Submitted to: Public Health Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2005
Publication Date: 10/16/2005
Citation: Butte, N.F. 2005. Energy requirements of infants. Public Health Nutrition. 8(7A):953-967. Interpretive Summary: The FAO/WHO/UNU recommendations for the energy intake of infants were revised based on newly available data using state of the art techniques. Energy requirements were derived from the sum of total energy expenditure (TEE) measured by doubly labeled water (DLW) method and energy deposition determined from body composition measurements. Total energy requirements naturally increase as the infants grow, and are higher in boys than girls due to differences in weight. In contrast to the 1985 FAO/WHO/UNU recommendations, energy requirements adjusted for body weight do not display a curvilinear pattern. Instead, energy requirements decrease from 473 kJ.kg-1.d-1 for boys and 447 kJ.kg-1.d-1 for girls at one mo of age to 337 kJ.kg-1.d-1 for boys and 341 kJ.kg-1.d-1 for girls at six mo, and thereafter tend to plateau. Energy deposition as a percentage of total energy requirement decreases from 40% at 1 mo to 3% at 12 mo of age. The 1985 FAO/WHO/UNU recommendations are 10–32% higher than the total energy requirements estimated herewithin and should be revised.
Technical Abstract: Objective: To estimate the energy requirements of infants from total energy expenditure and energy deposition during growth. Design: Energy requirements during infancy were estimated from total energy expenditure measured by the doubly labeled water method and energy deposition based on measured protein and fat gains. Setting: Database on the total energy expenditure and energy deposition of infants was compiled from available studies conducted in China, Chile, Gambia, Mexico, Netherlands, UK, and USA. Subjects: Healthy, term infants. Results: Total energy requirements (kJ day-1) increased with age and were higher in boys than girls due to differences in weight. Energy requirements decreased from 473 kJ.kg-1 per day for boys and 447 kJ.kg-1 per day for girls at 1 month of age to 337 kJ.kg-1 per day for boys and 341 kJ.kg-1 per day for girls at 6 months of age, and thereafter tended to plateau. Energy deposition as a percentage of total energy requirements decreased from 40% at 1 month to 3% at 12 months of age. These estimates are 10-32% lower than the 1985 FAO/WHO/UNU recommendations which were based on observed energy intakes of infants. Conclusions: Recommendations for the energy intake of infants should be revised based on new estimates of total energy expenditure and energy deposition.