title: A decrease in physical activity affects appetite, energy, and nutrient balance in lean men feeding ad libitum.
abstract: BACKGROUND
  It is not clear how decreased activity quantitatively affects energy balance (EB) in subjects feeding ad libitum.
  
  
  OBJECTIVE
  We assessed the effect of an imposed sedentary routine on appetite, energy intake (EI), EB, and nutrient balance in lean men for 7 d.
  
  
  METHODS
  Six men with a mean (+/-SD) age of 23.0 +/- 2.3 y, weight of 69.2 +/- 11.4 kg, and height of 1.76 +/- 0.07 m were each studied twice during a sedentary [1.4 x resting metabolic rate (RMR)] and a moderately active (1.8 x RMR) regimen. During each treatment, they resided in the whole-body indirect calorimeter for the 7 d and had ad libitum access to a medium-fat diet of constant, measurable composition. Meal size, frequency, and composition were continually monitored. Motivation to eat was recorded during waking hours. Subjects were weighed in light clothing each morning, and their weight was corrected to nude.
  
  
  RESULTS
  Energy expenditure was 9.7 and 12.8 MJ/d [P < 0.01; SE of the difference between means (SED) = 0.41] during the sedentary and active regimens, respectively. EI was 13.5 and 14.4 MJ/d (P = 0.463, SED = 1.06), respectively. There was no regimen effect on hunger, appetite, or body weight. By day 7, cumulative EB was 26.3 and 11.1 MJ, respectively.
  
  
  CONCLUSIONS
  Reducing a level of physical activity from 1.8 to 1.4 x RMR can markedly affect EB. A sedentary routine does not induce a compensatory reduction of EI and leads to a significantly positive EB, most of which is stored as fat.
authors.affiliation: Biomathematics and Statistics Scotland, Aberdeen, United Kingdom. j.stubbs@rri.sari.ac.uk
authors.forename: R James
authors.initials: RJ
authors.lastname: Stubbs
authors.forename: Darren A
authors.initials: DA
authors.lastname: Hughes
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Johnstone
authors.forename: Graham W
authors.initials: GW
authors.lastname: Horgan
authors.forename: Neil
authors.initials: N
authors.lastname: King
authors.forename: John E
authors.initials: JE
authors.lastname: Blundell
mesh_terms: D000328:Adult; D001066:Appetite; D001481:Basal Metabolism; D002153:Calorimetry, Indirect; D004435:Eating; D004734:Energy Metabolism; D015444:Exercise; D006801:Humans; D008297:Male