title: Influence of dietary fatty acid composition and exercise on changes in fat oxidation from a high-fat diet.
abstract: 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.
authors.affiliation: Department of Nutrition, Hospitality, and Retailing, Texas Tech University, Lubbock, Texas, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
authors.forename: A C
authors.initials: AC
authors.lastname: Watras
authors.forename: T
authors.initials: T
authors.lastname: Shriver
authors.forename: A K
authors.initials: AK
authors.lastname: Adams
authors.forename: D A
authors.initials: DA
authors.lastname: Schoeller
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001642:Bicycling; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise; D005227:Fatty Acids / Q000008:administration & dosage / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000652:urine; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D012119:Respiration; D057185:Sedentary Behavior; D013997:Time Factors; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D009584:Nitrogen