title: Socioeconomic position and risk of short-term weight gain: prospective study of 14,619 middle-aged men and women.
abstract: BACKGROUND
  The association between socioeconomic position in middle age and risk of subsequent, short-term weight gain is unknown. We therefore assessed this association in a prospective population based cohort study in Norfolk, UK.
  
  
  METHODS
  We analysed data on 14,619 middle-aged men and women (aged between 40-75 at baseline) with repeated objective measures of weight and height at baseline (1993-1997) and follow up (1998-2000).
  
  
  RESULTS
  During follow up 5,064 people gained more than 2.5 kg. Compared with the highest social class, individuals in the lowest social class had around a 30% greater risk of gaining more than 2.5 kg (OR 1.29; 95% CI 1.11-1.51; p for trend = 0.002). This association remained statistically significant following adjustment for sex, age, baseline BMI, smoking, and follow up time (OR 1.25; CI 1.07-1.46; p for trend <0.001). We also found no material difference between unadjusted models and those including all confounders and potential mediators.
  
  
  CONCLUSIONS
  Individuals of low socioeconomic position are at greatest risk of gaining weight during middle age, which is not explained by classical correlates of socioeconomic position and risk factors for obesity.
authors.affiliation: MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, UK. l.purslow@ucl.ac.uk
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Purslow
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Young
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: Nita
authors.initials: N
authors.lastname: Forouhi
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Brunner
authors.forename: Robert N
authors.initials: RN
authors.lastname: Luben
authors.forename: Ailsa A
authors.initials: AA
authors.lastname: Welch
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Shelia A
authors.initials: SA
authors.lastname: Bingham
authors.forename: Manjinder S
authors.initials: MS
authors.lastname: Sandhu
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D004032:Diet; D015444:Exercise; D005260:Female; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D006113:United Kingdom; D015430:Weight Gain