Does food availability mediate the association between sustainable agricultural productivity and healthy diet affordability? Cross-country evidence

Healthy diet affordability is a critical component of food security and nutritional well-being, shaped by agricultural, climatic, and economic factors. This study examines the association between sustainable agricultural productivity (SAP), food availability (FA), agricultural climate pressure (ACP), inflation (INF), GDP per capita, and urbanization with healthy diet affordability (HDA) across 132 countries in 2021. Using the findings of ordinary least squares regression with HC3 robust standard errors model indicates that SAP (β = 0.252, p < 0.05) and GDP per capita (β = 0.059, p < 0.05) are positively associated with HDA, whereas ACP (β = −0.092, p < 0.05) and INF (β = −0.344, p < 0.05) are negatively associated with it. Mediation analysis further reveals that SAP is positively associated with FA (β = 0.335, p < 0.001), which is, in turn, positively associated with HDA (β = 0.530, p < 0.001). The estimated indirect association is 0.178, while the direct association remains significant (β = 0.293, p < 0.01), indicating complementary mediation through food availability. The findings highlight the importance of SAP, FA, macroeconomic conditions, and climate-related pressures in understanding cross-country differences in HDA. However, the cross-sectional design limits causal interpretation.