China’s diet urgently needs to establish a sustainable evaluation system to address critical challenges

Assessing the diet’s sustainability is critical to advancing the Sustainable Development Goals. Dietary patterns have shifted from plant-based to animal-based, elevating health risks, intensifying environmental burdens, and necessitating systematic assessment and scientific responses. Current research on dietary sustainability is largely confined to national-level analyses, with few regional or provincial spatiotemporal studies. The study developed a tripartite framework integrating health, economic, and environmental indicators and applied it to 37 years of longitudinal data (1987–2023) to assess dietary sustainability at national, nine agricultural regions, and provincial scales. Nationally, the comprehensive sustainability of diets initially rose, then declined. While health and economic indicators improved, persistent environmental degradation emerged as the primary constraint. Across all nine agricultural regions, comprehensive sustainability increased, driven by gains in health and economic dimensions, despite universal declines in environmental sustainability. Provincial analysis revealed a shift in comprehensive sustainability from predominantly moderate—with some strong areas—to primarily strong, with scattered moderate areas. Notably, Tibet was the only province to register a decline. Health sustainability transitioned from a predominantly moderate pattern, marked by localized strengths and weaknesses, to an East‑West gradient, with higher levels in the East. Economic sustainability improved across all provinces, rising from weak‑to‑moderate levels to a very strong status. For environmental sustainability, all provinces except Gansu, Guizhou, Ningxia, and Shanxi showed a declining trend, with eastern regions of China experiencing pronounced deterioration. This spatial pattern shifted from a predominantly moderate baseline—encompassing both strong and weak areas—to one in which eastern sustainability falls below that in the west. Results revealed a structural contradiction from the imbalanced environmental, health, and economic dimensions’ synergies. Moving forward, coordinating the balanced development of environmental and other dimensions and reshaping the multidimensional balanced development path of the dietary system is essential.