Greater choice of vegetarian options ‘can nudge diners away from meat’

A greater choice of vegetarian and vegan meals on a menu can nudge diners towards choosing them instead of meat or fish, a study has suggested.

Researchers at Cambridge University analysed 94,000 meal choices made at three colleges where diners make their purchases on university cards topped up with credit.

They found that doubling the number of vegetarian options on the menu from one in four to two in four reduced the proportion of meat-rich purchases by between 40% and 80%, without affecting overall food sales.

Data, including the names of the colleges involved, was anonymised as part of the study.

The research team found that the biggest increases in plant-based dining were among the most carnivorous quartile of customers: people who had consistently picked meat or fish before a second vegetarian option was added.

The study indicated that there was not a “rebound effect” – that opting for a vegetarian lunch did not make a meat-heavy dinner more likely.

The findings are published in the journal Proceedings Of The National Academy of Sciences.

Lead author Emma Garnett, a conservationist from Cambridge’s Department of Zoology, said: “Shifting to a more plant-based diet is one of the most effective ways of reducing the environmental footprint of food.

“Replacing some meat or fish with more vegetarian options might seem obvious, but as far as we know no-one had tested it before.

“Solutions that seem obvious don’t always work, but it would appear that this one does.

“We’re not saying all cafeterias and restaurants should turn vegan overnight.

“But if food were the film industry, vegetarian and vegan meals need to land more starring roles, and meat dishes have got to stop hogging the limelight.”

The study had an observational and experimental component.

Two colleges provided data on days with different menu set-ups and a third college helped the researchers to conduct a “choice architecture” experiment during the autumn term of 2017.

At the third college, lunchtime menus alternated fortnightly between one vegetarian or vegan option as a control and then two for the experiment.

Co-author Theresa Marteau, professor of behaviour and health at Cambridge University, said: “Education is important but generally ineffective at changing diets.

“Meat taxes are unpopular.

“Altering the range of available options is more acceptable, and offers a powerful way to influence the health and sustainability of our diets.”

The catering service at Cambridge University has already removed beef and lamb from the menu for environmental reasons and has increased the number of vegetarian options available.

University cafeterias said earlier this month that as a result of the changes there had been a 33% reduction in carbon emissions per kilogram of food purchased and a 28% reduction in land use per kilogram of food purchased.