A study was conducted to investigate the influences of diet using supplemental foods and aerobic exercise on segmental body composition, body fat distribution and physical fitness in middle-aged women with intra-abdominal fat (IF) obesity. Twenty-five women were randomly divided into two treatment groups ; a group with a low-energy diet (D) and a group with D combined with exercise (DE). To ensure proper daily nutrition, the subjects were instructed to take every day a well-balanced supplemental food developed for very low-energy diets (170 kcal per pack). In addition to restricting energy intake, subjects from the DE group performed a bench-stepping exercise 3 days/wk for 75 min per session under in-hospital supervision. Whole-body fat mass (FM) and fat- and bone-free mass (FBFM) were assessed by dual energy x-ray absorptiometry. The intra-abdominal fat area (IFA) and subcutaneous fat area (SFA) were measured at the level of the umbilicus using computed tomography. Grip and leg extension strength, and maximal oxygen uptake were measured for evaluation of physical fitness. All assays and measurements were carried out before and after a 14-week intervention period. Weight and FM were significantly reduced in both the D (-7.7 kg and -5.8 kg, respectively) and DE (-8.9 kg and -7.3 kg, respectively) groups. All segmental FBFMs were significantly reduced in the D group, whereas FBFMs in the upper and lower limbs of the DE group remained unchanged. IFA and SFA were significantly reduced in both the D (-35 cm^2 and -48 cm^2) and DE (-32 cm^2 and -51 cm^2) groups. In the D group, changes in SFA were significantly and inversely correlated (r=-0.68) with initial values of IFA, but changes in IFA were not. Grip strength (+17%) and maximal oxygen uptake (+28%) were significantly increased in the DE group. No significant de-creases were found between any physical fitness variables in the D group. These results suggest that (1) the DE treatment possibly diminished the reduction in the FBFMs in the upper and lower limbs, and that (2) less SFA was reduced in the D group with much more IFA at the baseline. Moreover, the D treatment did not induce decreases in physical fitness in response to the weight loss.