Especially, olive oil improved glycemic control in reducing fasting blood glucose (MD: −0.44, 95% CI: −0.66, −0.22), HbA1c (MD = −0.27, 95% CI: −0.37, −0.17), insulin (SMD = −0.28, 95% CI: −0.51, −0.05), and homeostatic model assessment for insulin resistance (HOMA‐IR) (SMD = −0.19, 95% CI: −0.35, −0.03). The gene discussed is INS; the disease is Insulin resistance.