[Protein quality and quantity in infant formulas. A critical look]

The ideal quantity and quality of dietary proteins in milk formulas employed for infant nutrition is still a matter of controversy and debate. During the last years, there has been a tendency to lower the protein content in response to new estimations of protein requirements based on protein intakes and growth rates of breastfed infants. In most infant formulas the protein content is in the range of 1.4-1.8 g/100 ml. The lower limit of this range appears to be adequate for the growth and metabolic needs of the healthy infant. The safety of a further reduction of this limit to 1.2 g/100 ml (~1.8 g/100 kcal), which has been recently proposed, needs additional scrutiny and observation. In addition, the real benefits of this choice have still to be proven. Adjustments for protein digestibility and quality have recently been introduced. The removal from the whey protein fraction of the glycomacropeptide (GMP), with a consequent reduction of excessive threonine intakes, is a novel approach and a further step in the development of infant formulas closer to the model of hu-man milk.