title: The influence of socioeconomic status on the incidence and evolution of obesity during early adolescence.
abstract: OBJECTIVE
  To analyze the influence of socioeconomic status on the prevalence, evolution and incidence of obesity between the ages of 12 y and 15 y in Belgium.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  2607 children from five social groups.
  
  
  METHODS
  The body mass index (BMI) measured during two school medical examinations carried out at an interval of two years between the ages of 12 y and 15 y.
  
  
  RESULTS
  Between the ages of 12 y and 15 y the inverse relation between social status and the prevalence of obesity is accentuated in girls. The increasing divergence between social groups was a result both of the greater incidence of new cases of obesity and the reduced improvement rate in obesity already present in adolescents of lower social classes.
  
  
  CONCLUSIONS
  Social inequalities in obesity increase during early adolescence. Preventive measures, targeting children of low socioeconomic status, should be put in place at this stage of life.
authors.affiliation: Laboratory for Epidemiology and Social Medicine, School of Public Health, Free University of Brussels, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: De Spiegelaere
authors.forename: M
authors.initials: M
authors.lastname: Dramaix
authors.forename: P
authors.initials: P
authors.lastname: Hennart
mesh_terms: D000293:Adolescent; D001530:Belgium / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000208:ethnology; D015995:Prevalence; D012189:Retrospective Studies; D012923:Social Class