This study was to clarify the effects of exercise regimen on body weight reduction by food delivery for overweight men and women. Subjects were overweight adults who were selected as to the criterion of 15% over a stanard body weight [(Stature-100)×0.9]. They were divided into (a) training group (n=7) and (b) control group (n=14) on the basis of Vo_2 max. Diets provided were 1400 kcal/day for males and 1200kcal/day for females by food delivery. Training group was engaged in 5 weeks exercise program which consisted of bicycle ergometer exercise of 30 minutes for six days per week. No significant difference was found in body weight reduction between training and control groups. Fat weight loss, however, in training group was greater than that of control group. On the other hand, there was a greater decrease in LBM for control group. Maximal oxygen intake (ml/min) in training group was kept constant throughout 5 weeks, while a significant decrease was found in control group. Exhaustion time was tended to increase in training group, while it was significantly decreased in control group. It was concluded that calory restricution by food delivery for overweight adults was effective to reduce body weight, and that an aerobic exercise program combined with a weight-reducing dietary regimen not only produced a greater loss of fat, but also prevented decrease of maximal aerobic power compared to a dietary regimen alone.