title: Validation of simple epidemiological or clinical methods for the measurement of body composition in young children.
abstract: OBJECTIVE
  The present study aimed to determine the validity of simple epidemiological and clinical methods for the assessment of body fatness in preschool children.
  
  
  METHODS
  In 89 children (42 boys, 47 girls; mean age 4.1 SD 1.3y) measures of body fatness were made using total body water (TBW), dual energy x-ray absorptiometry (DXA), air displacement plethysmography (BODPOD) and skinfold thickness. Methods were compared by Bland-Altman analysis using TBW as the reference method, and by paired comparisons and rank order correlations.
  
  
  RESULTS
  Bias for DXA was +1.8% body fat percentage units (limits of agreement +15.5% to -11.9%), bias for BODPOD was -3.5% (limits of agreement +18.9% to -5.9%) and bias for skinfolds using the Slaughter equations was -6.5% (limits of agreement +10.0% to -23.1%). Significant rank order correlations with TBW measures of fatness were obtained for DXA estimates of fatness (r=0.54, P=0.01), but not for estimates of fat by skinfold thickness (r=0.20, P=0.2) or BODPOD (r=0.25, P=0.1). Differences between both DXA and BODPOD and the reference TBW estimates of body fatness were not significant (P=0.06 and P=0.1 respectively); however, the difference in estimated body fatness between skinfold thickness and TBW was significant (P<0.001).
  
  
  CONCLUSIONS
  Estimates of body fatness in preschool children were inaccurate at the level of the individual child using all the methods, but DXA might provide unbiased estimates and a means of making relative assessments of body fatness.
authors.affiliation: Public Health Nutrition Research Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, UK.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Jackson
authors.affiliation: University of Glasgow Medical Faculty, Division of Developmental Medicine, Yorkhill Hospitals, Glasgow, Scotland.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Donaghy
authors.affiliation: Clinical Nutrition Department, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kurosh
authors.initials: K
authors.lastname: Djafarian
authors.affiliation: University of Glasgow Medical Faculty, Division of Developmental Medicine, Yorkhill Hospitals, Glasgow, Scotland.
authors.forename: John J
authors.initials: JJ
authors.lastname: Reilly
keywords: BODPOD; Body Composition; Body Fatness; DXA; Preschoolers; Skinfold Thickness; TBW