More habitual deviation alleviates the trade-offs between dietary health, environmental impacts, and economic cost

Dietary transition provides a promising demand-side strategy for sustainable development, although challenges lie in balancing the trade-offs between human health, environmental sustainability and economic affordability. Our study revisits the trade-offs through the perspective of population heterogeneity. Specifically, transitioning the Chinese diet from its 2011 baseline to a healthier alternative with minimal behavioral adjustments could intensify environmental and economic impacts by 1.3–2.3 times. Conversely, relaxing behavioral constraints can yield both environmental and economic benefits. Specifically, replacing red meats (beef, mutton, pork) with poultry and seafood helps reduce cost, while substituting both red meats and seafood with more poultry, fruits, and vegetables enhances environmental benefits. However, this adaptive approach is not universally applicable. Stringent constraints aimed at mitigating environmental or economic impacts may inadvertently marginalize specific groups, such as the rural, elderly, or low-income populations, denying them the advantages of healthier dietary options. These findings highlight the necessity of developing inclusive strategies that support the healthy dietary shift of vulnerable groups.