Method
Weight gain, breast milk
In this randomized controlled trial, 77 preterm infants (gestational age ≤33 weeks and birth weight <1500 g) who reached full enteral feeding with either fortified breast milk or preterm formula were included. They were randomized to receive either 4-<5 g/kg/day protein through extra protein supplementation (intervention) or 3-<4 g/kg/day protein. Weight gain, as well as length and head circumference growth, were monitored daily and weekly, respectively. Venous blood gas, blood urea nitrogen (BUN), and albumin levels were checked weekly.