Effects of ketogenic diet on obesity indices, lipid profile, and glycemic control parameters in athletes: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials
Systematic review and meta-analysis reveals increased cholesterol levels alongside elevated HDL-c in athletes, highlighting complex cardiovascular trade-offs of the ketogenic diet.
Key Points
To quantify the pooled effects of the ketogenic diet on lipid profiles, obesity indices, and plasma glucose concentrations in athletes.
Systematic search of PubMed, Scopus, Web of Science, and Google Scholar conducted up to January 2026.
Identified and analyzed 14 randomized controlled trials using random-effects meta-analytic modeling and GRADE certainty assessment.
Ketogenic diet significantly increased HDL-c (WMD: 9.18 mg/dL, 95% CI: 6.47 to 11.90; P < 0.001), but also substantially elevated total cholesterol (WMD: 42.88 mg/dL, 95% CI: 29.40 to 56.35; P < 0.001) and LDL-c (WMD: 44.41 mg/dL, 95% CI: 28.82 to 59.99; P < 0.001), supported by high-quality GRADE evidence.
No statistically significant changes were observed for triglycerides (WMD: -1.96 mg/dL, 95% CI: -17.20 to 13.27; P = 0.801), fasting plasma glucose (WMD: -2.30 mg/dL, 95% CI: -6.11 to 1.51; P = 0.236), or body weight (WMD: -0.04 kg, 95% CI: -2.25 to 2.17; P = 0.971).
No statistically significant pooled effects occurred for fat mass percentage (WMD: -0.54%, 95% CI: -1.31 to 0.24; P = 0.174) or fat-free mass percentage (WMD: -0.57%, 95% CI: -1.72 to 0.59; P = 0.336).