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

Abstract

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.