The dietary footprints and transition priorities of over 12,000 cities

Urban consumption plays a central role in driving global carbon emissions and is associated with a wide range of environmental pressures, including deforestation, water use, and biodiversity loss. As cities and networks of cities work to define and achieve quantitative sustainability goals, the lack of insight into their unique food footprints, shaped by each city’s specific dietary patterns and demographic composition, remains a significant obstacle. Here we combine demographic, group-specific diet, and supply-chain environmental footprint data to estimate the dietary footprints in 12,683 cities across 159 countries. We show that diet-related greenhouse gas emissions (GHGE) are highly concentrated in a small number of megacities. The 200 cities with the largest footprints account for approximately 15% of global population but nearly half of total global urban dietary emissions. Adoption of the EAT–Lancet 2.0 diet in the studied cities could modestly reduce total footprints (by 5–15%, depending on impact category). High-footprint cities have the greatest potential reductions from reducing meat and dairy consumption. However, these gains are largely matched by the potential rises in footprints from lower-income cities presently consuming below the EAT-Lancet recommended levels. Across transnational city networks (C40 Cities, Eurocities, and Milan Urban Food Policy Pact members) implementation of the EAT–Lancet 2.0 diet delivers substantial reductions 22–50% in GHGE, underscoring the policy relevance of city-level dietary footprinting. Our results highlight the need for context-specific urban dietary strategies. The resulting database, MATILDA-City, provides a globally harmonised evidence base to benchmark, rank, and monitor city-level dietary footprints, supporting municipalities to coordinate actions toward sustainable food systems.