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

Abstract

Cooper JA, Watras AC, Shriver T, Adams AK, Schoeller DA. Influence of dietary fatty acid composition and exercise on changes in fat oxidation from a high-fat diet. J Appl Physiol 109: 1011-1018, 2010. First published July 22, 2010; 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 monounsaturated 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 Ϯ 3 kg/m 2 ) were randomized in a 2 ϫ 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 Ϯ 30 g, P ϭ 0.001; UE: 118 Ϯ 31 g, P Ͻ 0.001), whereas neither sedentary condition changed fat oxidation (SS: Ϫ10 Ϯ 33 g, P ϭ not significant; US: 41 Ϯ 14 g, P ϭ 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. saturated fat; mono-unsaturated fat; nonprotein respiratory exchange ratio; stable isotopes THE PREVALENCE OF OBESITY continues to be a leading public health concern in the United States with approximately twothirds of the adult population being classified as overweight or obese (18). The development of obesity is by definition an accumulation of excess body fat due to positive energy balance. This is generally assumed to be caused by periods of positive energy balance resulting in the storage of fat but can also occur from short periods of positive fat balance even under eucaloric feeding conditions if, as hypothesized by Flatt, the weak human leptin system is overpowered by the stronger carbohydrate balance system leading to positive energy balance during the days following the period of positive fat balance (5). We and others have studied conditions that lead to a short-term positive fat balance and have shown that a shift to a high-fat (HF) diet from an average fat diet is not accompanied by an immediate increase in fat oxidation that would match the rate of fat intake even when the diets are eucaloric (6,27,28). The rate of fat oxidation increases only slowly with time, and thus it ca...

Effects of Intermittent Physical Activity on Fat Utilization over a Whole Day

“…Previous studies have reported that higher PAL induces greater fat utilization when switching from an HC to an HF meal (3,10,26,30). These studies showed results consistent with the International Association for the Study of Obesity consensus statement.…”

“…In addition, the duration of the experiment was shorter than previous studies. Previous studies have monitored fat adaptation over a 4-d period (3,10,30). However, participants in the present study consumed HC food that contained 70% CHO (FQ = 0.928, higher than in previous studies) for 2 d before entering the chamber to detect subsequent differences in adaptation speed to an HF diet.…”

Short-term low carbohydrate/high-fat diet intake increases postprandial plasma glucose and glucagon-like peptide-1 levels during an oral glucose tolerance test in healthy men

“…Because a LC/HFD contains little carbohydrate, it reduces blood glucose availability and glucose oxidation gradually decreases. In contrast, fat oxidation gradually increases 12,13,16 and the contribution of TG-derived fatty acid oxidation to total fat oxidation increases with a LC/HFD. 37 The increased contribution of TG-derived fatty acid oxidation is involved in the increase in lipoprotein lipase (LPL) activity in the muscle capillary bed with high-fat diet.…”

“…Short-term exposure (1-11 days) to LC/HFD decreases carbohydrate oxidation [10][11][12][13][14][15][16] and increases endogenous glucose production. 10,17 In addition, shortterm LC/HFD (3-5 days) decreases insulin sensitivity, as measured using the hyperinsulinemic-euglycemic glucose clamp 18,19 and the intravenous glucose tolerance test.…”

Impact of exercise and dietary fatty acid composition from a high-fat diet on markers of hunger and satiety

“…We recently expanded upon our previous studies of the rate of adaptation (increasing fat oxidation to match a higher dietary fat intake) to a HF diet (Cooper et al, 2009; Cooper et al, 2010). This study was designed to test whether the fatty acid composition in the HF diet interacted with exercise to influence the rate of change in fat oxidation.…”