The Effect of Dried Glycyrrhiza Glabra L. Extract on Obesity Management with Regard to PPARγ2 (Pro12Ala) Gene Polymorphism in Obese Subjects Following an Energy Restricted Diet

Purpose: Obesity is a multifactorial health problem which results from the interaction of environmental and genetic factors. The aim of the present study was to determine the effects of dried licorice extract with a calorie restricted diet on anthropometric indices and insulin resistance with nutrigenetic approach. Methods: For this pilot, doubleblind, placebocontrolled randomized clinical trial, 72 eligible subjects were randomly allocated to Licorice or placebo group. They received a lowcalorie diet either with a 1.5 g/day of Licorice extract or placebo for 8 weeks. Results: There were no significant differences in anthropometric indices and dietary intake in genotype subgroups at the baseline. Findings indicated that supplementation with Licorice extract did not change anthropometric indices and biochemical parameters significantly compared to a hypocaloric diet alone. However, from the nutrigenetic point of view, significant changes in anthropometric indices and QUICKI were observed in the Pro12Pro genotypes compared to the Pro12Ala at the end of the study (p lt;0.05 in all variables). Moreover, no interactive effect of the Licorice supplement and Pro12Ala genotype was found. Conclusion: In obese subjects, the Pro/Pro polymorphism of the PPARγ2 gene seems to induce favourable effects on obesity management. Further studies are needed to clarify whether PPARγ2 gene polymorphisms or other obesity genes can affect responses to obesity treatment.