Effect of varying protein intake on energy balance, protein balance and estimated weight gain composition in premature infants.

OBJECTIVE

We studied the effect of varying only protein intake on energy balance, protein balance and estimated weight gain composition in premature infants fed either a formula with a protein content of 2.0 g/100 ml (F2) or a protein content of 1.5 g/100 ml (F1.5).

DESIGN

Premature infants were randomly allocated to receive F1.5 or F2. Weight gain composition was estimated from protein and energy balances. Energy expenditure was measured with doubly labelled water.

PATIENTS

F1.5, n = 8; gestational age 32 +/- 3 weeks, birth weight 1716 +/- 560 g. F2, n = 8; gestational age 32 +/- 3 weeks, birth weight 1544 +/- 488 g.

RESULTS

Infants fed F2 showed a significantly higher protein accretion (P = 0.003) and weight gain (P = 0.011) when compared to the infants fed F1.5. There were no differences in the energy balance. The estimated weight gain composition was different between both groups.

CONCLUSION

The F2 fed infants had an estimated weight gain composition comparable to the reported intrauterine values, while the F1.5 fed infants showed a weight gain composition more comparable to the reported values of the full term infant. The impact of nutrient composition in premature infant formulas on body composition and growth is discussed.