The energy metabolism of infants in relation to age and nutritive condition

Abstract

Recent studies of the heat production of infants by Benedict and Talbot, 1 Bailey and Murlin 2 and Murlin and Hoobler 3 indicate a progressive increase from birth to the age of one year, whether the metabolism is reckoned on the basis of weight or on the basis of surface area (Meeh).

On the basis of weight the average metabolism of 13 newborn infants, determined while they were sleeping, is 1.87 calories per kilogram and hour; of normal infants between the ages of two and four months inclusive, it is 2.38 calories per kilogram and hour; between 6 and 12 months the average is 2,45 calories per kilogram and hour.

On the basis of a square meter of skin surface the metabolism of the newborns (up to 14 days of age) is, on the average, 25 calories per square meter and hour; of normal infants from two to four months inclusive, 35 calories per square meter and hour; and between six and twelve months the average is nearly 42 calories per square meter and hour. These differences on the basis of surface area are based on the assumption that the surface bears the same relation to weight () in all.

An analysis of all the observations on infants between the ages of two months and one year studied by Howland, 4 Benedict and Talbot and Murlin and Hoobler shows that the normal, recently-fed, sleeping infant produces about two and a half calories per kilogram and hour. With but two exceptions (out of 48) the underweight and atrophic infants produce more than this and the overweight infants produce less. It is suggested, therefore, that for practical purposes two and one half calories per kilogram and hour or sixty (in round numbers) calories per kilogram and twenty-four hours may be regarded as the average normal heat production of sleeping infants within this range.