The purpose of the study was to determine the factor associated with in-hospital weight loss of healthy, full-term newborns, including birth and infant-feeding factors as well as maternal and newborn demographics.
The study found a substantial difference in weight loss between exclusively breastfed and completely formula-fed newborns, which lost less. That disparity led the researchers to conjecture that formula-fed infants may be at risk of early overfeeding. Supplemented breastfed infants had similar weight loss patterns to the exclusively breastfed newborns.
"Degree of weight loss is critical in the decision to supplement breastfed infants with formula," said the study's authors, Patricia J. Martens, IBCLC, PhD, and Linda Romphf, IBCLC.
"However, given the overhydration of newborns, the early loss of meconium, and small fluid intake in the first few days, loss of 5-7 percent of birth weight is considered physiologically appropriate," Romphf added.
Newborn feeding experiences may be critical in metabolic imprinting and may factor into adult weight.
"The most influential predictor of weight loss in newborns is the type of infant feeding. Further study is critical, especially in light of current research on the association between early weight gain of formula-fed infants and adult obesity. Breastfeeding-supportive environments are necessary to support and enable women to breastfeed." The authors concluded.
The study is published in the Journal of Human Lactation.