Postprandial metabolism in infants of low birth weight.

Postprandial metabolic rate (MR) was measured after a standard test meal in 15 preterm appropriately grown (AA) infants, 11 small-for-gestational age (SGA) infants, and five fullterm normal infants. Resting MR before the feed was highest in SGA infants (228 kJ/kg/d, s.d.20) and lowest in AGA infants (181 kJ/kg/d, s.d. 30). The normal infants were intermediate. Postprandial MR increased by 18 per cent in the AGA group, 11 per cent in the SGA group, 4 per cent in the normal infants and not at all in sham-fed infants. There was a significant correlation between weight gain and the magnitude of the increase in postprandial metabolism. 'Specific dynamic action' may therefore reflect synthetic processes in these infants.