title: Effect of physical inactivity on the oxidation of saturated and monounsaturated dietary Fatty acids: results of a randomized trial.
abstract: OBJECTIVE
  Changes in the way dietary fat is metabolized can be considered causative in obesity. The role of sedentary behavior in this defect has not been determined. We hypothesized that physical inactivity partitions dietary fats toward storage and that a resistance exercise training program mitigates storage.
  
  
  METHODS
  We used bed rest, with randomization to resistance training, as a model of physical inactivity.
  
  
  METHODS
  The trial took place at the Space Clinic (Toulouse, France).
  
  
  METHODS
  A total of 18 healthy male volunteers, of mean age +/- standard deviation 32.6 +/- 4.0 y and body mass index 23.6 +/- 0.7 kg/m(2), were enrolled.
  
  
  METHODS
  An initial 15 d of baseline data collection were followed by 3 mo of strict bed-rest alone (control group, n = 9) or with the addition of supine resistance exercise training every 3 d (exercise group, n = 9).
  
  
  METHODS
  Oxidation of labeled [d(31)]palmitate (the main saturated fatty acid of human diet) and [1-(13)C]oleate (the main monounsaturated fatty acid), body composition, net substrate use, and plasma hormones and metabolites were measured.
  
  
  RESULTS
  Between-group comparisons showed that exercise training did not affect oxidation of both oleate (mean difference 5.6%; 95% confidence interval [95% CI], -3.3% to 14.5%; p = 0.20) and palmitate (mean difference -0.2%; 95% CI, -4.1% to 3.6%; p = 0.89). Within-group comparisons, however, showed that inactivity changed oxidation of palmitate in the control group by -11.0% (95% CI, -19.0% to -2.9%; p = 0.01) and in the exercise group by -11.3% (95% CI, -18.4% to -4.2%; p = 0.008). In contrast, bed rest did not significantly affect oleate oxidation within groups. In the control group, the mean difference in oleate oxidation was 3.2% (95% CI, -4.2% to 10.5%; p = 0.34) and 6.8% (95% CI, -1.2% to 14.7%; p = 0.08) in the exercise group.
  
  
  CONCLUSIONS
  Independent of changes in energy balance (intake and/or output), physical inactivity decreased the oxidation of saturated but not monounsaturated dietary fat. The effect is apparently not compensated by resistance exercise training. These results suggest that Mediterranean diets should be recommended in sedentary subjects and recumbent patients.
authors.affiliation: Institut Pluridisciplinaire Hubert Curien, Département d'Ecologie, Physiologie, et Ethologie, Strasbourg, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Bergouignan
authors.forename: Dale A
authors.initials: DA
authors.lastname: Schoeller
authors.forename: Sylvie
authors.initials: S
authors.lastname: Normand
authors.forename: Guillemette
authors.initials: G
authors.lastname: Gauquelin-Koch
authors.forename: Martine
authors.initials: M
authors.lastname: Laville
authors.forename: Timothy
authors.initials: T
authors.lastname: Shriver
authors.forename: Michel
authors.initials: M
authors.lastname: Desage
authors.forename: Yvon
authors.initials: Y
authors.lastname: Le Maho
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohshima
authors.forename: Claude
authors.initials: C
authors.lastname: Gharib
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blanc