Effects of Paleolithic Diet on Glucose Control in Adults: A Systematic Review and Meta-analysis of Controlled Clinical Trials

Background: Although the results were conflicting, the Paleolithic diet (PD) was proposed to be effective in improvement of metabolic status. We aimed to conduct a systematic review and meta-analysis on the randomized controlled clinical trials (RCTs) evaluating the effects of PD on glycemic markers. Methods: Online databases such as PubMed, Scopus, Web of Science, and Google Scholar were searched up to December 2017 without any restrictions. The weighted mean difference (WMD) was also calculated using random effects model. Results: Eventually, eight good quality studies were included in the present systematic review and meta-analysis. The pooled analysis showed that although adherence to the PD led to reduction of fasting blood glucose (FBG) concentrations, it was no statistically significant (WMD = -0.31, 95% CI: -0.70, 0.07, P = 0.11). Moreover, compared with the control diets, the PD consumption did not significantly affect other glycemic markers such as 2-h post-prandial blood glucose (2h PBG), insulin, homeostasis model assessment for insulin resistance (HOMA-IR), and Hemoglobin A1c (HbA1c). Conclusions: Adherence to the PD had no significant effect on the glycemic markers, but reduction was observed in FBG levels.