Effectiveness of intermittent fasting to potentiate weight loss or muscle gains in humans younger than 60 years old: a systematic review

The aim was to determinate if the intermittent fasting enhances weight loss or muscle gains in humans younger than 60 years old. Multiple databases were searched up to May 2020 for studies in English, using MeSH terms and text words relating intermittent fasting, weight loss and muscle gains. The protocol was registered in PROSPERO. Study quality was assessed using NICE methodology. A total of 10 original articles were evaluated. Eight papers collected data through randomised controlled trials and two from cross-sectional study. Intermittent fasting could be beneficial in resistance trained subjects or in overweight individuals to improve body composition by decreasing fat mass and at least maintain muscle mass; decrease in GLP-1 levels and; improving health-related biomarkers such glucose and insulin levels. However, future studies are needed in order to better elucidate the effect of intermittent fasting on body composition.