Obesity Prevention Not Among Benefits of Being Breast-Fed

Both the CDC and the USDA have promoted breast-feeding to reduce the risk for childhood obesity, but whether this reduction in risk extends into adulthood has been unclear. In a prospective cohort study of participants in the Nurses’ Health Study II (NHS II) who were followed from 1989 to 2001, researchers assessed questionnaire responses from 35,500 predominantly white female registered nurses as well as from their biological mothers to examine the link between infant feeding history and adult BMI. At baseline, nurses self-reported their height, current weight, and weight at age 18; current weights were updated through biennial questionnaires and were validated with home visits to a subset of the population. Women were also asked to recall their body shapes at ages 5 and 10 using a nine-figure drawing. Participants’ mothers reported feeding methods, including whether and how long they had breast-fed their daughters. Exclusive breast-feeding was defined as not using formula, evaporated milk, or solid food supplements.

Overall, 41% of the women had been breast-fed; 59% were breast-fed for less than 1 week or not at all. In age- and covariate-adjusted analyses, being ever or exclusively breast-fed in infancy (regardless of duration) did not correlate significantly with BMI at age 18 or at adulthood, nor did it correlate with body shape at age 10. Women who were breast-fed for more than 6 months were slightly less likely to self-report a larger body shape at age 5.