Construction and Empirical Test of a Three-Dimensional Collaborative Optimization Model for Sustainable Transformation of National Food Systems

The global food system's overemphasis on efficiency and profitability has triggered environmental degradation, food insecurity, and nutritional imbalance. This study constructs an integrated Environment-Equity-Economy (EEE) Model consisting of three interlocking sub-models. It adopts a Logistic Model to simulate the gradual transition to plant-based diets driven by an animal product tax, establishes a government-led food surplus redistribution mechanism funded by a Food Equity Tax, and quantifies the economic trade-offs of these policies. The application of the model to China and Finland illustrates its potential effectiveness. Under the proposed policy framework, simulation results for China indicate a potential 25.79% reduction in food system greenhouse gas emissions by 2050 and elimination of food insecurity by 2029, with an estimated 5.14% net profit decline. For Finland, the projections suggest a 33.22% emission reduction by 2040 and hunger elimination by mid-2027, with a 9.77% net profit loss. Subject to robustness verification through sensitivity analysis, the model appears applicable across countries at different development levels, offering a quantifiable framework for advancing sustainable and equitable food system transformation aligned with UN SDG 2 and SDG 13.