Youth lead current dietary emissions while seniors increasingly drive total emission growth

Diets across age groups vary in both nutritional quality and greenhouse gas emissions, yet their relationship remains poorly understood in the context of population aging and evolving dietary patterns. We evaluated dietary emissions associated with 141 products across 22 age groups in 149 countries from 2000 to 2019, combining age-specific dietary intake from the Global Dietary Database with a consumption-based emission inventory derived from FAOSTAT. We quantified changes in emissions alongside shifts in nutritional quality and examined contributions of demographic and dietary factors. Adolescents and young adults generally had the highest per capita dietary emissions, while seniors contributed most to global emission growth, particularly in high- and upper-middle-income countries. Increased meat intake was a leading contributor to rising emissions and frequently coincided with declining nutritional quality. These findings highlight the need for dietary-emission mitigation efforts across age groups that account for demographic shifts, nutritional needs and national development contexts.