title: Epidemiology of childhood obesity--methodological aspects and guidelines: what is new?
abstract: BACKGROUND
  It is still a matter of debate as to how to define obesity in young people, although a growing consensus is to use body mass index (BMI) cutoffs to classify obesity in children and adolescents.
  
  
  OBJECTIVE
  This article provides a brief overview of issues related to the assessment of obesity in children and adolescents.
  
  
  RESULTS
  At present, BMI is probably the best choice among available measures. BMI can be easily assessed at low cost, and has a strong association with body fatness and health risks. However, as an indirect measure of adipose tissue, BMI has a number of limitations. Cole et al published a set of sex- and age-specific BMI cutoffs, which had been developed based on data collected in six countries, and the reference has been recommended for international use. Recently, several researchers have raised concerns regarding this international reference. It has been argued that population-specific standards should be used due to biological differences between populations.
  
  
  CONCLUSIONS
  BMI is a valid and feasible indirect measure of body fatness, but it suffers from a number of limitations. More efforts are needed to develop valid classifications of childhood obesity.
authors.affiliation: Department of Human Nutrition, Division of Epidemiology and Biostatistics, University of Illinois, Chicago, IL 60612, USA. youfwang@uic.edu
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D015992:Body Mass Index; D002648:Child; D004812:Epidemiologic Methods; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D011627:Puberty / Q000502:physiology; D012016:Reference Values; D012923:Social Class