A 6-wk, double-blinded, placebo-controlled study was done to ascertain the effects of pyruvate supplementation (6 g/d) on body weight, body composition, and vigor and fatigue levels in healthy overweight Caucasian men and women. Twenty-six individuals were randomly assigned to a placebo group (seven men, seven women) and a pyruvate-supplemented group (three men, nine women). In addition, all subjects participated in a 3 d/wk exercise program, which consisted of a 45-60 min aerobic/anaerobic routine. After 6 wk of treatment, there was a statistically significant decrease in body weight (-1.2 kg, P<0.001), body fat (-2.5 kg, P<0.001), and percent body fat (23.0% pre versus 20.3% 6 wk post) in the pyruvate group. Furthermore, Profile of Mood States fatigue and vigor scores improved significantly for the pyruvate group (P<0.05) at 6 wk (vigor) and 4 and 6 wk (fatigue). There was no significant change in total lean body mass in the pyruvate group. The placebo group demonstrated a significant increase (P<0.05) for POMS vigor at 2 and 4 wk with no changes occurring in any of the remaining parameters measured. Thus, the ingestion of 6 g of pyruvate for 6 wk, in conjunction with mild physical activity, resulted in a significant decrease in body weight and fat mass.