Forty obese men (BMI 35-40 kg/m2,18-40 years of age) will be randomly assigned to one of four treatment interventions: 1) Calorie restricted; 2) Calorie restricted and HMB supplemented; 3) No calorie restriction; and 4) No calorie restriction and HMB-supplemented. Over the 8 week interventional period the calorie restricted group is expected to lose 3-5% of initial body weight. Anthropometric measures will be taken weekly, and dual energy x-ray absorptiometry (DXA) body composition and strength will be measured before and after 8-weeks of intervention. Blood and urine will be collected and analyzed at 0, 4, and 8 weeks. Additionally Dietary records and questionnaires concerning quality of life will be administered, and activity will be assessed using questionnaires and pedometers. Muscle biopsies will be taken before and after the 8-week study.