The aim of this study was to investigate responses of ghrelin, leptin, and adiponectin to a weight reduction period of 10 weeks in male subjects with high lean body mass and low body fat values. Fourteen male bodybuilders (7 competitors: 28.3 +/- 10.3 years, 175.3 +/- 5.4 cm, 82.2 +/- 9.3 kg; 7 controls: 22.4 +/- 3.0 years, 182.4 +/- 6.9 cm, 85.3 +/- 10.5 kg) participated in this study. The subjects were tested 3 times: 11 weeks (TEST1), 5 weeks (TEST2), and 3 days (TEST3) before the national championships. Testing procedure included dual-energy x-ray absorptiometry scan; calculation of daily energy intake and expenditure; and venous blood sampling for fasting ghrelin, leptin, and adiponectin. In the competitors' group, a significant (P < .05) 4.1-kg loss of body fat was observed that resulted in 6.5% +/- 1.5% of the body fat at the end of the study. Ghrelin increased significantly by 20.4% by TEST2. By TEST3, ghrelin was further increased by 6% (P > .05). The pattern of leptin was opposite, with a significant 27.7% decrease at TEST2 and no further decrease at TEST3 (P > .05). No significant change was observed in adiponectin concentration during the study. In the control group, no significant changes in biochemical parameters were observed. In conclusion, ghrelin concentration significantly increases, but is suppressed in conditions of limited energy availability that is accompanied by significant body mass loss in male subjects with initial low body fat values.