comparison of the effect of a low-carbohydrate diet with a low-fat diet on anthropometric indices and body fat percentage: a systematic review and meta-analysis of randomized controlled trials

Background: although many studies have been conducted to compare the effect of adherence to a low-carbohydrate diet (lcd) with a low-fat diet (lfd) on anthropometric indices and body fat percentage, there is still no definite conclusion in this regard. therefore, the present study aims to summarize results of studies comparing a lfd and a lcd on weight loss. methods: a systematic search of databases including pubmed, scopus, and cochran library was performed up to november 2020. all randomized controlled trials (rcts) comparing the effect of adherence to a lcd with a lfd on anthropometric indices and body fat percentage were included. search results were limited to english-language publications. sixty-three rcts, including 7660 participants, were selected for the present study. results: pooled analysis indicated that adherence to lcd was significantly associated with a greater reduction in bmi (smd = - 0.07, 95% ci: -0.14,-0.001; p = 0.04), weight (kg) (smd = - 0.22, 95% ci: - 0.31, - 0.12; p ≤ 0.001), and percentage of body fat mass (smd = - 0.28, 95% ci: -0.48, - 0.08; p = 0.006) compared to lfd. however, no significant difference in changes of kilogram of body fat mass and waist circumference was observed between the two diet programs. conclusion: overall, adhering to lcd was more effective than lfd in losing weight and body fat percentage.