The Effectiveness of Intermittent Fasting to Reduce Body Mass Index and Glucose Metabolism: A Systematic Review and Meta-Analysis.

Journal of clinical medicine. 2019;8(10)

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Plain language summary

Calorie restriction (CR) is known to reduce body weight and to improve various cardiovascular risk factors. Due to the many difficulties in sustaining daily CR, intermittent fasting (IF) has been proposed as an alternative strategy for achieving and maintaining weight reduction. The aim of this study was to investigate the effectiveness of IF on weight loss and glucose metabolism by analysing the effect size of previous studies among the general population without diabetes mellitus. A total of 12 studies were included in this study. The total number of participants was 545 (261 in the intervention group and 284 in the control group). Study analysis indicates an improvement in glycaemic control and insulin resistance through IF diet as compared with a non-fasting control group. Lean mass was relatively conserved in the IF diet group however, no significant weight reduction was identified. Authors conclude that IF diet may improve fat distribution in the general population without chronic metabolic disease.


undefined: The effects of an intermittent fasting diet (IFD) in the general population are still controversial. In this study, we aimed to systematically evaluate the effectiveness of an IFD to reduce body mass index and glucose metabolism in the general population without diabetes mellitus. Cochrane, PubMed, and Embase databases were searched to identify randomized controlled trials and controlled clinical trials that compared an IFD with a regular diet or a continuous calorie restriction diet. The effectiveness of an IFD was estimated by the weighted mean difference (WMD) for several variables associated with glucometabolic parameters including body mass index (BMI) and fasting glucose. The pooled mean differences of outcomes were calculated using a random effects model. From 2814 studies identified through a literature search, we finally selected 12 articles (545 participants). Compared with a control diet, an IFD was associated with a significant decline in BMI (WMD, -0.75 kg/m ; 95% CI, -1.44 to -0.06), fasting glucose level (WMD, -4.16 mg/dL; 95% CI, -6.92 to -1.40), and homeostatic model assessment of insulin resistance (WMD, -0.54; 95% CI, -1.05 to -0.03). Fat mass (WMD, -0.98 kg; 95% CI, -2.32 to 0.36) tended to decrease in the IFD group with a significant increase in adiponectin (WMD, 1008.9 ng/mL; 95% CI, 140.5 to 1877.3) and a decrease in leptin (WMD, -0.51 ng/mL; 95% CI, -0.77 to -0.24) levels. An IFD may provide a significant metabolic benefit by improving glycemic control, insulin resistance, and adipokine concentration with a reduction of BMI in adults.

Lifestyle medicine

Fundamental Clinical Imbalances : Hormonal ; Structural
Patient Centred Factors : Triggers/Intermittent fasting
Environmental Inputs : Diet ; Nutrients
Personal Lifestyle Factors : Nutrition
Functional Laboratory Testing : Not applicable

Methodological quality

Allocation concealment : Not applicable
Publication Type : Journal Article