title: Obesity and bullying: different effects for boys and girls.
abstract: OBJECTIVE
  To investigate whether weight category (underweight, average weight, overweight, and obese) at age 7.5 predicts bullying involvement at 8.5 years. Models were tested separately for boys and girls to investigate gender differences in association patterns.
  
  
  METHODS
  Prospective cohort study in southwest England. Height and weight were measured in children at age 7.5 (n = 8210). BMI (kg/m2) was used to define underweight, average weight, overweight, and obese children, according to British age and gender specific growth reference data. Overt (n = 7083) and relational (n = 6932) bullying behaviour was assessed in children at age 8.5.
  
  
  RESULTS
  After adjustment for parental social class, compared to average weight boys, obese boys were 1.66 (95% CI 1.04 to 2.66) times more likely to be overt bullies and 1.54 (1.12 to 2.13) times more likely to be overt victims. Obese girls were 1.53 (1.09 to 2.15) times more likely to be overt victims compared to average weight girls.
  
  
  CONCLUSIONS
  Obesity is predictive of bullying involvement for both boys and girls. Preadolescent obese boys and girls are more likely to be victims of bullying because they deviate from appearance ideals. Other obese boys are likely to be bullies, presumably because of their physical dominance in the peer group.
authors.affiliation: Centre for Paediatric Epidemiology and Biostatistics, Institute of Child Health, London, UK. l.griffiths@ich.ucl.ac.uk
authors.forename: L J
authors.initials: LJ
authors.lastname: Griffiths
authors.forename: D
authors.initials: D
authors.lastname: Wolke
authors.forename: A S
authors.initials: AS
authors.lastname: Page
authors.forename: J P
authors.initials: JP
authors.lastname: Horwood
mesh_terms: D001835:Body Weight; D002648:Child; D019548:Crime Victims / Q000523:psychology; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000523:psychology*; D050177:Overweight; D010379:Peer Group; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012919:Social Behavior; D012923:Social Class