New insights into links between infant feeding and obesity

Jan 19 2009

The February edition of the Journal of Nutrition offers new insights into possible associations between infant feeding and health outcomes related to obesity.

According to David Barker, M.D., Ph.D., professor of clinical epidemiology at the University of Southampton, UK and professor of Cardiovascular in the Department of Medicine at the Oregon Health and Science University and one of the authors of the report, “A longer period of breastfeeding was associated with lower BMI (a measure for weight) at one year of age. This relationship disappeared by the age of 7 years.” Similarly, there was no significant difference in BMI at the age of 60 years associated with duration of breastfeeding.

These findings may help explain why some studies that examined breastfed infants during the first year of life suggested a protective effect of breastfeeding and obesity, whereas other studies that examined the relationship later in life have found no such effect.

The report features Dr. Barker and other nutrition experts who presented at the American Society for Nutrition's annual meeting last year. The session, Infant Feeding and the Development of Obesity: What Does the Science Tell Us?, brought together international experts in the field of infant nutrition to present their recent research that employed new methodology such as randomized clinical trials (involving breastfeeding promotion) as well as sibling pair analysis . Another session presenter, Michael Kramer, M.D., pediatrician and perinatal epidemiologist at McGill University, reported findings from his breastfeeding promotion intervention trial that support Dr. Barker's results. Dr. Kramer's research found that while breastfeeding promotion increased breastfeeding it did not reduce the development of obesity at 6.5 years of age..

Dr. Barker, whose study examined breastfeeding in a large group of sibling pairs that were followed into their late 60s, stated, “This type of study design controls for maternal factors. Differences in the long-term effects of breast and bottle feeding may reflect differences in the mothers rather than the effects of feeding itself.” Maternal factors include maternal health status, maternal care-giving, mother–child interactions or other health-related behaviors of the mother that may interfere with determining the association of infant feeding and health outcomes and the strength of any possible associations. Additionally, he added that his study augments the current literature on infant feeding, as “few studies have examined whether the duration of breastfeeding is associated with fatness in adult life.”

Other researchers featured in the report include Linda Adair, Ph.D., professor of nutrition at the University of North Carolina at Chapel Hill; Beth Mayer-Davis, Ph.D., R.D., professor of nutrition University of North Carolina at Chapel Hill; and Nancy Butte, Ph.D., professor of pediatrics at the Children's Nutrition Research Center at Baylor College of Medicine.

For the full supplement report, which will be released on January 16, please visit http://jn.nutrition.org/