The relationship between pistachio (Pistacia vera L) intake and adiposity: A systematic review and meta-analysis of randomized controlled trials.

Background: The aim of the study was to conduct a systematic review to comprehensively evaluate the relationship between pistachio intake and obesity. Methods: We searched 6 databases and acquired parameters from randomized controlled trials regarding obesity, including body weight, body mass index (BMI), and waist circumference. A fixed-effect model was applied to the meta-analysis for the weighted mean difference (WMD) between a diet with pistachios and a control diet. Results: Eleven trials including a total of 1593 subjects met the inclusion criteria. Compared to the group on a control diet, the pistachio diet group showed lower BMI values (WMD: -0.18 kg/m(2); 95% confidence interval [CI]: -0.26, -0.11 kg/m(2);I-2 = 29.8%) and no differences in body weight (WMD: -0.22 kg; 95% CI: -0.50, 0.07 kg;I-2 = 0.0%) or waist circumference (WMD: 0.76 cm; 95% CI: -0.11, 1.63 cm;I-2 = 7.0%). Conclusion: A diet with pistachios reduced BMI and had no significant effects on body weight and waist circumference.