Intermittent Fasting for the Prevention of Cardiovascular Disease Risks: Systematic Review and Network Meta-Analysis

Abstract

Context: While several studies have assessed the potential effect of intermittent fasting on reducing cardiovascular risks, the findings are inconclusive.

Objective: To compare the relative effectiveness of intermittent fasting methods in reducing key cardiovascular risks.

Methods: Studies were searched from Medline, Embase, Cochrane Library Central and Global Health to identify studies that enrolled adults (≥ 18 years) to intermittent fasting methods and reported effects on one of the six specified cardiovascular risk factors. We performed a random-effects network meta-analysis using a frequentist framework. Outcomes were reported as mean differences (MD) with their corresponding 95% confidence intervals (CI).

Results: Fifty-six studies were included in the analysis. With high certainty of evidence, modified alternate-day fasting was found to be the most effective intervention compared to a usual diet in reducing body weight (MD= -5.18 kg; 95% CI: -7.04, -3.32), waist circumference (-3.55 cm; -5.66, -1.45), systolic blood pressure (-7.24 mmHg; -11.90, -2.58), diastolic blood pressure (-4.70 mmHg; -8.46, -0.95). With high certainty, time-restricted eating was the most effective intervention compared to usual diet in reducing fat-free mass (-0.82 kg; -1.46, -0.17), waist circumference (-3.00 cm; -4.50, -1.51), diastolic blood pressure (-3.24 mmHg; -4.69, -1.79) and fasting plasma glucose (-3.74 mg/dL; -6.01, -1.46).

Conclusions: Modified alternate-day fasting, and time-restricted eating appear to be promising approaches for reducing most cardiovascular risk factors. These intermittent fasting methods may be considered as potential components of lifestyle interventions aimed at managing cardiovascular disease risk factors. However, further long-term randomised controlled trials comparing intermittent fasting methods are needed to confirm their efficacy and assess their safety over time.

Keywords: Cardiometabolic risk factors; Intermittent fasting; Network meta-analysis.

Fig. 1

The PRISMA study selection flow diagram

Fig. 2

Risk of bias (Summary)

Fig. 3

The summary of results network meta-analysis of intermittent fasting regimes (mean difference with 95% CI) in comparison with usual diet for all outcomes along with ranking by new GRADE certainty of evidence framework. Note: mADF = modified alternate day fasting; ADF = alternate day fasting; CER = continuous energy restriction; PF = periodic fasting; TRE time restricted eating

Fig. 4

Network plots of the direct comparisons between intermittent fasting interventions from head-to-head trials for the outcomes: (A) Weight; (B) Fat free mass; (C) Waist circumference; (D) LDL-cholesterol; (E) Systolic blood pressure; (F) Diastolic blood pressure; (G) Fasting plasma glucose. The sizes of nodes correspond to the number of participants randomized to the intermittent fasting methods and the width of line corresponds to the number of studies. Note: mADF = modified alternate day fasting; ADF = alternate day fasting; CER = continuous energy restriction; PF = periodic fasting; TRE time restricted eating

Fig. 5

Intermittent fasting network meta-analysis results (mean difference with 95% CI) with corresponding GRADE certainty of evidence for: Weight in kg (A); Fat-free mass in kg (B); Waist circumference in cm (C); Low density lipoprotein-LDL in mg/dL (D); Systolic blood pressure -SBP in mmHg (E); Diastolic blood pressure - DBP in mmHg (F); Fasting plasma glucose– FPG in mg/dL (G). Values in bold indicate a statistically significant effect. Colour coding indicates the GRADE certainty of evidence: green = high certainty, blue = moderate certainty. Note: mADF = modified alternate day fasting; ADF = alternate day fasting; CER = continuous energy restriction; PF = periodic fasting; TRE time restricted eating

Fig. 5

Intermittent fasting network meta-analysis results (mean difference with 95% CI) with corresponding GRADE certainty of evidence for: Weight in kg (A); Fat-free mass in kg (B); Waist circumference in cm (C); Low density lipoprotein-LDL in mg/dL (D); Systolic blood pressure -SBP in mmHg (E); Diastolic blood pressure - DBP in mmHg (F); Fasting plasma glucose– FPG in mg/dL (G). Values in bold indicate a statistically significant effect. Colour coding indicates the GRADE certainty of evidence: green = high certainty, blue = moderate certainty. Note: mADF = modified alternate day fasting; ADF = alternate day fasting; CER = continuous energy restriction; PF = periodic fasting; TRE time restricted eating