Introduction
Across Europe, animal-based proteins remain dominant but environmentally unsustainable dietary choice. Replacing them with alternative protein foods—including plant-based, insect-based, or microbial sources—could substantially reduce environmental impacts. Consumers' dietary behaviors, shaped by individual, social, and environmental factors, can influence other stakeholders in food system and drive systemic transformations toward sustainability.


Purpose
This study applied system mapping approach to explore the determinants perceived by the food system stakeholders as key determinants of an inclusion of alternative proteins in daily diets of European consumers. The aim was to identify key leverage points—determinants most interconnected with others within the system, and respective cross-European similarities and differences.


Methods
Seventeen participatory system mapping workshops were conducted across 13 European countries, involving N = 166 food system stakeholders (e.g., food producers, policymakers, nutritionists, and consumers). Using group model building methods, participants collaboratively developed 17 system maps illustrating determinants of inclusion of alternative proteins into a daily diet. Centrality indices were computed to identify key leverage points, and feedback loops were analyzed to explore system dynamics and cross-country patterns.


Results
Common leverage points identified across six to eight national maps included consumer education and knowledge about alternative protein food, social norms and encouragement, and the influence of advertising and social media. Additional leverage points, present in at least three system maps, involved health perceptions, curiosity or neophobia, national food culture, and views on ultra-processing, sustainability, and animal welfare. Stakeholders emphasized consumers' beliefs and behaviors as central to shaping food system change.


Conclusions
This study provides new insights into complex, interconnected determinants shaping European food systems and the inclusion of alternative protein foods into daily diets of European consumers. Identifying leverage points and feedback loops offers guidance for policymakers and other stakeholders aiming to design interventions that accelerate transition toward more sustainable, protein-diverse diets.