title: The problem of obesity among adolescents in Hong Kong: a comparison using various diagnostic criteria.
abstract: BACKGROUND
  Obesity is now a global epidemic. In this study, we aimed to assess the rates of obesity using several major diagnostic criteria in Chinese school adolescents in Hong Kong.
  
  
  METHODS
  This is a cross-sectional study. Using a computer-generated coding system, we randomly selected schools from different geographical regions in Hong Kong to obtain a representative sample. Subjects aged 11-18 years of age were randomly selected from different class of the schools. Their rates of obesity according to four different international and local criteria were compared [International Obesity Task Force (IOTF) 2000 criterion; the Group of China Obesity Task Force (COTF) 2004 criterion; Centers for Disease Control and Prevention (CDC) 2000 Growth Charts and the Hong Kong Growth Survey (HKGS) charts in 1993].
  
  
  RESULTS
  Of the 2098 adolescents [982 (46.8%) boys and 1116 (53.2%) girls], the mean age (+/- SD) was 15.1 +/- 1.8 years (range: 11-18 years; median: 15.0 years). The crude rates of obesity were similar based on IOTF, COTF or CDC criteria (boys: 3.9-6.0%, girls: 1.8-3.7%), however, the rate increased to 11-27% if the HKGS charts were used. Obesity rate varied markedly according to age. It decreased from 8-10% among those aged 12-13 years to 2-4% among those aged 17-18 years.
  
  
  CONCLUSIONS
  The prevalence of obesity in Hong Kong adolescents using various diagnostic criteria were similar except for the 1993 HKGS criteria, which gave an exceeding high figure. Using the IOTF, COTF or CDC criteria, the adolescent obesity in Hong Kong varied from 1.8% to 6.0%.
authors.affiliation: The Hong Kong Institute of Diabetes and Obesity, Hong Kong SAR, China. garyko@cuhk.edu.hk
authors.forename: Gary T C
authors.initials: GT
authors.lastname: Ko
authors.forename: Risa
authors.initials: R
authors.lastname: Ozaki
authors.forename: Gary W K
authors.initials: GW
authors.lastname: Wong
authors.forename: Alice P S
authors.initials: AP
authors.lastname: Kong
authors.forename: Wing-Yee
authors.initials: WY
authors.lastname: So
authors.forename: Peter C Y
authors.initials: PC
authors.lastname: Tong
authors.forename: Michael H M
authors.initials: MH
authors.lastname: Chan
authors.forename: Chung-Shun
authors.initials: CS
authors.lastname: Ho
authors.forename: Christopher W K
authors.initials: CW
authors.lastname: Lam
authors.forename: Juliana C N
authors.initials: JC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D050177:Overweight / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012737:Sex Factors