Total energy expenditure in small for gestational age infants.

Abstract

OBJECTIVE: To measure total energy expenditure and body composition in small for gestational age (SGA) infants, to investigate hypermetabolism. METHODS: A cross-sectional study was performed in 52 small for gestational age (SGA) measured at 5 weeks of age, using existing data from appropriate for gestational age (AGA) infants as controls. The doubly-labelled water technique was used to assess both total energy expenditure and body composition in both cohorts of infants. RESULTS: Multiple regression analysis revealed that expressing energy expenditure per kg fat free mass adjusts for body composition in infants of this age. Regression analysis also showed that the relation between total energy expenditure and fat free mass differed between the two groups. CONCLUSION: These data indicate that for a given fat free mass, the total energy expenditure of SGA infants is greater than that of AGA infants. Such data should be taken into account when energy requirements for SGA infants are being considered.