Table 2. Summary of Significant Associations of Intermittent Fasting With Health Outcomes.
Source | Outcome | Population | Duration of fasting | Type of IF | Control | No. of studies | Sample size (IF/control) | Metric | Random effect size (95% CI) | P value | I2, % | GRADE rating | AMSTAR-2 rating |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Anthropometric measures | |||||||||||||
Cui et al,25 2020 | BMI | Healthy adults, some with overweight, obesity, or NAFLD | 1-2 mo | MADF | RD | 4 | 82/54 | MD | −1.20 (−1.44 to −0.96) | <.001 | 0 | High | Low |
Park et al,28 2020 | BMI | Adults with overweight or obesity | 2-3 mo | MADF | RD, CER, or TRE | 8 | 307/298 | MD | −0.80 (−1.17 to −0.43) | <.001 | 48.4 | Low | Moderate |
Park et al,28 2020 | BMI | Adults with overweight or obesity | 2-6 mo | MADF | RD, CER, or TRE | 9 | 374/366 | MD | −0.73 (−1.13 to −0.34) | .001 | 53.2 | Very low | Moderate |
He et al,27 2021 | Body weight, kg | Adults with overweight or obesity | 2-3 mo | MADF | CER | 2 | 39/39 | MD | −1.65 (−2.73 to −0.58) | .003 | 0 | Moderate | Moderate |
He et al,27 2021 | Body weight, kg | Adults with overweight or obesity with no comorbidities | 2-6 mo | MADF | CER | 3 | 73/73 | MD | −1.42 (−2.44 to −0.41) | .006 | 0 | Moderate | Moderate |
Park et al,28 2020 | Body weight, kg | Adults with overweight, some with NAFLD | 1-3 mo | MADF | CER, TRE, or RD | 8 | 307/299 | MD | −1.77 (−3.19 to −0.34) | .02 | 55.5 | Very low | Moderate |
He et al,27 2021 | Body weight, kg | Adults with overweight or obesity, some with diabetes | 3 mo | 5:2 diet | RD or CER | 3 | 117/173 | MD | −1.67 (−2.79 to −0.55) | .003 | 0 | Very low | Moderate |
Pellegrini et al,26 2020 | Body weight, kg | Normal weight healthy male adults, some with prediabetes | 1-2 mo | TRE 12-24 h | RD or CER | 5 | 44/41 | MD | −0.38 (−0.71 to −0.04) | .03 | 0 | Low | Low |
He et al,27 2021 | Fat-free mass, kg | Adults with obesity | 2-6 mo | MADF | CER | 3 | 73/73 | MD | −0.70 (−1.38 to −0.02) | .04 | 0 | Moderate | Moderate |
Cui et al,25 2020 | Fat-free mass, kg | Healthy adults, some with overweight or obesity | 1-12 mo | MADF | RD | 5 | 89/73 | MD | −1.38 (−2.26 to −0.49) | .002 | 91.0 | Low | Low |
Park et al,28 2020 | Fat mass, kg | Adults with overweight or obesity | 1-2 mo | 0-calorie ADF | RD or CER | 2 | 39/39 | MD | −1.99 (−2.59 to −1.38) | <.001 | 0 | Moderate | Moderate |
He et al,27 2021 | Fat mass, kg | Adults with obesity | 2-6 mo | MADF | CER | 3 | 73/73 | MD | −1.05 (−1.98 to −0.13) | .03 | 0 | Very low | Moderate |
Park et al,28 2020 | Fat mass, kg | Adults with overweight or obesity, some with NAFLD | 2-3 mo | MADF | RD, CER, or TRE | 5 | 233/225 | MD | −1.08 (−1.91 to −0.26) | .01 | 31.7 | Very low | Moderate |
Cui et al,25 2020 | Fat mass, kg | Healthy adults, some with overweight or obesity | 1-12 mo | MADF | RD | 6 | 119/107 | MD | −4.96 (−8.08 to −1.85) | .002 | 99.0 | Very low | Low |
Park et al,28 2020 | Fat mass, kg | Adults with overweight or obesity, some with NAFLD | 2-6 mo | MADF | RD, CER, or TRE | 6 | 300/293 | MD | −0.96 (−1.91 to −0.004) | .049 | 43.0 | Very low | Moderate |
Moon et al,5 2020 | Fat mass, kg | Adults with overweight or obesity | 2-3 mo | TRE 12-21 h | RD | 3 | 112/96 | MD | −2.40 (−2.98 to −1.82) | <.001 | 0 | Low | Moderate |
Lipid profile | |||||||||||||
Meng et al,7 2020 | LDL-C, mg/dL | Adults with normal weight, overweight, or obesity | 3-12 mo | MADF | RD with exercise | 5 | 139/140 | MD | −5.14 (−7.44 to −2.83) | <.001 | 0 | Very low | Moderate |
Meng et al,7 2020 | LDL-C, mg/dL | Adults with normal weight, overweight, or obesity | 2-12 mo | MADF | RD with exercise | 7 | 156/154 | MD | −5.23 (−7.52 to −2.94) | <.001 | 0 | Very low | Moderate |
Park et al,28 2020 | TC, mg/dL | Adults with overweight or obesity, some with NAFLD | 2-3 mo | MADF | RD, CER, or TRE | 5 | 250/241 | MD | −10.95 (−18.98 to −2.93) | .007 | 2.7 | Very low | Moderate |
Park et al,28 2020 | TC, mg/dL | Adults with overweight or obesity, some with NAFLD | 2-6 mo | MADF | RD or CER | 6 | 317/309 | MD | −8.13 (−15.79 to −0.46) | .04 | 19.9 | Very low | Moderate |
Meng et al,7 2020 | TG, mg/dL | Adults with overweight or obesity with no comorbidities | 2 mo | MADF | RD or RD with exercise | 2 | 17/14 | MD | −26.84 (−52.33 to −1.35) | .04 | 0 | Low | Moderate |
Park et al,28 2020 | TG, mg/dL | Adults with overweight or obesity, some with NAFLD | 2-3 mo | MADF | RD, CER, or TRE | 5 | 250/241 | MD | −21.67 (−39.44 to −3.89) | .02 | 0 | Very low | Moderate |
Glycemic profile | |||||||||||||
Pellegrini et al,26 2020 | FPG, mg/dL | Healthy adults, some with overweight, obesity, or chronic diseases | 1-2 mo | TRE 12-24 h | RD or CER | 4 | 57/56 | MD | −2.45 (−4.72 to −0.18) | .04 | 0 | Very low | Low |
Pureza et al,8 2020 | FPG, mg/dL | Adults with overweight | 4 d to 3 mo | TRE 12-21 h | RD or TRE 12-15 h | 7 | 148/147 | MD | −2.75 (−4.6 to −0.91) | .003 | 88.7 | Very low | Moderate |
He et al,27 2021 | Fasting insulin, mIU/mL | Female adults with overweight or obesity | 3-6 mo | 5:2 diet | CER | 2 | 90/94 | MD | −1.00 (−1.77 to −0.39) | .002 | 0 | Moderate | Moderate |
Pureza et al,8 2020 | HOMA-IR | Healthy adults; some with overweight, obesity, or prediabetes | 1 d to 2 mo | TRE 18 h | RD | 4 | 59/60 | MD | −0.51 (−0.82 to −0.19) | .002 | 50.8 | Very low | Moderate |
Blood pressure | |||||||||||||
Cui et al,25 2020 | SBP, mmHg | Healthy adults, some with overweight or obesity | 1-12 mo | MADF | RD | 4 | 90/85 | MD | −4.42 (−7.35 to −1.49) | .003 | 84.0 | Very low | Low |
Cui et al,25 2020 | DBP, mmHg | Healthy adults, some with overweight or obesity | 1-12 mo | MADF | RD | 4 | 90/85 | MD | −3.41 (−5.91 to −0.92) | .003 | 80.0 | Very low | Low |
Abbreviations: AMSTAR-2, A Measurement Tool to Assess Systematic Reviews; BMI, body mass index; CER, continuous energy restriction; DBP, diastolic blood pressure; FPG, fasting plasma glucose; HOMA-IR, homeostatic model assessment of insulin resistance; IF, intermittent fasting; LDL-C, low-density lipoprotein cholesterol; MADF, modified alternate-day fasting; MD, mean difference; NAFLD, nonalcoholic fatty liver disease; RD, regular diet; SBP, systolic blood pressure; TC, total cholesterol; TG, triglycerides; TRE, time-restricted eating.