Social Interactions for Sustainable Food Choices: Meeting the Target for Meat Intake in the United Kingdom.

Background: Substantial shifts in contemporary diets are needed to halt the growing burden of chronic diseases and the accelerating climate crisis. Achieving this will require strong action and the use of policy instruments that can aid consumers in making the right dietary choices. Real-life evidence on changing dietary behaviors within complex food systems at scale demands resources and research that might not be realistic to acquire or realize. Objectives: This project applied innovative models to predict the dietary and environmental effects of broad-scale strategies designed to transform dietary behaviors among consumers. Scenarios were numerically simulated using agent-based opinion-dynamics models to evaluate the impact of governmental influence on people's consumption of meat, vegetables, pulses, and meat alternatives. Methods: We considered the problem of influencing the opinions of a group of agents (representing the UK population) connected in a social network over a sequence of campaigns to achieve convergence to 2 different targets: achieving the UK Climate Change Committee's goal of 35% and 50% average reduction in meat consumption by 2030 and 2050, respectively. The opinion dynamics comprised consumers (i.e., agents), with empirically derived baseline food intake patterns (i.e., initial opinions) and sociodemographic attributes. Changes in environmental impacts following changes in consumption were quantified. Results: In a scenario of high governmental influence, uniform in the population, achievement of the 35% and 50% meat reduction goals corresponded to ∼5.2 and ∼8.1 y, respectively. As meat consumption reduced, intake of vegetables, pulses, and meat alternatives increased by 84.7%, 108.5%, and 30.8%, respectively (-35% scenario). Greenhouse gas emissions, land use, water use, and scarcity-weighted water were reduced by -23.8%, -20.2%, -0.5%, and -14.5%, respectively (-35% scenario). Conclusions: The findings of this project provide valuable insights for policymakers and governmental authorities to develop effective influence strategies aimed at promoting healthy and sustainable dietary habits.