This study investigates the role of defective hepatic autophagy in obesity and its impact on insulin resistance and ER stress. In both genetic and dietary models of obesity, severe downregulation of autophagy, particularly Atg7 expression, was observed in the liver. Suppression of Atg7 led to defective insulin signaling and elevated ER stress, while restoring Atg7 expression in obese mice improved insulin action and reduced ER stress. The beneficial effects of Atg7 restoration were prevented by blocking Atg5, suggesting that autophagy is crucial for regulating insulin action. The findings highlight the importance of autophagy in maintaining metabolic homeostasis and provide insights into the pathogenesis of insulin resistance and type 2 diabetes.This study investigates the role of defective hepatic autophagy in obesity and its impact on insulin resistance and ER stress. In both genetic and dietary models of obesity, severe downregulation of autophagy, particularly Atg7 expression, was observed in the liver. Suppression of Atg7 led to defective insulin signaling and elevated ER stress, while restoring Atg7 expression in obese mice improved insulin action and reduced ER stress. The beneficial effects of Atg7 restoration were prevented by blocking Atg5, suggesting that autophagy is crucial for regulating insulin action. The findings highlight the importance of autophagy in maintaining metabolic homeostasis and provide insights into the pathogenesis of insulin resistance and type 2 diabetes.