Is my exclusively breastfed baby gaining too much weight?

By Kelly Bonyata, BS, IBCLC

It is normal for breastfed babies to gain weight more rapidly than their formula-fed peers during the first 2-3 months and then taper off (particularly between 9 and 12 months). There is absolutely NO evidence that a large breastfed baby will become a large child or adult. In fact, there is good research to indicate that breastfed babies are less likely to be obese children or adults than babies who were formula-fed.

Babies who gain quickly during infancy often start to slim down once they become more mobile; ie. rolling, crawling, pulling up, walking, running, etc. Often toddlers are very picky eaters and/or become almost too “busy” to take the time to eat. The fat laid down in infancy ensures that there are ample stores to pull from during the active toddler years.

Keep in mind, too, that breastmilk is a perfect food. There are NO empty calories or fillers. The amount of fat or calories in breastmilk is not affected by mom’s dietary fat or sugar intake. However, mom can change the types of fat in her milk by altering the types of fat that she eats. (See Can you affect the amount of fat or calories in your milk? What we know from research.)

Do not try to limit your baby’s nursing by stretching out feedings, limiting time at the breast, using a pacifier to “hold baby off” until a specified time has passed, or offering water so that baby nurses less. It can be dangerous to limit your baby’s growth by limiting nursing, as your baby needs the nutrients and fat for proper growth and brain development. Only by continuing to feed your baby on cue will you ensure that his needs are perfectly met and that your milk supply is maintained.

A 2002 study (Stettler N, Zemel BS, Kumanyika S, Stallings VA. Infant Weight Gain and Childhood Overweight Status in a Multicenter, Cohort Study. Pediatrics 2002; 109: 194-199) received a lot of press coverage and worried some parents. The researchers concluded, “A pattern of rapid weight gain during the first 4 months of life was associated with an increased risk of overweight status at age 7 years, independent of birth weight and weight attained at age 1 year.” However, the study data included practically no information on how the infants were fed (including the length/exclusivity of breastfeeding and when solids were introduced). The study looked at data for over 19,000 children who were born between 1959 and 1965 in 12 U.S. cities. These children were born at around the height of formula feeding in the US, and also at a time when very early introduction of solids was recommended. Both formula feeding and early intro of solids have been shown to increase the chance of childhood obesity. Per La Leche League, Dr. Nicholas Stettler (who headed up this study) “said that there is an easy way to prevent this obesity; simply follow the American Academy of Pediatrics’ guideline — breastfeed the infant exclusively for six months, followed by the slow introduction of solids and continued breastfeeding to one year or beyond.”

What can cause faster weight gain than the norm in an exclusively breastfed baby?

  • Genetics. Did your older children gain quickly as infants? What about Mom & Dad – are you large in size, or were you large as babies? What about other family members?
  • Overabundant supply can result in more rapid than normal weight gain (over an ounce per day). However, oversupply is not a concern unless it is causing problems for mom or baby.
  • Rarely, too-rapid weight gain can be related to health problems, such as congestive heart failure, renal anomalies, and/or endocrine disorders. If baby has health problems, continued breastfeeding is even more important.


How I can help to prevent my child from becoming overweight?

  • The BEST thing you can do to lessen the chance that your baby will become overweight as a child or as an adult is to breastfeed as long as possible.
  • Avoid solids for at least 6 months (this is especially helpful for babies who come from a family with a history of obesity or allergies).
  • Once you start solid foods, add them slowly to baby’s diet. Nurse before offering solids, and make sure that the majority of baby’s calories come from breastmilk through the end of the first year.
  • Allow your child to eat to appetite – don’t push your child to continue eating when he is not hungry.
  • Once your baby becomes more active, allow him plenty of time to play and move around.
  • As your child becomes older, set a good example with healthy eating habits and exercise.

Additional Information

Is your baby nursing all the time? (this website)

Breast milk may help control growing appetite by Kim Severson, San Francisco Chronicle

Healthy weight for mom and baby through breastfeeding LLL Press Release, January 2002

Human Milk: The Best Gift for Future Heart Health LLL Press Release, January 2002, on weight gain during infancy, obesity and heart health

AAP Committee on Nutrition. Prevention of Pediatric Overweight and Obesity (Policy Statement). Pediatrics 2003 (August);112(2):424-430. (Reaffirmed 2/1/07)
In this policy statement, the AAP recommends that breastfeeding be encouraged, supported, and protected because the “Extent and duration of breastfeeding have been found to be inversely associated with risk of obesity in later childhood, possibly mediated by physiologic factors in human milk as well as by the feeding and parenting patterns associated with nursing.”

Strategies to Prevent Obesity in the United States from the US Centers for Disease Control and Prevention.
“Communities Should Increase Support for Breastfeeding”

Paul IM, Bartok CJ, Downs DS, Stifter CA, Ventura AK, Birch LL. Opportunities for the Primary Prevention of Obesity during Infancy. Adv Pediatr. 2009;56:107-33.

Owen CG, Martin RM, Whincup PH, Smith GD, Cook DG. Effect of infant feeding on the risk of obesity across the life course: a quantitative review of published evidence. Pediatrics, May 1, 2005; 115(5): 1367-77.
From the abstract: CONCLUSIONS: Initial breastfeeding protects against obesity in later life. However, a further review including large unpublished studies exploring the effect of confounding factors in more detail is needed.

Arenz S, Ruckerl R, Koletzko B, von Kries R. Breast-feeding and childhood obesity–a systematic review. Int J Obes Relat Metab Disord. 2004 Oct;28(10):1247-56.
From the abstract: Nine studies with more than 69,000 participants met the inclusion criteria. The meta-analysis showed that breast-feeding reduced the risk of obesity in childhood significantly…Breast-feeding seems to have a small but consistent protective effect against obesity in children.

Obesity from (General information)

Weight Issues in Children from the American Academy of Family Physicians (General information)

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