Energy Requirements during First Two Years of Life Based on Measurements of Energy Expenditure and Growth

Abstract 633 Poster Session II, Sunday, 5/2 (poster 153)

Current recommendations for energy intake of infants and children are based on observed energy intakes due to a lack of data on energy expenditure, the preferred basis for estimating energy requirements. The purpose of this study was to estimate energy requirements during the first two years of life from measurements of total energy expenditure (TEE) and energy deposited as fat and protein.

Methods: Measurements were performed on 76 healthy, term infants (40 breast-fed (BF) and 36 formula-fed (FF)) at 3, 6, 9, 12, 18, and 24 mo of age. TEE was measured by the doubly-labeled water (²H₂ ¹⁸O) method. Energy deposition was estimated from changes in body fat and protein. Fat was measured using a multicomponent model based on total body water by deuterium dilution; total body potassium (TBK) by whole body counting; and bone mineral content by dual energy x-ray absorptiometry. Protein was estimated from TBK. Energy equivalents for fat and protein deposition were taken as 38.7 kJ/g and 23.6 kJ/g, respectively. Data were analyzed by repeated measures ANOVA.

Results: (Table) Energy deposition differed by age (P=0.001). Adjusted for weight, TEE and energy requirements differed by feeding group (BF<FF) (P=0.002), but not by age or gender. Estimated energy requirements are 15-27% lower than current recommendations.

Table 1 No caption available.

Conclusion: The new data on TEE and energy deposition provide strong evidence that current recommendations for energy intake during the first two years of life should be revised.