Could your choice of baby formula start your baby off on a path towards obesity?  It's possible.  

A study published recently in the journal Pediatrics found that babies who were fed a particular type of infant formula gained more weight than other babies and continued to gain weight faster throughout their first year of life.

Researchers from the Monell Chemical Senses Center in Philadelphia wondered studied how different types of infant formulas would affect developing babies.  They compared formulas based on cow’s milk (whose proteins are intact) with those made with proteins that are pre-digested.  These formulas, known as protein hydrolysate formulas (or PHFs), have more free amino acids and about 35% more protein than cow’s-milk formulas.  They are often marketed as "allergy" formulas for babies who cannot tolerate or are allergic to the whole proteins.

For their study, the researchers recruited 56 mothers who had already chosen to formula feed their babies.  Roughly half of the babies were randomly assigned to get cow’s-milk formula, while the other half got the PHF formula. The mothers, who were of similar age, race, ethnicity, BMI and income, did not know which type of formula their infants received. Babies in both groups had similar birth weights and lengths.

Researchers noted a difference in the development of the two groups of babies within the first few months.  Within six weeks, the babies receiving cow’s-milk formula had significantly higher weight-per-length than the babies on PHF formula. By 3.5 months, the cow’s-milk formula babies also had significantly higher weight-per-age than the PHF babies.  Interestingly, the PHF babies weight (per length and per age) matched those of breast-fed babies.

So, babies are supposed to gain weight, right?  But the babies in this study who were fed cow milk formula were gaining more weight, and gaining it faster than might be considered healthy.  Most troubling, the babies who received cow's milk formula continued to gain excessive weight throughout the course of the study, even when both groups started eating solid foods.

Is cow milk formula making babies fat?  Maybe.  Talk to your health care provider if you're concerned about the formula your baby is eating. 

Does formula make babies fat?
New study finds that certain types of infant formula stimulate more weight gain in babies than others.