title: Metabolic responses to high-fat or low-fat meals and association with sympathetic nervous system activity in healthy young men.
abstract: 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 3.5 h after a high-fat (70%, energy from fat) or an isoenergetic low-fat (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.
authors.affiliation: Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Narumi
authors.initials: N
authors.lastname: Nagai
authors.forename: Naoki
authors.initials: N
authors.lastname: Sakane
authors.forename: Toshio
authors.initials: T
authors.lastname: Moritani
mesh_terms: D000328:Adult; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D004734:Energy Metabolism; D006339:Heart Rate; D006801:Humans; D050356:Lipid Metabolism; D008066:Lipolysis; D008297:Male; D009765:Obesity / Q000209:etiology / Q000503:physiopathology; D012119:Respiration; D012307:Risk Factors; D013057:Spectrum Analysis; D013564:Sympathetic Nervous System / Q000502:physiology*; D022722:Thermogenesis; D013997:Time Factors; D015430:Weight Gain
chemical_list: D004041:Dietary Fats