The Pathology of Metabolism in 

 Infancy and Early Childhood 



W. McKIM MARRIOTT 



ST. LOUIS 



The metabolic processes of the young are essentially the same in char- 

 acter as those of the adult but are relatively much more active. In the 

 case of infants and young children a large intake of food per unit of 

 body weight is necessary not only to supply material for growth but also 

 to allow for a very active energy exchange. Thus an average breast fed 

 infant ordinarily takes in food having a fuel value of approximately 100 

 calories per kilogram of body weight per day or about three times as 

 much per unit of weight as an adult doing a moderate amount of work. 

 Approximately 15 per cent of the food taken in under normal conditions 

 is used for growth. This latter figure is based on the known average gain 

 in weight and the caloric value of the solid material which comprises the 

 new tissue formed. 



On account of the very active metabolism during infancy, all of the 

 organs of the body concerned with the utilization of food are constantly 

 working at much nearer their limits of capacity than in the case of older 

 individuals. The margin of safety is small and when any of the organs 

 are overtaxed by excessive demands made upon them or when their func- 

 tional capacity is decreased, even though only temporarily, as the result 

 of infection or other influences, the course of metabolism may be pro- 

 foundly altered. 



Fortunately the young organism recovers relatively rapidly from the 

 results of disordered metabolism and permanent damage is not so likely 

 to occur as in the case of the adult. The overtaxing of an individual 

 organ is not so serious when processes of growth and repair are active. 

 Thus the capacity of the pancreas is often overtaxed in infancy, transitory 

 glycosuria is frequent and there may be evidences of an insufficient forma- 

 tion of the "external" secretion, but as the pancreas ordinarily doubles in 

 size during the first four months of life, complete recovery of function 

 is usual. The same may be said of other organs concerned with the metab- 

 olism. 



The high basal metabolism of the young individual results in the rapid 



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