title: Validation of the BOD POD with hydrostatic weighing: influence of body clothing.
abstract: OBJECTIVE
  Whole body air-displacement plethysmography (BOD POD), a new body composition technique, was validated against hydrodensitometry (UWW) in 67 women wearing a one-piece swimsuit (OP) who represent a wide range of body fatness and age. Additionally, the effect of trapped isothermic air in clothing while in the BOD POD was examined by comparing different clothing schemes (a one-piece swimsuit (OP), two-piece swimsuit (TP), a hospital gown (HG), and a hospital gown previously included in a volume calibration (GC)) in a subset of 25 women.
  
  
  METHODS
  Cross-sectional data analysis.
  
  
  METHODS
  67 healthy Caucasian females.
  
  
  METHODS
  Body density g/cm3 (Db) by BOD POD and UWW.
  
  
  RESULTS
  In 67 females UWW Db (1.030+/-0.020 g/cm3) was higher (P<0.01) than BOD POD Db (1. 028+/-0.020 g/cm3). This is a difference of 1.0% fat. The R2 was 0. 94, SEE was 0.005 g/cm3 and the regression between Db by UWW and BOD POB did not significantly deviate from the line of identity. In the subset group of 25 subjects, OP Db (1.040+/-0.014 g/cm3) and TP Db (1.040+/-0.014 g/cm3) were significantly lower (P<0.01) than UWW Db (1.044+/-0.014 g/cm3) or a difference of 1.9% fat. The R2 was 0.86 and the SEE was 0.005 g/cm3 and the regression between Db by UWW and both OP and TP did not significantly deviate from the line of identity. HG Db (1.056+/-0.016 g/cm3) and GC Db (1.037+/-0.016 g/cm3) were significantly different (P<0.01) from UWW Db (1.044+/-0. 014 g/cm3). This difference in density translates to a difference of 5.5% and 3.2% fat respectively. The regression between Db by UWW and both HG and GC significantly deviated from the line of identity.
  
  
  CONCLUSIONS
  This study supports the use of the BOD POD as a substitute for UWW. However, caution should be made in using the BOD POD if subjects are clothed in anything other than a tight fitting swimsuit.
authors.affiliation: Division of Physiology and Metabolism, Departments of Nutrition Sciences and Human Studies, University of Alabama at Birmingham, Birmingham, AL 35294-1250, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Fields
authors.forename: G R
authors.initials: GR
authors.lastname: Hunter
authors.forename: M I
authors.initials: MI
authors.lastname: Goran
mesh_terms: D000293:Adolescent; D000328:Adult; D000388:Air; D001823:Body Composition; D003020:Clothing; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D010993:Plethysmography, Whole Body / Q000592:standards*; D012044:Regression Analysis; D015203:Reproducibility of Results