Modelling the drivers of a widespread shift to sustainable diets

by Sibel Eker (presenting author)1, Gerhard Reese2, Michael Obersteiner1

1: IIASA, Austria; 2: University of Koblenz-Landau


Lifestyle change is considered an important demand-side measure to mitigate climate change, to reduce environmental degradation and to achieve sustainable development goals. Food system is a resource-intensive sector where such lifestyle changes can lead to significant sustainability benefits. In particular, a reduction in global meat consumption can significantly reduce the adverse environmental effects of the food system, yet it requires widespread diet changes. Such shifts to sustainable diets depend on several behavioural factors, which are not yet addressed in relation to the food system.

This study links a behavioural diet shift model to an integrated assessment model to identify the main drivers of global diet change and its implications for the food system. Results show that the social norm effect, for instance the extent of vegetarianism in the population that accelerates further switch to a vegetarian diet, and self-efficacy are the main drivers of widespread diet changes. These findings stress the importance of value-driven actions motivated either by intrinsic identity or by group dynamics over health and climate risk perception in steering the diet change dynamics.

This study can be used to prioritize the issues and factors to guide future research on lifestyle changes. It can subsequently assist the formulation of potential policy interventions. The modelling framework used in this study is generalizable and transferrable to other lifestyle change domains.