INS and Insulin resistance: Twenty-one randomized controlled trials (RCTs) were included, and the low-ratio LA/ALA diet had no significant effect on fasting blood sugar (FBS, WMD: 0.00 mmol/L, 95% CI: −0.06, 0.06, p = 0.989, I2 = 0.0%), insulin levels (WMD: 0.20 μIU/mL, 95% CI: −0.23, 0.63, p = 0.360, I2 = 3.2%), homeostatic model assessment insulin resistance (HOMA-IR, WMD: 0.09, 95% CI: −0.06, 0.23, p = 0.243, I2 = 0.0%), and hemoglobin A1c (HbA1c, WMD: −0.01%, 95% CI: −0.07, 0.06, p = 0.836, I2 = 0.0%).