Upon transitioning to enteral nutrition, human milk is preferable to formula initially in VLBW newborns because it speeds up development of the intestinal barrier and thereby reduces risk of necrotizing enterocolitis, with an absolute risk reduction of 4%. Donor human milk and maternal expressed breast milk are both associated with this benefit. One drawback of human milk is the imprecision in its calorie content. The fat content in human milk varies greatly among women; therefore, the energy content of human milk cannot be known as precisely as formula. Each time human milk is transferred between containers, some of the fat content may stick to the container, decreasing the energy content. Minimizing transfers of human milk between containers decreases the amount of energy loss. Formula is associated with greater linear growth and weight gain than donor breast milk in LBW infants.