Shift from feeding to sustainably nourishing urban China: A crossing-disciplinary methodology for global environment-food-health nexus.

Dietary change is a win-win opportunity to address the nexus of health and the environment. To prevent city dwellers from developing non-communicable diseases, in 2013, China updated the 2000 version of nutrition-based dietary reference intake (DRI) guidelines. However, whether the DRI guidelines have a positive effect on the environment is not well understood. Here, we explored the systematic effects of urbanization on China's health and environmental nexus based on survey data. Then, we optimized the diets of 18 age-gender groups to reduce carbon emissions, water consumption, and land use while meeting the healthy nutrition goals of both DRI guidelines. The results showed that the optimal diets based on the DRI 2013 outperformed these on DRI 2000 in improving China's environmental sustainability, although these diets did not always perform better at an individual scale. Our findings suggest that dietary changes can reduce carbon, water, and ecological footprints by 24%, 15%, and 22% in 2050, respectively; however, the differences in age-specific and gender-specific health goals cannot be neglected.