuts meat consumption without denting overall sales.
Her research has helped influence food policy at the university, where the catering service has cut the amount of meat on its menus.
University cafeterias - outside of those at colleges - achieved a 33 per cent reduction in carbon emissions per kilogram of food purchased, and a 28 per cent reduction in land use per kilogram of food purchased.
The UK’s public sector caterers have pledged to cut the amount of meat used in schools and hospitals by 20 per cent.
Cambridge researchers also recently recommended eating less meat to reduce the risk of future pandemics.
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