title: Equations based on anthropometry to predict body fat measured by absorptiometry in schoolchildren and adolescents.
abstract: OBJECTIVE
  To develop and validate equations to estimate the percentage of body fat of children and adolescents from Mexico using anthropometric measurements.
  
  
  METHODS
  A cross-sectional study was carried out with 601 children and adolescents from Mexico aged 5-19 years. The participants were randomly divided into the following two groups: the development sample (n=398) and the validation sample (n=203). The validity of previously published equations (e.g., Slaughter) was also assessed. The percentage of body fat was estimated by dual-energy X-ray absorptiometry. The anthropometric measurements included height, sitting height, weight, waist and arm circumferences, skinfolds (triceps, biceps, subscapular, supra-iliac, and calf), and elbow and bitrochanteric breadth. Linear regression models were estimated with the percentage of body fat as the dependent variable and the anthropometric measurements as the independent variables.
  
  
  RESULTS
  Equations were created based on combinations of six to nine anthropometric variables and had coefficients of determination (r2) equal to or higher than 92.4% for boys and 85.8% for girls. In the validation sample, the developed equations had high r2values (≥85.6% in boys and ≥78.1% in girls) in all age groups, low standard errors (SE≤3.05% in boys and ≤3.52% in girls), and the intercepts were not different from the origin (p>0.050). Using the previously published equations, the coefficients of determination were lower, and/or the intercepts were different from the origin.
  
  
  CONCLUSIONS
  The equations developed in this study can be used to assess the percentage of body fat of Mexican schoolchildren and adolescents, as they demonstrate greater validity and lower error compared with previously published equations.
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico. Electronic address: lortiz@correo.xoc.uam.mx.
authors.forename: Luis
authors.initials: L
authors.lastname: Ortiz-Hernández
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico.
authors.forename: A Valeria
authors.initials: AV
authors.lastname: Vega López
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico.
authors.forename: Norma
authors.initials: N
authors.lastname: Ramos-Ibáñez
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico.
authors.forename: L Joana
authors.initials: LJ
authors.lastname: Cázares Lara
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico.
authors.forename: R Joab
authors.initials: RJ
authors.lastname: Medina Gómez
authors.affiliation: Universidad Autónoma Metropolitana (UAM), Departamento de Salud, Mexico City, Mexico.
authors.forename: Diana
authors.initials: D
authors.lastname: Pérez-Salgado
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000293:Adolescent; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008954:Models, Biological; D012885:Skinfold Thickness; D055815:Young Adult
keywords: Absorciometria de dupla energia de raios-X; Adolescentes; Adolescents; Anthropometry; Antropometria; Body fat; Children; Crianças; Dual X-ray absorptiometry; Gordura corporal; Mexico; México