Province-specific sustainable diets in China considering nutrition, environment, affordability, and acceptability

Sustainable dietary transition is widely identified essential in addressing the nutrition, environment, and health trilemma. This is particularly important for China, the world's most populous country which is undergoing a rapid dietary structure change. Here, we used a nonlinear optimization algorithm to identify a nutritionally adequate, environmentally friendly, economically affordable, and culturally acceptable diet for each of the 31 provinces in mainland China. We found that province-specific dietary shifts could reduce the carbon, water, land, nitrogen, and phosphorus footprints of China's food consumption by 9.5-25.3%, 10.7-19.1%, 22.4-32.9%, 30.8-40.2%, and 21.4-34.5%, respectively, while meeting the daily recommended intake of essential nutrients and not exceeding current food expenditures. The variation in required food intake was highly province-specific; however, in general, there was a need to reduce the intake of meat, grains, and edible oils and increase the intake of vegetables, fruits, legumes, tubers, and dairy products. Our findings highlight the importance of provincespecific diet optimization, which can greatly improve acceptance and feasibility of sustainable dietary transition, guide individuals to change their food consumption behavior, and inform policymakers towards regionally tailored food policies.