Health outcomes, environmental impacts, and diet costs of adherence to the EAT-Lancet Diet in China in 1997–2015: a health and nutrition survey

BACKGROUND: In 2019, the EAT-Lancet Commission proposed a global reference dietary pattern. Although research on the EAT-Lancet reference diet and its associations with mortality, cardiovascular disease, type 2 diabetes, dietary environmental impacts, and cost of diets is increasing, studies done in low-income and middle-income countries remain scarce. This study aimed to assess the health outcomes, environmental impacts, and dietary costs of adherence to the EAT-Lancet reference diet in China. METHODS: In this health and nutrition survey study, 16 029 participants from the China Health and Nutrition Survey cohort (1997-2015) were included at baseline. All-cause mortality was reported by family members and risk of cardiovascular disease and type 2 diabetes was self-reported. 3-day 24 h recall was used to assess adherence to the EAT-Lancet reference diet (Eat-Lancet Diet Index [ELDI]), diet-related environmental impacts (greenhouse-gas emissions [GHGE]), total water use (TWU), land use, and dietary costs in each survey round. Hazard ratios (HRs) for the ELDI-score were obtained by Cox models with time-varying covariates, adjusted for potential confounders. Multilevel mixed-effects linear regression was used to assess the association of environmental impacts and dietary costs to the ELDI score. FINDINGS: During a median follow-up of 9·86 years, 803 new cases of incident type 2 diabetes, 563 new cases of cardiovascular disease, and 908 cases of all-cause mortality were recorded. At baseline, the ELDI score ranged from 9·4 points to 110·8 points on a scale of 0 to 140, with a mean of 55·3 points (SD 11·8). With each SD increase in the ELDI score, there was an 8% decreased risk of mortality (95% CI 2·2-14·1), a 16·1% decreased risk of cardiovascular disease (9·2-20·3), and a 25·3% decreased risk of type 2 diabetes (19·5- 28·4). Each SD increase in the index was associated with a decrease of 2·2% (95% CI -2·6 to -1·8) in GHGE, 2·3% (-2·6 to -2·0) in land use, no association with TWU, but an increase in diet costs of 3·3% (2·8 to 3·8). INTERPRETATION: High adherence to the ELDI was associated with a lower risk of mortality, cardiovascular disease, and type 2 diabetes. However, the association with diet-related GHGE and land use was modest, and adherence was also linked to higher diet costs. The study advocates for the integration of sustainable indicators into future Chinese dietary guidelines. Additionally, policy measures such as agricultural subsidies on fruit and vegetable and carbon taxes on red meat are recommended to increase affordability, reduce environmental impact, and enhance the overall sustainability of dietary practices in China. FUNDING: The China Scholarship Council and the National Natural Science Foundation of China.