15,341 adolescents ages 9-14 (children of Nurses' Health Study
II) and their parents were mailed and responded to separate questionnaires
addressing weight, height, infant feeding practices, diet, activity
level, mother's weight & height, Tanner stage, etc.1
Feeding practices divided into length of breastfeeding (0, <1
mo, 1-3 mo, 4-6 mo, 6-9 mo, >9 mo), and type of feeding (breast
Multivariate analysis was performed with breastmilk versus formula
and relationship to adolescent overweight. The results were adjusted
for sex, age, tanner stage, mother's BMI, energy intake, physical
activity, hours of TV watching, and birth weight.
In first six months of life, 62% of the subjects were mostly or
only fed breast milk, and 31% were mostly or only fed formula.
Odds Ratio (OR) for being overweight as an adolescent if fed only
or mostly breast milk for first 6 months was 0.78 (CI 0.66-0.91)
If mother's BMI < 25 vs > 30, OR = 0.27 for overweight child regardless
of breastfeeding status.