Effect of fennel supplementation along with high-protein, low-carbohydrate weight-loss diet on insulin resistance and percentage of fat and muscle mass in overweight/obese women with polycystic ovary syndrome

[Display omitted] •Polycystic syndrome (PCOS) is an endocrine hormones disorder can leads to obesity.•The effect of HP diet with fennel on IR and body composition were assessed in PCOS.•Weight loss is effective treatment of IR and improvement of body composition in PCOS.•Fennel supplement had no beneficial effect on insulin resistance, body fat or muscle. The aim of this study was investigated the effects of fennel supplementation with energy-restricted diets on body fat and muscle percentage and insulin resistance in women with PCOS. Sixty-four overweight/obese women with PCOS were randomly allocated to 4 groups for 12 weeks as follows: (1) standard diet + fennel (SDF), (2) high-protein, low-carbohydrate diet supplemented with fennel (HPF), (3) standard diet + placebo (SDP), and (4) high-protein, low-carbohydrate diet + placebo (HPP). After 12 weeks of intervention, there were significant changes in the percentage of body fat and muscle in all groups. Decreasing in fasting insulin was −4.12 micIU/ml (P = 0.01) for HPF and −4.5 micIU/ml (P = 0.03) for SDP groups. In addition, HOMA-IR significantly decreased in HPF (P = 0.02) and SDP (P = 0.02) groups. Energy-restricted diets independent of dietary composition improved the body fat and muscle percentage and insulin resistance indices in women with PCOS. High-protein diet and fennel compared with standard diet and placebo had no significant effect on insulin resistance, body fat and muscle.