The effects of intermittent fasting on body composition and cardiometabolic health in adults with prediabetes or type 2 diabetes: A systematic review and meta-analysis

AimTo perform a meta-analysis to investigate the effects of intermittent fasting (IF), as compared with either a control diet (CON) and/or calorie restriction (CR), on body composition and cardiometabolic health in individuals with prediabetes and type 2 diabetes (T2D).MethodsPubMed, Web of Science, and Scopus were searched from their inception to March 2024 to identify original randomized trials with parallel or crossover designs that studied the effects of IF on body composition and cardiometabolic health. Weighted mean differences (WMDs) or standardized mean differences with 95% confidence intervals (CIs) were calculated using random-effects models.ResultsOverall, 14 studies involving 1101 adults with prediabetes or T2D were included in the meta-analysis. IF decreased body weight (WMD -4.56 kg [95% CI -6.23 to -2.83]; p = 0.001), body mass index (BMI; WMD -1.99 kg.m2 [95% CI -2.74 to -1.23]; p = 0.001), glycated haemoglobin (HbA1c; WMD -0.81% [95% CI -1.24 to -0.38]; p = 0.001), fasting glucose (WMD -0.36 mmol/L [95% CI -0.63 to -0.09]; p = 0.008), total cholesterol (WMD -0.31 mmol/L [95% CI -0.60 to -0.02]; p = 0.03) and triglycerides (WMD -0.14 mmol/L [95% CI -0.27 to -0.01]; p = 0.02), but did not significantly decrease fat mass, insulin, low-densitiy lipoprotein, high-density lipoprotein, or blood pressure as compared with CON. Furthermore, IF decreased body weight (WMD -1.14 kg [95% CI -1.69 to -0.60]; p = 0.001) and BMI (WMD -0.43 kg.m2 [95% CI -0.58 to -0.27]; p = 0.001), but did not significantly affect fat mass, lean body mass, visceral fat, insulin, HbA1c, lipid profiles or blood pressure.ConclusionIntermittent fasting is effective for weight loss and specific cardiometabolic health markers in individuals with prediabetes or T2D. Additionally, IF is associated with a reduction in body weight and BMI compared to CR, without effects on glycaemic markers, lipid profiles or blood pressure.