title: Anthropometric predictors of body fat in a large population of 9-year-old school-aged children.
abstract: To develop and cross-validate predictive models for percentage body fat (%BF) from anthropometric measurements [including BMIz-score (zBMI) and calf circumference (CC)] excluding skinfold thickness.
  
  
  
  A descriptive study was carried out in 3,084 pre-pubertal children. Regression models and neural network were developed with %BF measured by Bioelectrical Impedance Analysis (BIA) as the dependent variables and age, sex and anthropometric measurements as independent predictors.
  
  
  
  All %BF grade predictive models presented a good global accuracy (≥91.3%) for obesity discrimination. Both overfat/obese and obese prediction models presented respectively good sensitivity (78.6% and 71.0%), specificity (98.0% and 99.2%) and reliability for positive or negative test results (≥82% and ≥96%). For boys, the order of parameters, by relative weight in the predictive model, was zBMI, height, waist-circumference-to-height-ratio (WHtR) squared variable (_Q), age, weight, CC_Q and hip circumference (HC)_Q (adjustedr2= 0.847 and RMSE = 2.852); for girls it was zBMI, WHtR_Q, height, age, HC_Q and CC_Q (adjustedr2= 0.872 and RMSE = 2.171).
  
  
  
  %BF can be graded and predicted with relative accuracy from anthropometric measurements excluding skinfold thickness. Fitness and cross-validation results showed that our multivariable regression model performed better in this population than did some previously published models.
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal; Instituto Superior de Ciências da Saúde Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: Sílvia M
authors.initials: SM
authors.lastname: Almeida
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal; Instituto Superior de Ciências da Saúde Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: José M
authors.initials: JM
authors.lastname: Furtado
authors.affiliation: Instituto Superior de Ciências da Saúde Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Mascarenhas
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Ferraz
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal; Instituto Superior de Ciências da Saúde Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: Luís R
authors.initials: LR
authors.lastname: Silva
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal; Department of Obstetrics and Gynecology of University of Medicine of Warsaw Warsaw Poland.
authors.forename: José C
authors.initials: JC
authors.lastname: Ferreira
authors.affiliation: Clinical and Experimental Endocrinology Group, Unit for Multidisciplinary Research in Biomedicine UMIB, ICBAS University of Porto Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Monteiro
authors.affiliation: Instituto de Investigação e Inovação em Saúde, and IBMC - Instituto de Biologia Molecular e Celular Universidade do Porto Portugal; Instituto de Ciências Biomédicas de Abel Salazar Universidade do Porto Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Vilanova
authors.affiliation: Centro de Genética Médica e Nutrição Pediátrica Egas Moniz Campus Universitário Monte da Caparica Portugal; Instituto Superior de Ciências da Saúde Egas Moniz Campus Universitário Monte da Caparica Portugal.
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Ferraz
keywords: Anthropometry; body fat grade models; children; prediction equations