title: Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents.
abstract: To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents;
  
  
  
  The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO) were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of %FM;
  
  
  
  A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78-0.80). Differences occurred in both references (IOFT and WHO) in relation to the criteria (p < 0.001). Both references demonstrated a good ability to predict sensitivity (between 84% and 93%) and specificity (between 83% and 88%) in both sexes of children and adolescents;
  
  
  
  A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution.
authors.affiliation: Instituto de Actividad Física y Salud, Universidad Autonoma de Chile, 5 Poniente 1670, Talca, Chile. rossaunicamp@gmail.com.|Faculty of Physical Education, State University of Campinas, Avenida Érico Veríssimo, 701, Cidade Universitária Zeferino Vaz, Barão Geraldo, CEP 13083-851, Campinas, Brazil. rossaunicamp@gmail.com.|Department of Research, Universidad Científica del Sur, Panamericana Sur Km 19 Villa, Lima, Perú. rossaunicamp@gmail.com.
authors.forename: Rossana
authors.initials: R
authors.lastname: Gómez-Campos
authors.affiliation: Growth and Development Lab, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences, University of Campinas (UNICAMP), CEP 13083-887, Campinas-SP, Brazil. raqueldlanger@gmail.com.
authors.forename: Raquel
authors.initials: R
authors.lastname: David Langer
authors.affiliation: Growth and Development Lab, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences, University of Campinas (UNICAMP), CEP 13083-887, Campinas-SP, Brazil. roseanefguimaraes@gmail.com.
authors.forename: Roseane
authors.initials: R
authors.lastname: de Fátima Guimarães
authors.affiliation: Growth and Development Lab, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences, University of Campinas (UNICAMP), CEP 13083-887, Campinas-SP, Brazil. mari_martini08@yahoo.com.br.
authors.forename: Mariana
authors.initials: M
authors.lastname: Contiero San Martini
authors.affiliation: Faculty of Physical Education, State University of Campinas, Avenida Érico Veríssimo, 701, Cidade Universitária Zeferino Vaz, Barão Geraldo, CEP 13083-851, Campinas, Brazil. mcossio1972@hotmail.com.|Department of Physical Activity Sciences, Catholic University of Maule, Av. San Miguel 3605, Talca, Chile. mcossio1972@hotmail.com.|Research Network on Human Biological Development, Urb. Amauta C-6, Jose Luis Bustamante y Rivero, Arequipa, Peru. mcossio1972@hotmail.com.
authors.forename: Marco
authors.initials: M
authors.lastname: Cossio-Bolaños
authors.affiliation: Faculty of Physical Education, State University of Campinas, Avenida Érico Veríssimo, 701, Cidade Universitária Zeferino Vaz, Barão Geraldo, CEP 13083-851, Campinas, Brazil. miguelfef@hotmail.com.
authors.forename: Miguel
authors.initials: M
authors.lastname: de Arruda
authors.affiliation: Growth and Development Lab, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences, University of Campinas (UNICAMP), CEP 13083-887, Campinas-SP, Brazil. gilguer@fcm.unicamp.br.
authors.forename: Gil
authors.initials: G
authors.lastname: Guerra-Júnior
authors.affiliation: Growth and Development Lab, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences, University of Campinas (UNICAMP), CEP 13083-887, Campinas-SP, Brazil. emaildozeique@gmail.com.
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Moreira Gonçalves
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002677:Chile; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012015:Reference Standards; D015203:Reproducibility of Results; D012737:Sex Factors
keywords: Body Mass Index; Chile; DXA; cut-off points; obesity