Table 2.
Summary of significant associations of ketogenic diet with health outcomes supported by moderate to high quality of evidence
| Source | Outcome | Population | Intervention | Duration of KD | Comparator | No. of studies (sample size) | Metric | Random effect size (95% CI) | P value | I2, % | GRADE rating | Clinical importance (MCID threshold) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sourbron et al. 2020 [16] | Seizure frequency reduction ≥ 50% from baseline | Children or adolescents (age 1–18 years) with refractory epilepsy | KD or MAD | 3–16 months | RD | 5 (n = 374) | RR | 5.11 (3.18 to 8.21) | < .001 | 0 | High | N/A |
| Rafiullah et al. 2022 [35] | Triglyceride, mg/dL | Adults with T2DM | KD | 3 months | RD | 4 (n = 283) | MD | -18.36 (-24.24 to -12.49) | < .001 | 0 | High | Yes (MCID 7.96 mg/dL) |
| Rafiullah et al. 2022 [35] | Triglyceride, mg/dL | Adults with T2DM | KD | 12 months | RD | 5 (n = 445) | MD | -24.10 (-33.93 to -14.27) | < .001 | 0 | High | Yes (MCID 7.96 mg/dL) |
| Rafiullah et al. 2022 [35] | LDL-C, mg/dL | Adults with T2DM | KD | 12 months | RD | 4 (n = 389) | MD | 6.35 (2.02 to 10.69) | .004 | 0 | High | Yes (MCID 3.87 mg/dL) |
| Rafiullah et al. 2022 [35] | HbA1c, % | Adults with T2DM | KD | 3 months | RD | 6 (n = 388) | MD | -0.61 (-0.82 to -0.40) | < .001 | 44.0 | Moderate | Yes (MCID 0.50%) |
| Castellana et al. 2020 [15] | Body weight, kg | T2DM adults with overweight or obesity | VLCKD | 4–6 weeks | LFD or RD | 2 (n = 142) | MD | -9.33 (-15.45 to -3.22) | < .001 | 0.1 | Moderate | Yes (MCID 4.40 kg) |
| Cao et al. 2021 [39] | Respiratory exchange rate | Athletes | K-LCHF | 4–6 weeks | HCD | 2 (n = 15) | SMD | -2.65 (-3.77 to -1.54) | < .001 | 0.8 | Moderate | N/A |
| Lee et al. 2021 [17] | Total cholesterol, mg/dL | Athletes | K-LCHF | 11–24 weeks | RD | 2 (n = 41) | MD | 1.32 (0.64,1.99) | < .001 | 0 | Moderate | No (10.05 mg/dL) |
Abbreviations: GRADE Grading of Recommendations, Assessment, Development, and Evaluations, HbA1c hemoglobin A1c, HCD high carbohydrate diet, K-LCHF ketogenic low-carbohydrate high-fat diet, KD ketogenic diet, LCD low-calorie diet, LDL-C low-density lipoprotein cholesterol, LFD low-fat diet, MAD modified Atkins diet, MD mean difference, MCID minimally clinically important difference, N/A not applicable, RD regular diet, RR risk ratio, SMD standardized mean difference, T2DM type 2 diabetes mellitus, VLCKD very low-calorie ketogenic diet