Size of Formula Bottles Contributes to Greater Infant Weight Gain and Size at Age Six Months

Elk Grove Village, IL–(ENEWSPF)–June 9, 2016.  While it’s known that formula-fed infants are at a greater risk of obesity later in life, it wasn’t known if this was caused by the formula, the formula bottle or some other impact. A new study shows that using a large formula bottle in early infancy contributed to greater weight gain and weight-for-length size, indicating that formula bottle size alone may be a risk factor for obesity.

The study, “Bottle Size and Weight Gain in Formula-Fed Infants,” to be published in the July 2016 Pediatrics (published online June 7), assessed 298 infants who were exclusively bottle fed by the two-month pediatric visit and found that use of a larger bottle predicted .16 kg more weight gain and a larger weight-for-length size by the six-month appointment. This finding supports the hypothesis that the mode of feeding (the bottle) is a more important factor in obesity than milk type, which has also been indicated by research showing infants fed only human milk by bottle gain more weight than breastfed infants.

Researchers conclude that while these findings are important because it’s known that infants fed primarily formula are heavier in infancy and at greater risk of obesity as they grow, more research is needed to more completely understand the link between bottle feeding and obesity risk to help inform interventions.


The American Academy of Pediatrics is an organization of 64,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults. For more information, visit