Background: Visceral fat area is most closely associated with the metabolic syndrome. Computed tomography (CT) and visceral fat meters are available as a means of measuring visceral fat area. CT scans are the gold standard for measuring visceral fat area, but since making the measurements is complicated and limited to measuring facilities, and there is X-ray exposure, they cannot be applied to large numbers of subjects as in medical checkups. The InBody 430 body composition analyzer uses direct segmental multifrequency bioelectrical impedance analysis (DSM-BIA); its design provides increased reproducibility and enables accurate, highly precise measurements. In addition, it may be possible to predict visceral fat area as a function of abdominal girth or of BMI and percent body fat. Moreover, visceral fat area is expected to be related to age and sex.
Objectives: The purpose of this study was to estimate visceral fat area on the basis of percent body fat measured with the InBody analyzer, age, and anthropometric parameters.
Methods: A total of 457 (119 male and 338 female) participants were recruited from two towns with quite different environments in Mie Prefecture. Their height, weight, abdominal girth, body composition, and visceral fat area were measured. Body composition was measured with an eightpolar bioelectric impedance analyzer, and visceral fat area was measured with a visceral fat meter. A prediction equation for estimating visceral fat area was obtained by multiple linear regression analysis. Visceral fat area was used as the dependent variable, and age and percent body fat × (abdominal girth)2 were used as the independent variables.
Results: The visceral fat area, abdominal girth, and BMI values of the female participants were skewed in the smaller direction, and their age distribution showed a peak in the 20s-30s age range and in the 60s-70s age range. The percent body fat values of the female participants yielded an almost perfect bell-shaped curve. The distribution of the visceral fat area values of the male participants did not describe a clear bell-shaped curve, but the distributions of their percent body fat values and abdominal girth values yielded almost perfect bell-shaped curves. The ages of the male participants showed a peak in the 20s-30s range and in the 60s-70s range, and the distribution of their BMI values was skewed in the smaller direction. Of the parameters tested, percent body fat × (abdominal girth)2 showed the highest correlation coefficient with visceral fat area. Multiple regression gave the prediction equations to estimate visceral fat area using age and percent body fat × (abdominal girth)2; their coefficients of determination (R2) were 0.763 and 0.875 in male and female participants, respectively.
Conclusion: Visceral fat area can be estimating using the formula obtained based on data that have been acquired with an existing body composition analyzer.
Objectives: This study aimed to investigate the substrate metabolism response to moderateand high-intensity equicaloric exercises in endurance-trained men.
Methods: Ten male endurance-trained runners (mean ± standard error: age, 22 ± 1 years; body mass index, 19.3 ± 0.7 kg/m2; ⩒O2max, 64.1 ± 2.1 mL/kg/min) performed a graded exercise test on a treadmill to determine the exercise intensity at which elicits maximal fat oxidation (Fatmax) and subsequently completed two equicaloric exercises (53 min at Fatmax and 30 min at 65％⩒O2max). Substrate oxidation rates during exercise and 2-h post-exercise recovery period were determined using indirect calorimetry. Blood samples were collected before exercise; immediately post-exercise; and at 30 min, 1 h, and 2 h post-exercise to determine plasma noradrenaline, serum growth hormone (GH), and free fatty acid (FFA) concentrations.
Results: Mean Fatmax was observed at 37.3 ± 4.6 ％⩒O2max. Fat oxidation volume during exercise was significantly higher in the Fatmax trial than in the 65％⩒O2max trial (15.2 ± 1.5 g vs 8.5 ± 0.7 g, P ＜ 0.01). No significant difference in fat oxidation occurred in the post-exercise recovery period. Serum GH and plasma noradrenaline concentrations were higher at 65％⩒O2max than at Fatmax immediately post-exercise (P ＜ 0.05). However, there was no difference in serum FFA levels between exercise intensities.
Conclusions: Exercise at Fatmax oxidized more fat than exercise at 65％⩒O2max when matched for energy expenditure during exercise in endurance-trained men.