Influence of dietary fatty acid composition and exercise on changes in fat oxidation from a high-fat diet

• Published in: Journal of applied physiology (1985) Vol. 109; no. 4; pp. 1011 - 1018
• Main Authors: COOPER, J. A, WATRAS, A. C, SHRIVER, T, ADAMS, A. K, SCHOELLER, D. A
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Physiological Society 01-10-2010
• Subjects: Adaptation, Physiological; Adolescent; Adult; Analysis of Variance; Bicycling; Biological and medical sciences; Body mass index; Cross-Over Studies; Diet; Dietary Fats - administration & dosage; Dietary Fats - metabolism; Energy Intake; Energy Metabolism; Exercise; Fatty acids; Fatty Acids - administration & dosage; Fatty Acids - metabolism; Fatty Acids, Monounsaturated - administration & dosage; Fatty Acids, Monounsaturated - metabolism; Fundamental and applied biological sciences. Psychology; Humans; Male; Middle Aged; Nitrogen - urine; Oils & fats; Oxidation; Oxidation-Reduction; Oxygen Consumption; Respiration; Sedentary Lifestyle; Studies; Time Factors; Young Adult; Physical exercise; stable isotopes; saturated fat; Lipids; Fatty acids; Feeding; Vertebrata; nonprotein respiratory exchange ratio; Mammalia; Diet; Saturated fatty acid; mono-unsaturated fat; Fat; Oxidation; Ratio; Isotopes
• ISSN: 8750-7587; 1522-1601; 1522-1601
• DOI: 10.1152/japplphysiol.01025.2009

Acute high-fat (HF) diets can lead to short-term positive fat balances until the body increases fat oxidation to match intake. The purpose of this study was to examine the effects of a HF diet, rich in either mono-unsaturated or saturated fatty acids (FAs) and exercise, on the rate at which the body adapts to a HF diet.(13)C-labeled oleate and (2)H-labeled palmitate were also given to determine the contribution of exogenous vs. global fat oxidation. Eight healthy men (age of 18-45 yr; body mass index of 22 ± 3 kg/m(2)) were randomized in a 2 × 2 crossover design. The four treatments were a high saturated fat diet with exercise (SE) or sedentary (SS) conditions and a high monounsaturated fat diet with exercise (UE) or sedentary (US) conditions. Subjects stayed for 5 days in a metabolic chamber. All meals were provided. On day 1, 30% of energy intake was from fat, whereas days 2-5 had 50% of energy as fat. Subjects exercised on a stationary cycle at 45% of maximal oxygen uptake for 2 h each day. Respiratory gases and urinary nitrogen were collected to calculate fat oxidation. Change from day 1 to day 5 showed both exercise treatments increased fat oxidation (SE: 76 ± 30 g, P = 0.001; UE: 118 ± 31 g, P < 0.001), whereas neither sedentary condition changed fat oxidation (SS: -10 ± 33 g, P = not significant; US: 41 ± 14 g, P = 0.07). No differences for dietary FA composition were found. Exercise led to a faster adaptation to a HF diet by increasing fat oxidation and achieving fat balance by day 5. Dietary FA composition did not differentially affect 24-h fat oxidation.