Source record
Impact of increasing vegetarian availability on meal selection and sales in cafeterias
Emma S. Garnett, Andrew Balmford, Chris Sandbrook, Mark A. Pilling, Theresa M. Marteau (2019). Proceedings of the National Academy of Sciences. University of Cambridge.
Key findings
- Doubling the share of vegetarian options from a quarter to a half raised vegetarian meal sales by roughly 15 percentage points in the observational data.
- In the experimental arm the same doubling raised sales by about 7.8 percentage points.
- Total sales did not fall, so the shift did not come at the cost of custom.
Record
- Source type
- Peer Reviewed Study
- Study type
- Randomised Controlled Trial
- Topics
- Menus & catering, Climate & emissions
- Geography
- United Kingdom
- Population
- University college cafeterias
- Sample size
- 94,644 meals
- Funding & conflicts
- Academic funding; no industry involvement reported.
- Source quality
- Strong evidenceLarge sample, a real setting and both observational and experimental arms reported side by side.
Limitations
- University cafeterias with a captive audience are not a supermarket, a high street or a workplace canteen.
- The observational and experimental estimates differ by roughly a factor of two, which is a caution about the size rather than the direction.
Statistics we use from this source
- 15percentage pointsRise in vegetarian meal sales when vegetarian options doubled, observational
- 7.8percentage pointsRise in vegetarian meal sales when vegetarian options doubled, experimental
Claims this source supports
EnvironmentModerate evidence
Increasing the share of plant-based options on a menu increases the share of plant-based meals sold, without reducing total sales.
Yes, in canteen settings. Doubling vegetarian availability raised vegetarian sales by roughly 8 to 15 percentage points, and almost nobody noticed the change.