title: Developmental pathways leading to obesity in childhood.
abstract: BACKGROUND
  Researchers have yet to provide a comprehensive explanation of the variability in the development of childhood obesity, owing in part to the dearth of longitudinal studies. Such an understanding would contribute to the improvement of approaches for the primary and secondary prevention of childhood obesity. This study identifies, in a representative sample of Canadian children, age-related patterns of overweight and obesity between toddlerhood and childhood.
  
  
  METHODS
  The data are from cycles 2 through 5 (1996/1997 to 2002/2003) of the National Longitudinal Survey of Children and Youth. The sample comprised children aged 24 to 35 months at baseline, who were followed biennially over six years. Group-based mixture modelling analyses (using SAS PROC TRAJ) were conducted to identify the sex-specific developmental trajectories of body mass index (BMI).
  
  
  RESULTS
  Group-based modelling identified four BMI trajectories for the girls (stable normal BMI, early declining BMI, late declining BMI, and an accelerating rise to obesity) and three for the boys (stable normal BMI, transient high BMI, and a J-curve rise to obesity).
  
  
  CONCLUSIONS
  Identifying distinct, sex-specific BMI trajectories is valuable in understanding pathways through which a child may develop obesity. These findings have implications for further research and practice, in particular, that no single approach can be used to prevent or reduce levels of obesity.
authors.affiliation: School of Nursing, University of British Columbia, Vancouver, British Columbia V2Y 1Y1. Samar.Hejazi@nursing.ubc.ca
authors.forename: Samar
authors.initials: S
authors.lastname: Hejazi
authors.forename: V Susan
authors.initials: VS
authors.lastname: Dahinten
authors.forename: Sheila K
authors.initials: SK
authors.lastname: Marshall
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Ratner
mesh_terms: D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*