The main objective of PLAN’EAT (Food systems transformation towards healthy and sustainable dietary behaviour) will be to foster the transition to HSDB through an in-depth understanding of its underlying factors and drivers and through the design of effective recommendations, tools and interventions targeting food system actors. Across the world, dietary patterns are shifting towards dominant food consumption patterns and eco-agri-food systems that have high health, societal and environmental costs1. Without a significant change in current trends, non-communicable diseases (NCDs) will continue to rise while the quality and quantity of available natural resources will decline2. As dietary behaviour is a strong determinant of food consumption, it represents a key lever for action to transform food systems and vice versa. PLAN’EAT will aim at implementing an evidence-based, multi-actor, multi-layered and systemic approach at macro (food system), meso (food environment) and micro (individual) levels. Various socio-cultural and geographic contexts will be considered by implementing 9 Living Labs (LLs) in different European areas, 4 pan-European food value chain Consultation and Working Groups (CWGs) and 1 Policy Lab. In the LL, the dietary patterns of specific population groups will be mapped and ‘monetised’ in terms of environmental, socio-economic and health impacts through True Cost Accounting (TCA). The factors influencing dietary behaviours with the highest potential for change (i.e., high impact behaviours) will be analysed. The knowledge and scientific evidence obtained will feed into the co-design of more than 10 effective solutions adjusted to different contexts and end-users, corresponding to PLAN’EAT Project Results (PR).