Trajectories of childhood weight gain: the relative importance of local environment versus individual social and early life factors.
OBJECTIVE
To determine the association between local environmental factors with child weight status in a longitudinal study, using a semi-parametric, group-based method, while also considering social and early life factors.


METHODS
Standardized, directly measured BMI from 4-10 y of age, and group-based trajectory modeling (PROC TRAJ) were used to estimate developmental trajectories of weight change in a Québec birth cohort (n = 1,566). Associations between the weight trajectories and living location, social cohesion, disorder, and material and social deprivation were estimated after controlling for social and early life factors.


RESULTS
FOUR WEIGHT TRAJECTORY GROUPS WERE ESTIMATED: low-increasing (9.7%); low-medium, accelerating (36.2%); medium-high, increasing (43.0%); and high-stable (11.1%). In the low-increasing and medium-high trajectory groups, living in a semi-urban area was inversely related to weight, while living in a rural area was positively related to weight in the high-stable group. Disorder was inversely related to weight in the low-increasing group only. Other important risk factors for high-stable weight included obesity status of the mother, smoking during pregnancy, and overeating behaviors.


CONCLUSIONS
In this study, associations between local environment factors and weight differed by trajectory group. Early life factors appear to play a more consistent role in weight status. Further work is needed to determine the influence of place on child weight.
Institute of Population Health, University of Ottawa, Ottawa, Ontario, Canada. carter.megan@gmail.com
Megan A
MA
Carter
Lise
L
Dubois
Mark S
MS
Tremblay
Monica
M
Taljaard
Bobby L
BL
Jones
D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005190:Family; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D011247:Pregnancy; D011792:Quebec / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking; D012924:Social Conditions; D012931:Social Environment; D012959:Socioeconomic Factors; D015430:Weight Gain