Shruti Jain

National dietary guidelines and scientific consensus both call for a broader adoption of plant-rich diets to improve both health and environmental outcomes. Such transitions would redistribute production across different kinds of farmers, with consequences for farming livelihoods and agricultural support. Yet the role of different farmer types in dietary transitions remains poorly understood. Here we combine data on the global distribution of crop production across farm-size classes with scenario projections of production, consumption, and bilateral trade under five dietary pathways from 2020 to 2050, ranging from business-as-usual to plant-based, allocating modelled flows to small (< 5 ha), medium (5–50 ha), and large (> 50 ha) farms. We find that small-scale farms continue to produce the majority (> 50%) of the world’s crops across different dietary pathways, but the volumes and commodities they are expected to produce, and the trade corridors they follow, vary substantially across scenarios. Our results suggest that small-scale producers will play a critical role in the expansion of legumes, nuts, fruits, and vegetables under plant-rich diets across East Asia and the Pacific, South Asia, and Sub-Saharan Africa, while large-scale feed-crop producers in the Americas will see a contraction. Dietary transitions also reshape the composition of international trade, with the large-farm share of global trade volumes falling from 58% in 2020 to 41–48% under plant-rich diets by 2050. Accounting for the differentiated roles of farmers across different dietary futures, currently overlooked by aggregated analysis of food production needs, is crucial to identify how the costs, benefits and responsibilities are shared among farmers in a sustainable food transition.

Food and beverage (F&B) manufacturers can support or hinder the transition towards a more sustainable food system. Yet, there is limited evidence about their potential to improve the nutritiousness and reduce the environmental impact of the F&B sector. Here we develop an approach to estimate the nutritional quality and environmental impact of the product lines of 44 major F&B manufacturers in the UK. We find considerable variation in terms of nutritional quality and environmental impacts across manufacturers operating within the same food retail category and within existing F&B product portfolios. We identify how changing the types of product sold by these manufacturers offers potential for nutritional and environmental benefits. For some of the F&B manufacturers assessed, changes to 10% or less of their product line could deliver more than half of the potential gains in nutritional quality or sustainability.

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 12 228 urban centers across 159 countries. We show that diet-related greenhouse gas emissions (GHGE) are highly concentrated in a small number of cities: The 200 urban centers with the largest footprints account for 39.8% of global urban population and 45.6% of total global urban dietary emissions. Overall, adoption of the EAT-Lancet 2.0 diet across all studied centers delivers a modest net reduction in total footprints (≈5%–16%). However, this aggregate outcome masks substantial variability: high-income centers achieve considerable reductions through lower meat and dairy consumption, while lower-income centers presently consuming below EAT-Lancet recommended levels experience footprint increases, partially offsetting global gains. Within transnational city networks (C40 Cities, Eurocities, and Milan Urban Food Policy Pact members), where member centers are predominantly high-income, EAT-Lancet 2.0 adoption delivers substantially larger reductions of 22%–50% in GHGE, underscoring the policy relevance of targeted urban-level dietary interventions. Complementary supply-side interventions, including decarbonization of agricultural production, processing, and distribution, offer additional reductions, indicating that dietary and supply-side levers must be deployed jointly. Our results highlight the need for context-specific urban dietary strategies. The resulting database, MATILDA-City, provides a globally harmonized evidence base to benchmark, rank, and monitor urban-level dietary footprints, supporting municipalities to coordinate actions toward sustainable food systems.

The potential for sustainable dietary transitions to benefit human health and environmental sustainability is well understood. Yet their implications for the geography of global food production and trade remain poorly quantified. We model how five dietary pathways might reshape bilateral trade networks through 2050 under different climate and trade scenarios. Dietary transitions could increase trade volumes by 50-135%, while substantially altering trade composition: under plant-rich scenarios, fruits and vegetables rise from 9% to 28% of traded crops, while grains decline from 34% to 24%, driven by reduced feed trade. These shifts are projected to reconfigure trade geography, with Sub-Saharan Africa emerging as a major exporter of legumes and nuts, while grain and soybean exports from the Americas to Asia decrease. Relaxing trade constraints increases both import dependence and supplier concentration, while dietary pathways shape import dependence in commodity-specific ways. Our findings help anticipate trade implications of dietary policies and trends.

Understanding the environmental impacts of food products is essential for a sustainable food systems transformation, yet such information remains sparse and non-standardized. Here we analyse nearly 475,000 products across 74 countries, quantifying the impacts on land use, greenhouse gas emissions, biodiversity loss, eutrophication, and water stress. We find that the ranking of category-level environmental impacts is consistent across countries, with the highest impacts observed in categories such as animal products, coffee, nuts and seeds, and the lowest in fruits, vegetables, and beverages. However, the absolute impacts of products within categories vary across geographies due to differences in product composition and ingredient sourcing patterns. For some products, sourcing differences can substantially alter footprints, sometimes outweighing compositional differences, highlighting the potential for targeted supply chain interventions. Our study provides a robust, comparable methodology for estimating product-level environmental impacts that can support policies aimed at shifting demand toward lower-footprint foods.

Subnational data on both domestic and international cereal flows is essential for understanding food supply chain vulnerabilities, yet no such dataset exists at a global scale. This study estimates spatially resolved cereal flow networks across 3,540 subnational regions in 195 countries using a triply-constrained spatial interaction model that simultaneously enforces regional supply-demand balance and consistency with reported bilateral trade statistics. Domestic distribution accounts for approximately 25% of global cereal consumption, and 17% is met through international trade. Nearly half of net importing countries contain surplus regions that supply grain domestically, while virtually every net exporting country retains deficit regions reliant on inflows. Crop-disaggregated supply profiles reveal that subnational regions with similar aggregate trade dependency can have fundamentally different supply structures, differing in which crops dominate their consumption, whether those crops are sourced locally, domestically, or internationally, and how concentrated their sources are. Source concentration over exporting countries varies across subnational regions and across crops, revealing vulnerability hotspots that national-level assessments cannot detect. These subnational, crop-specific flow estimates can support targeted policy interventions to reduce supply chain vulnerabilities and enable more spatially precise environmental footprinting of food supply chains.

Subnational data on both domestic and international cereal flows is essential for understanding food supply chain vulnerabilities, yet no such dataset exists at a global scale. This study estimates spatially resolved cereal flow networks across 3,540 subnational regions in 195 countries using a triply-constrained spatial interaction model that simultaneously enforces regional supply-demand balance and consistency with reported bilateral trade statistics. Domestic distribution accounts for approximately 25% of global cereal consumption, and 17% is met through international trade. Nearly half of net importing countries contain surplus regions that supply grain domestically, while virtually every net exporting country retains deficit regions reliant on inflows. Crop-disaggregated supply profiles reveal that subnational regions with similar aggregate trade dependency can have fundamentally different supply structures, differing in which crops dominate their consumption, whether those crops are sourced locally, domestically, or internationally, and how concentrated their sources are. Source concentration over exporting countries varies across subnational regions and across crops, revealing vulnerability hotspots that national-level assessments cannot detect. These subnational, crop-specific flow estimates can support targeted policy interventions to reduce supply chain vulnerabilities and enable more spatially precise environmental footprinting of food supply chains.

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.