International food trade increased the food security gap between high and low economic development groups

International trade serves as a crucial pathway for enhancing global food security and equality amid severe food crises worldwide. Under globalization, economic development has profoundly influenced food trade, while disparities in food purchasing power among different economic development groups have led to uneven food security outcomes. However, the varying contributions of international trade to food security across these groups remain to be quantitatively elucidated. This study categorized countries into four economic development groups—high, high-medium, medium-low, and low—and examined changes in their food security scores from 2010 to 2019. The cross-group contributions of international trade to food security across these groups were compared. The results revealed that the food security score of the high economic development group was 9.22 times higher than that of the low economic development group. From 2010 to 2019, the high economic development group exhibited a significant upward trend in food security scores, whereas the low economic development group showed a significant decline. Moreover, international trade contributed significantly to both cross-group and within-group food security in the high economic development group, while its contribution to the low economic development group remained negligible. These findings demonstrated that international trade has further widened the food security gap between the high and low economic development groups, and its limited contribution to the low economic development group has failed to reverse the declining trend in their food security scores. This study quantified the divergent impacts of international trade on food security across economic development groups, providing valuable insights for optimizing global food trade policies—particularly in addressing the food security challenges faced by low econominc development group.