INS and polycystic ovary syndrome: Compared with isocaloric balanced diets (BDs), HPDs significantly reduced fasting insulin (−2.69 μIU/mL, 95% CI [−3.81, −1.57], P < 0.0001, I2 = 46%) and homoeostatic model assessment for insulin resistance (HOMA-IR−0.41, 95% CI [−0.80, −0.02], P = 0.04, I2 = 94%) in women with PCOS.