American Journal of Clinical Nutrition, Vol 48, 951-955, Copyright © 1988 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Energy costs of fat and protein deposition in the human infant

SB Roberts and VR Young
School of Science, Massachusetts Institute of Technology, Cambridge 02139.

The energy costs of depositing fat and protein in the low-birth-weight infant were determined by multiple-regression analysis from published information on metabolizable-energy intake and fat and protein deposition in groups of subjects fed different dietary regimes. The total energy requirement for deposition was 1.17 kJ/kJ deposited for fat (ie, 1 kJ deposited and 0.17 kJ expended for deposition, and 2.38 kJ/kJ for protein. These values are similar to published determinations for animal species with simple stomachs. The metabolizable-energy requirement for weight gain during infancy was calculated (range, 12.2- 25.1 kJ/g, or 2.9-6.0 kcal/g; means, 18.7 kJ/g, or 4.5 kcal/g) from the energy costs of fat and protein deposition and published information on changes in body composition during the first year of life.