Affordability and nutritional challenges for the future of EAT diets: an economic modelling analysis

Affordability limits healthy diet adoption, especially in low-income settings, yet dietary shifts are key for transition to sustainable food systems. This study models how a diet in line with the 2025 EAT-Lancet Commission dietary transition might impact calorie availability, share of income spent on food, nutrition availability, and food prices.

We use the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) to estimate food price changes under three alternative Shared Socioeconomic Pathways and global adoption of a 2025 EAT-Lancet Commission diet by 2050. We analyse price shifts for the two cheapest commodities per food group, in each region, weighted on calorie availability per dollar. Additionally, we assess gaps between nutrient availability and reference nutrient intake and changes in the share of income spent on food for the whole diet.

Adoption of the 2025 EAT-Lancet Commission diet leads to heterogeneous impacts on the share of income spent on food and nutrient availability, with gains in folate, iron, and zinc, but declines in vitamin A by 2050. The combined price index for the cheapest two commodities declines by 2050 compared with 2020 in both higher-income and lower-income countries.

Although dietary shifts towards the 2025 EAT-Lancet Commission diet could offset some of the increases in prices seen in a business-as-usual world, we observed unintended effects on nutrient availability ratios, especially in lower-income countries. The decreasing price index for the cheapest two commodities reflects market adjustments to changes in demand and supply under scenario assumptions aligned with 2025 EAT-Lancet Commission goals for jointly improved human and environmental health. The observed nutrient deficiencies suggest the 2025 EAT-Lancet Commission diet limits on animal-sourced foods might be too strict for lower-income countries, which could exacerbate nutrient deficiencies in contexts where access to animal sourced foods is already low (eg, vitamin A), especially if there is no access to supplementation for meeting these nutritional requirements or other sources of dietary nutrients.

CGIAR Science Program on Policy Innovations (Area of Work 1-Foresight and Prioritization).