Reply to Letter to the editor regarding "The effect of pistachio supplementation on metabolic syndrome and its components in adults: a systematic review and meta-analysis of randomized controlled trials"

Two researchers (F.B and S.K.F.-P.) reviewed the abstracts and titles of all of the acknowledged research to determine whether it was eligible for inclusion in the present meta-analysis according to the inclusion criteria. The authors included all of the relevant available data from 17 articles on interventional studies. Regarding the objection raised about the effect size calculation, the inclusion of the various effect sizes from 1 study is a routine approach used in numerous meta-analyses, and their inclusion in the study did not impair the accuracy of the findings. The included studies were homogeneous in terms of intervention, outcomes, and participants, and the high rate of heterogeneity between the included studies for the majority of the study outcomes may have derived from the different characteristics of the participant populations, especially differences in their health status. As no study included in the review reported the correlation coefficient between the placebo conditions and the experimental conditions, the authors reanalyzed the data by inputting a moderate correlation coefficient of 0.5. Our study showed that pistachio consumption has a positive effect in terms of reducing the components of metabolic syndrome. In conclusion, this study reanalyzed the data and justified the methods used for showing the positive effect of pistachio consumption on metabolic syndrome components, and the potential for further research to identify the underlying mechanisms and the effects on various populations. The study's protocol was registered, and Comprehensive Meta-Analysis software was used in the statistical analyses. The authors recommend further research to investigate the potential effect of the consumption of pistachios.