LLLI Center for Breastfeeding Information
Journal Abstract of the Month for September 2005
"Duration of Breastfeeding and Risk of Overweight: A Meta-Analysis"
Authors: Thomas Harder, Renate Bergmann, Gerd Kallischnigg, and Andreas Plagemann
Am J Epidemiol 2005: 162:397-403
In a previous meta-analysis, the authors were able to make a connection between breastfeeding and lowered risk for becoming overweight later in life. In this study, they attempted to assess whether the length of breastfeeding significantly impacts this lowered risk. In other words, they ask the question, "Does the breastfed child's risk of becoming overweight continue to decline proportionally the longer breastfeeding continues?"
Seventeen original studies published between 1966 and 2003 which compared breastfed with formula-fed infants and reported breastfeeding duration were included in the analysis. Statistical analysis revealed some startling and conclusive results. Beginning after the first month of breastfeeding and continuing through a plateau at 9 months of age, the risk of future overweight is reduced by 30 percent. Additional analysis further refined this information by concluding that for each month of breastfeeding, the risk of becoming overweight was reduced by 4 percent. It is not known how this mechanism works, although there is some speculation about the effects of neonatal nutrition on the developing areas of the brain that control appetite and body weight. It is also not clear whether this effect continues beyond the 9 th month of breastfeeding, although since most of the studies included infants who were only partially breastfed, it seems logical that exclusively-breastfed infants might derive an even greater benefit.
Variations in the definition of "overweight" between the original studies were found to have minimal impact on the conclusions reached. Age at follow-up was also found to be irrelevant. It is not clear from this analysis whether these results are valid across all racial/ethnic lines, as most of the studies did not include racial or ethnic information. Despite this, the answer to the question posed by the authors seems to be a resounding, "Yes!"
This paper is categorized by the following keywords:
Obesity/Weight Concerns (Baby)
Growth of the Breastfed Baby
An additional abstract of this article may be viewed at this link.
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LLLI provides additional information on weight gain issues in the breastfed baby. Go to these links for related articles and information from La Leche League International's publication for new mothers, NEW BEGINNINGS:
Additional Research Information from LLLI’s Center for Breastfeeding Information is available at this link: