2005 年 51 巻 5 号 p. 355-360
The present study was designed to investigate the metabolic and sympathetic responses to a high-fat meal in humans. Fourteen young men (age: 23.6±0.5 y, BMI: 21.3±0.4 kg/m2) were examined for energy expenditure and fat oxidation measured by indirect calorimetry for 3.5h after a high-fat (70% energy from fat) or an isoenergetic lowfat (20% energy from fat) meal served in random order. The sympathetic nervous system (SNS) activity was assessed using power spectral analysis of heart rate variability (HRV). After the high-fat meal, increases in thermoregulatory SNS activity (very low-frequency component of HRV, 0.007-0.035 Hz, 577.4±45.9 vs. 432.0±49.3 ms2, p<0.05) and fat oxidation (21.0±5.3 vs. 13.3±4.3 g, p<0.001) were greater than those after the low-fat meal. However, thermic effects of the meal (TEM) were lower after the high-fat meal than after the low-fat meal (27.5±11.2 vs. 36.1±10.9 kcal, p<0.05). In conclusion, the high' fat meal can stimulate thermoregulatory SNS and lipolysis, but resulted in lower TEM, suggesting that a high proportion of dietary fat intake, even with a normal daily range of calories, may be a potent risk factor for further weight gain.
