Researchers found that prompting consumers to think about their menu choices before they were ‘nudged’ increased the effectiveness of the nudge by 30 per cent.

In an experimental setting, the researchers found this new tool of behaviour change – known as nudge+ - resulted in consumers making menu choices with a carbon footprint three-quarters less than those in a baseline group who had experienced no nudging.

The researchers said: “These experimental findings generate policy insights relevant for a growing food–delivery sector, mainly as diets continue to contribute substantially to greenhouse gas emissions, globally as well as in the United Kingdom.”

“Our findings suggest that food delivery companies can contribute to net–zero goals by introducing small design changes to their user–engagement platforms.”

“For example, our best case of a nudge+, where reflection precedes the nudge is readily implementable through push–in notifications that engage with citizen’s pro–environmental preferences before they check out to order their meal.”

The online study involved more than 3,000 participants in the UK who were presented with a restaurant menu before being assigned at random to a treatment condition. Participants were then re-directed to a check-out screen and asked to place their order for meal delivery, with the carbon footprint of their menu choices recorded.

The findings were revealed in a new paper co-authored by Sanchayan Banerjee (LSE/King’s), Dr Matteo Galizzi (LSE), Professor Peter John (King’s College London) and Professor Susana Mourato (LSE).

The researchers also found that being open and transparent about the nudge did not lead to any backfire effects and showed that the benefits of nudge+ were only realised when people were made to think before the nudge, and not after it.

The findings of the study are particularly relevant amid the rapid growth of the food-delivery sector, which is currently valued at more than $150billion and saw rapid expansion during the COVID-19 pandemic.