INS and acne: In studies on the mechanism of dietary factors that affect acne, it was also shown that hyperinsulinemia caused by high glycemic index (GI) diets triggers acne by increasing the ratio of IGF-1 to insulin-like growth factor binding protein-3 through the insulin/IGF-1 signaling pathway, thereby enhancing the effect of IGF-1 [10]; conversely, low GI diets significantly reduced acne severity and improved insulin sensitivity [25].