Nudging healthy and sustainable food choices: three randomized controlled field experiments using a vegetarian lunch-default as a normative signal.

BACKGROUND: This study investigates a simple, generic and easily scalable nudge to promote healthy and sustainable food choices at conferences by using a vegetarian lunch-default as a normative signal. METHODS: At three conferences, participants registering electronically were randomized into two groups: Group 1 received a standard lunch registration presenting a non-vegetarian buffet as the default, but allowing the active choice of a vegetarian option; Group 2 received a registration presenting a vegetarian buffet as the default, allowing the active choice of a non-vegetarian option. The study also assessed gender differences for two of the conferences and the participants' acceptance of the nudge at one of the conferences. RESULTS: In experiment A the vegetarian choice increased from 2% to 87% (N = 108, P < 0.001). In experiment B it increased from 6% to 86% (N = 112, P < 0.001). In experiment C it increased from 12.5% to 89% (N = 110, P < 0.001). A significant tendency for men, but not women, to opt out of the vegetarian default was found and a clear majority of participants reported positive attitudes toward the nudge. CONCLUSIONS: Changing the lunch-default to a vegetarian option is an effective, generic, easy to scale and well-accepted nudge to promote healthy and sustainable food choices at conferences.

Meeting statement: Call to action for step-change in health behaviours.

Background: Enabling, supporting and promoting positive health-related behaviours is critical in addressing the major public health challenges of our time, and the multifaceted nature of behaviours requires an evidence-based approach. This statement seeks to suggest how a much-needed enhanced use of behavioural and cultural science and insights for health could be advanced. Study design and methods: and methods: Public health authorities of Europe and Central Asia and international partner organizations in September 2023 met in Copenhagen, Denmark, to discuss the way forward. Drawing on 1) country reporting to WHO, 2) interview study with public health authorities and 3) the meeting deliberations, this meeting statement was developed. Results: The meeting statement presents a joint call for step-change accelerated use of evidence-based approaches for health behaviours. Actionable next steps for public health authorities and international and regional development partners in health are presented. Conclusions: The way forward involves increased resource allocation, integration of behavioural insights into health strategies, advocacy through case and cost-effectiveness examples and capacity building.