NORMAL PROCESSES OF ENERGY METABOLISM 645 



child four weeks of age. In one period of four days when the food con- 

 tained 127 calories from protein, 105 from fat, and 168 from carbohy- 

 drate, or 400 calories in all, the average daily metabolism was 521 cal- 

 ories or 1337 calories per square meter of body surface (Meeh). In the 

 following period of five days the food contained 145 calories from pro- 

 tein, 368 from fat and 177 from carbohydrate or 629 calories in all. The 

 heat production averaged 569 calories per day or 1443 calories per square 

 meter. An increase of 70 per cent in the energy intake (largely fat) in- 

 creased the metabolism 10 per cent. Niemann observed a similar effect of 

 increasing the fat in 

 the food of an atrophic 

 infant 22 weeks old. 

 H e 1 1 e s o n(6) deter- 

 mined the resting me- 

 tabolism of a normal 

 infant five months old 

 and found that when 

 a part of the carbo- 

 hydrate of the diet 

 was replaced by an 

 isodynamic amount of 

 fat the heat produc- 

 tion was increased 8.3 

 per cent. Schloss- 

 mann made a similar 

 substitution in kind 

 though not in amount 

 and observed an in- 

 crease in the metab- 

 olism of fifteen per 

 cent. 



The writer is not 



of 



any 



aware 



ment establishing 



experi- 



the dynamic action of carbohydrate in infants. 

 The evidence of dynamic action thus far applies only to surplus food. 

 There is no satisfactory evidence that an ordinary feeding given at the 

 time when the infant is naturally ready for it raises the metabolism at 

 all. In the first place the difficulty of securing perfect repose when the 

 infant is hungry has thus far foiled all efforts to get a clean-cut contrast 

 before and after an ordinary feeding. Although Schlossman states in one 

 place that the effect of a meal may be discerned as long as 18 hours after- 

 ward, yet as already noted (page 642) neither Schlossman and Mur- 

 schauser nor Rubner and Heubner nor Rowland were able to demonstrate 

 a lower metabolism in fasting. Benedict and Talbot likewise assert that 



