Breastfeeding and obesity at 14 years: a cohort study.
OBJECTIVE
To determine the influence of breastfeeding on overweight and obesity in early adolescence.


METHODS
Data about breastfeeding duration, BMI of children at 14 years, and confounding variables, were collected from an ongoing longitudinal study of a birth cohort of 7776 children in Brisbane. Prevalence of overweight and obesity at 14 years was assessed according to duration of breastfeeding, with logistic regression being used to adjust for the influence of confounders.


RESULTS
Data were available for 3698 children, and those not included were significantly different in age, educational level, income, race, birthweight, and small-for-gestational-age status. Breastfeeding for longer than six months was protective of obesity (OR 0.6, 95% CI 0.4, 0.96) though not of overweight. When confounding variables were considered the effect size diminished and lost statistical significance OR 0.8 (95% CI 0.5, 1.3). Breastfeeding for less than 6 months had no effect on either obesity or overweight though a trend was found for increased prevalence of overweight at 14 years with shorter periods of breastfeeding.


CONCLUSIONS
This investigation contributes to the gathering body of evidence that breastfeeding for longer than 6 months has a modest protective effect against obesity in adolescence.
Shields
Linda
L
Faculty of Health and Social Care, University of Hull, Hull, UK. l.shields@hull.ac.uk
O'Callaghan
Michael
M
Williams
Gail M
GM
Najman
Jake M
JM
Bor
William
W
D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D001942:Breast Feeding / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008423:Maternal Age; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology*; D050177:Overweight; D015995:Prevalence; D044469:Racial Groups; D012044:Regression Analysis