title: Percent body fat prediction equations for 8- to 17-year-old American children.
abstract: BACKGROUND
  Percent body fat equations are usually developed in specific populations and have low generalizability.
  
  
  OBJECTIVE
  To use a nationally representative sample of the American youth population (8-17 years old) from the 1999-2004 National Health and Nutrition Examination Survey data to develop gender-specific percent body fat equations.
  
  
  METHODS
  Percent body fat equations were developed for girls and boys using information on weight, height, waist circumference, triceps skin-folds, age, race/ethnicity and menses status compared to dual-emission X-ray absorptiometry. Terms were selected using forward and backward selection in regression models in a 2/3 development sample and were cross-validated in the remaining sample. Final coefficients were estimated in the full sample.
  
  
  RESULTS
  Final equations included ten terms in girls and eight terms in boys including interactions with age and race/ethnicity. In the cross-validation sample, the adjusted R2 was 0.818 and the root mean squared error was 2.758 in girls. Comparable estimates in boys were 0.893 and 2.525. Systematic bias was not detected in the estimates by race/ethnicity or by body mass index categories.
  
  
  CONCLUSIONS
  Gender-specific percent body fat equations were developed in youth with a strong potential for generalizability and utilization by other investigators studying adiposity-related issues in youth.
authors.affiliation: Department of Nutrition, School of Public Health, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: J
authors.initials: J
authors.lastname: Stevens
authors.forename: J
authors.initials: J
authors.lastname: Cai
authors.forename: K P
authors.initials: KP
authors.lastname: Truesdale
authors.forename: L
authors.initials: L
authors.lastname: Cuttler
authors.forename: T N
authors.initials: TN
authors.lastname: Robinson
authors.forename: A L
authors.initials: AL
authors.lastname: Roberts
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000293:Adolescent; D001741:Black or African American; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight / Q000208:ethnology; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008598:Menstruation; D017058:Mexican Americans; D009749:Nutrition Surveys; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012737:Sex Factors; D012885:Skinfold Thickness; D014481:United States / Q000453:epidemiology; D055105:Waist Circumference; D044465:White People
keywords: Adolescents; NHANES; anthropometry; dual-emission X-ray absorptiometry