Legume-based pathways reveal opportunities and limits of protein self-sufficiency in the EU and UK

The European Union and United Kingdom (EU+) remain heavily dependent on imported high-protein feed, primarily soybeans, raising concerns about supply resilience and environmental impacts. We assess three legume-based pathways—trade, policy support, and dietary shift—against a 2030 projection horizon, using integrated regional agro-economic, farm-level, and life cycle assessment models. The trade pathway, simulating a complete interruption of protein imports, provides an analytical upper bound for domestic EU+ legume production. It drives substantial land reallocation (+1.5 million ha legume area) but fails to fully replace imports, resulting in higher prices (+150% for soybeans) and reduced livestock output (-3%), exposing systemic vulnerabilities. Farm-level results underscore economic incentives over agroecological potential. Policy support moderately increases legume cultivation with limited market impacts but improves farm-level viability where conditions are favourable. Dietary shifts increase pulse imports (+100%) but reduce global GHG emissions more effectively than supply-side measures. Overall, the results highlight legumes’ potential, limits of self-sufficiency, and the complementary roles of economic incentives and demand-side measures for sustainable and resilient EU+ food systems.