Breastfeeding and overweight: longitudinal analysis in an Australian birth cohort.
OBJECTIVE
To examine adiposity in relation to breastfeeding using longitudinal analysis in an Australian birth cohort.


METHODS
Repeated surveys from 16 weeks gestation to 8 years in a cohort (N = 2087) recruited through antenatal clinics. Overweight was defined by National Center for Health Statistics 95th percentiles for weight-for-length at 1 year and body mass index (BMI) at 3, 6, and 8 years. Overweight was examined using Generalized Estimating Equations with results summarized as OR. BMI Z scores were analyzed in mixed models.


RESULTS
At 1 year, infants breastfed >12 months were the leanest group (mean Z score -0.16, 95% CL -0.28, -0.04; not breastfed 0.16, 95% CL 0.02, 0.29; breastfed < or = 4 months 0.31, 95% CL 0.22, 0.40; 5-8 months 0.17, 95% CL 0.06, 0.27; 9-12 months 0.11, 95% CL 0.01, 0.22). From 1 to 8 years, children breastfed < or = 4 months had the greatest risk of overweight (OR 1.29, 95% CL 0.89, 1.97) and the highest prevalence of maternal obesity, smoking, and lower education.


CONCLUSIONS
Infants breastfed >12 months were leaner at 1 year but not at 8 years. Breastfeeding < or = 4 months was associated with greatest risk of overweight and adverse maternal lifestyle. Familial factors may modify associations between breastfeeding and adiposity beyond infancy.
Burke
Valerie
V
University of Western Australia, School of Medicine and Pharmacology, Royal Perth Hospital, Perth, Australia. vburke@cyllene.uwa.edu.au
Beilin
Lawrie J
LJ
Simmer
Karen
K
Oddy
Wendy H
WH
Blake
Kevin V
KV
Doherty
Dorota
D
Kendall
Garth E
GE
Newnham
John P
JP
Landau
Louis I
LI
Stanley
Fiona J
FJ
D015992:Body Mass Index; D001835:Body Weight; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009035:Mothers; D009765:Obesity / Q000453:epidemiology* / Q000517:prevention & control; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014904:Western Australia / Q000453:epidemiology