title: Divergent body mass index trajectories between Aboriginal and non-Aboriginal Canadians 1994-2009--an exploration of age, period, and cohort effects.
abstract: OBJECTIVE
  Aboriginal Canadians have a high burden of obesity and obesity-related chronic conditions. Body mass index (BMI) trajectories from 1994 to 2009 were estimated for Aboriginal and non-Aboriginal Canadians using self-reported height and weight data from the National Population Health Survey to explore age, period, and cohort effects of BMI change.
  
  
  METHODS
  Linear growth curve models were estimated for 311 Aboriginal and 10,967 non-Aboriginal respondents divided into five birth cohorts born in the 1940s, 50s, 60s, 70s, and 80s.
  
  
  RESULTS
  Overall, Aboriginal Canadians experienced higher rates of BMI increase over the 14-year period. Rate of BMI increase was specifically higher for Aboriginal adults born in the 1960s and 1970s when compared with non-Aboriginal adults. At ages 25, 35, and 45, recent-born cohorts had consistently higher BMIs compared with earlier-born cohorts with magnitudes of differences typically larger in the Aboriginal population. Recent-born cohorts also exhibited steeper BMI trajectories.
  
  
  CONCLUSIONS
  Cohort effects may be responsible for the divergent BMI trajectories between Aboriginal and non-Aboriginal Canadians born in the 1960s and 1970s. Aboriginal Canadians, particularly of more recent-born cohorts, experienced faster increases in BMI from 1994 to 2009 than non-Aboriginal Canadians, suggesting that prevalence of obesity will continue to rise in this population without intervention.
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada. carmina.ng@utoronto.ca
authors.forename: Carmina
authors.initials: C
authors.lastname: Ng
authors.forename: Paul N
authors.initials: PN
authors.lastname: Corey
authors.forename: T Kue
authors.initials: TK
authors.lastname: Young
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D015988:Cohort Effect; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D009765:Obesity / Q000208:ethnology*; D044382:Population Groups; D015995:Prevalence