Protein content decreases over time of lactation and is likely to be much lower in donor human milk than milk from mothers delivering prematurely. Current NICU practices are often based on the clearly misleading assumption that human milk has approximately 0.67 kcal/ml with stable protein content. “Assumed” protein intake from standard fortification is significantly lower than actual protein intake. These observations have led to clinical trials of “individualized” fortification, that is, adjusting the amount of added protein based on actual measurements of milk samples or based on metabolic parameters indicative of protein accretion in the neonate (e.g. blood urea nitrogen). Both methods led to increased protein intake and improved growth. A recent trial of a human milk fortifier with higher protein content demonstrated increased growth and fewer infants with weight below the 10th per centile