Introduction: Limited studies have been conducted on the effect of whey protein during endurance training on fat mass, plasma lipoprotein and hormonal changes in obese people. The aim of this study was to investigate the effects of endurance training combined with whey protein supplementation on serum Leptin, Testosterone to Cortisol ratio, Lipid profile and body composition in obese male students.

Methods: 26 obese volunteered male were randomly divided into two groups of supplement and placebo. Both groups performed the same endurance training (4 sessions in week for 8 weeks) and each group was given either whey protein or placebo in a double blind manner to be taken orally for eight weeks (1.8g/kg/day). Fasting blood samples were taken before the training protocol and 36 hour after last training session. Changes from baseline were assessed using paired t-test and to compare between groups independent t-tests was used.

Results: Results showed that there was a significant difference in body weight (supplementation: 89.7±4.3, Placebo: 91.2±4.6)(p=0.004), fat mass (supplementation: 23.9±3.8, Placebo:­27.2±4.1) (p=0.001), body fat percentage (supplementation: 26.6±3.8, Placebo:29.8±4.9) (p=0.001), HDL-c (supplementation: 47.8±4.2, Placebo:­ 41.5±4.4) (p=0.000), TG (supplementation: 201.3±11.2, Placebo: 210.6±13.7) (p=0.000) and testosterone (supplementation: 6.2±0.6, Placebo:5.8±0.8) (p=0.02) between the two groups.

Conclusion: Eight weeks whey protein supplementation and endurance exercise training lead to a greater reduction of subcutaneous fat and blood lipids, and also increase in HDL and Testosterone concentration.