Patients on the diet with added fiber had improvements in body mass index (BMI) (standardized mean difference (SMD) = −0.494, 95% confidence interval (CI): −0.864 to −0.125, p = 0.009); alanine aminotransferase (ALT) (SMD = −0.667, 95% CI: −1.046 to −0.288, p = 0.001); aspartate aminotransferase (AST) (SMD = −0.466, 95% CI: −0.840 to −0.091, p = 0.015); fasting insulin (SMD = −0.705, 95% CI: −1.115 to −0.295, p = 0.001); and homeostasis model assessment for insulin resistance (HOMA-IR) (SMD = −0.619, 95% CI: −1.026 to −0.211, p = 0.003). The gene discussed is GPT; the disease is Insulin resistance.