title: The association between objectively measured sitting and standing with body composition: a pilot study using MRI.
abstract: OBJECTIVE
  To investigate the association between objectively measured sitting and standing, using a postural allocation technique, with MRI-assessed body composition.
  
  
  METHODS
  The present study was a cross-sectional pilot study.
  
  
  METHODS
  Participants were examined at one centre located in London, UK.
  
  
  METHODS
  Normal weight Caucasian women (30.9±6.1 years; body mass index (BMI), 22.9±3.4 kg/m(2)) with desk-bound occupations were recruited to minimise variability in body composition outcomes. A convenience sample of 12 women was recruited in January 2014 from University College London.
  
  
  METHODS
  For each participant a number of body composition variables were attained from a single whole-body MRI session. Main outcome variables included: total and liver adiposity, visceral/subcutaneous fat ratio and BMI. Main exposure variables included: average sitting time, standing:sitting ratio and step count. Pearson correlations were carried out to examine associations between different activity categories and body composition variables.
  
  
  RESULTS
  There were significant correlations between average daily sitting and liver adiposity and visceral/subcutaneous abdominal fat ratio (r=0.66 and 0.64, respectively); standing:sitting ratio was moderately correlated with liver adiposity and visceral/subcutaneous abdominal fat ratio (r=-0.53 and -0.45); average daily step count was moderately correlated with liver adiposity, total adiposity and visceral/subcutaneous abdominal fat ratio (r=-0.45, -0.46 and -0.51, respectively).
  
  
  CONCLUSIONS
  This pilot study has provided preliminary evidence of relationships between objectively measured sitting and standing and precise measures of body composition.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Smith
authors.affiliation: Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: E L
authors.initials: EL
authors.lastname: Thomas
authors.affiliation: Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Bell
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Hamer
mesh_terms: D050154:Adiposity; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010865:Pilot Projects; D011187:Posture; D055815:Young Adult
keywords: Preventive Medicine; Public Health