Offering vegetarian choices in schools may cut meat consumption

A study published in Proceedings of the National Academy of Sciences suggests that offering more vegetarian choices in school cafeterias may cut meat consumption without hurting overall sales.

Researchers from the University of Cambridge gathered over a year’s worth of mealtime sales data from three Cambridge college cafeterias. The new study had an observational and experimental component. For the observational studies, two colleges provided data on weekday term-time meal selections at both lunch and dinner during 2017. Meals were purchased using university cards topped up with credit, allowing researchers to analyze anonymized data that tracked what individual diners ate for each meal on every day.

This dataset contained 86,932 hot meals (excluding salads and sandwiches) and 2,140 repeat diners. The range varied between occasional days with no vegetarian or vegan dishes, to days where 75% of the options were veggie.

The researchers built statistical models to show that doubling the vegetarian offering, from a quarter to half of possible meals, increased the proportion of vegetarian sales by 62% in the first college, and 79% in the second college.

Caterers at a third college worked with researchers to conduct an experiment during the autumn term of 2017: lunchtime menus that alternated fortnightly between one veggie option (control) and two vegan options (experiment). Doubling availability increased the proportion of vegetarian sales by 41%, or almost 8 percentage points.

The team found the biggest increases in plant-based dining among the most carnivorous quartile of customers: those who had consistently picked meat or fish prior to the addition of a second veggie option. Moreover, the researchers detected no “rebound effect”—opting for a vegetarian lunch did not make a compensatory meat-heavy dinner any more likely.

Abstract