Infant milk formulas are used in situations in which the milk of the mother or of other donors is not available. Some neonatal units use these formulas to improve the weight gain of very low birth weight newborns (9,10). The prevention of growth restriction of preterm newborns during hospitalization is of extreme importance since there is evidence suggesting that appropriate postnatal growth is associated with better neurological development and other benefits such as improved immune response and reduced risk of infections (11,12).