title: Activity energy expenditure is a major determinant of dietary fat oxidation and trafficking, but the deleterious effect of detraining is more marked than the beneficial effect of training at current recommendations.
abstract: BACKGROUND
  Previous studies suggested that physical activity energy expenditure (AEE) is a major determinant of dietary fat oxidation, which is a central component of fat metabolism and body weight regulation.
  
  
  OBJECTIVE
  We tested this hypothesis by investigating the effect of contrasted physical activity levels on dietary saturated and monounsaturated fatty acid oxidation in relation to insulin sensitivity while controlling energy balance.
  
  
  METHODS
  Sedentary lean men (n = 10) trained for 2 mo according to the current guidelines on physical activity, and active lean men (n = 9) detrained for 1 mo by reducing structured and spontaneous activity. Dietary [d31]palmitate and [1-¹³C]oleate oxidation and incorporation into triglyceride-rich lipoproteins and nonesterified fatty acid, AEE, and muscle markers were studied before and after interventions.
  
  
  RESULTS
  Training increased palmitate and oleate oxidation by 27% and 20%, respectively, whereas detraining reduced them by 31% and 13%, respectively (P < 0.05 for all). Changes in AEE were positively correlated with changes in oleate (R² = 0.62, P < 0.001) and palmitate (R² = 0.66, P < 0.0001) oxidation. The d31-palmitate appearance in nonesterified fatty acid and very-low-density lipoprotein pools was negatively associated with changes in fatty acid translocase CD36 (R² = 0.30), fatty acid transport protein 1 (R² = 0.24), and AcylCoA synthetase long chain family member 1 (ACSL1) (R² = 0.25) expressions and with changes in fatty acid binding protein expression (R² = 0.33). The d31-palmitate oxidation correlated with changes in ACSL1 (R² = 0.39) and carnitine palmitoyltransferase 1 (R² = 0.30) expressions (P < 0.05 for all). Similar relations were observed with oleate. Insulin response was associated with AEE (R² = 0.34, P = 0.02) and oleate (R² = 0.52, P < 0.01) and palmitate (R² = 0.62, P < 001) oxidation.
  
  
  CONCLUSIONS
  Training and detraining modified the oxidation of the 2 most common dietary fats, likely through a better trafficking and uptake by the muscle, which was negatively associated with whole-body insulin sensitivity.
authors.affiliation: Institut Pluridisciplinaire Hubert Curien, Centre National de la Recherche Scientifique UMR 7178, Université de Strasbourg, Strasbourg, France. audrey.bergouignan@ucdenver.edu
authors.forename: Audrey
authors.initials: A
authors.lastname: Bergouignan
authors.forename: Iman
authors.initials: I
authors.lastname: Momken
authors.forename: Etienne
authors.initials: E
authors.lastname: Lefai
authors.forename: Edwina
authors.initials: E
authors.lastname: Antoun
authors.forename: Dale A
authors.initials: DA
authors.lastname: Schoeller
authors.forename: Carine
authors.initials: C
authors.lastname: Platat
authors.forename: Isabelle
authors.initials: I
authors.lastname: Chery
authors.forename: Alexandre
authors.initials: A
authors.lastname: Zahariev
authors.forename: Hubert
authors.initials: H
authors.lastname: Vidal
authors.forename: Laure
authors.initials: L
authors.lastname: Gabert
authors.forename: Sylvie
authors.initials: S
authors.lastname: Normand
authors.forename: Damien
authors.initials: D
authors.lastname: Freyssenet
authors.forename: Martine
authors.initials: M
authors.lastname: Laville
authors.forename: Chantal
authors.initials: C
authors.lastname: Simon
authors.forename: Stephane
authors.initials: S
authors.lastname: Blanc
mesh_terms: D000106:Acetate-CoA Ligase / Q000378:metabolism; D000328:Adult; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D004041:Dietary Fats / Q000378:metabolism*; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D050612:Fatty Acid Transport Proteins / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D015227:Lipid Peroxidation; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008297:Male; D019301:Oleic Acid / Q000378:metabolism*; D010084:Oxidation-Reduction; D010168:Palmitates / Q000378:metabolism*; D057185:Sedentary Behavior; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D050612:Fatty Acid Transport Proteins; D050556:Fatty Acid-Binding Proteins; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D008079:Lipoproteins, VLDL; D010168:Palmitates; D019301:Oleic Acid; D002334:Carnitine O-Palmitoyltransferase; D000106:Acetate-CoA Ligase