Effectiveness of an intermittent fasting diet versus continuous energy restriction on anthropometric measurements, body composition and lipid profile in overweight and obese adults: a meta-analysis

The effects of an intermittent fasting (IF) diet in the overweight or obese adult population are still controversial. This study aimed to evaluate the effectiveness of an IF diet to reduce anthropometric parameters (body mass index, body weight, and waist circumference), change body composition (fat mass, lean body mass and muscle mass) and lipid profile (total cholesterol, HDL-c, LDL-c and triglycerides), and to adhere to the diet in comparison to continuous energy restriction (CER) in overweight or obese adults. A research question PICO (patients, intervention, comparison, outcome) was established. PubMed, Scopus, Web of Science, Cochrane, and Scielo databases were searched to identify randomized clinical trials that compared an IF diet with a CER diet or a regular diet. DeCS and MeSH descriptors and Boolean operators (AND and OR) were used. From 859 studies identified through the literature search, 18 articles were finally selected. Overall, IF diets were associated with higher weight loss in four studies and similar reduction in waist circumference in one study, compared with a CER regimen. Fat mass tended to decrease more in the IF groups in five studies. However, the lean and muscle mass loss was similar in both groups. Only three studies observed significant differences in lipid profile variables, mostly in the IF groups. Adherence to the diet was inconclusive. An IF diet may provide a benefit by improving anthropometry, body composition, and lipid profile in overweight or obese adult population, likewise a CER diet.