Abstract
The sustainable and stable population support capacity of a country or region is of great concern. This study proposes a new method for evaluating the land carrying capacity (LCC) based on food nutrition demand and establishes a clear link between nutritional health and land. We delved into the evolving dynamics of food consumption and production structures in China between 1990 and 2020, with a focus on the spatial variations among its 31 provinces. The objectives of this study were to assess the status of LCC, identify the critical nutritional factors constraining LCC enhancement, and propose differentiated pathways for improving LCC. The results showed that: (1) There has been a steady increase in the annual consumption of animal-based products, while plant-based product consumption has declined. (2) Overall, food supply capacity has expanded, displaying an "east high, west low" trend, resulting in an imbalanced food supply level. (3) The LCC for energy and carbohydrates exhibited continuous fluctuating growth but displayed a declining trend after 2018. (4) The pressure on land carrying capacity has shifted from a state of "surplus" to "abundant surplus," signifying a safe food system level. However, significant spatial variations persist, leading to shortages and surpluses. Therefore, this work suggests that addressing these disparities requires the optimization of food consumption structures and increasing the supply of animal-based foods. This approach leverages regional advantages and reduces disparities in regional LCCs. This study provides a valuable reference for ensuring food security in response to unprecedented global changes in sustainable development.