Energy requirements of infants.

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 labelled 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, The 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.