BASAL METABOLISM. 



957 



from observations made upon a man who, while in the apparatus 

 did much muscular work on a bicycle ergometer: 



Income : Potential energy of material metabolized in body = 5459 CaL 



Outffo I ^'^^''gy given off from the body as heat 4833 Cal. 



^ \ Heat equivalent of muscular work 602 Cal. 



5435 Cal. 5435 CaL 



Experimental error 24 Cal, 



Basal Metabolism. — The actual results obtained from direct 

 calorimetric measurements corroborate those deduced from the 



r^ 



RESPIRATION CHAMBER 

 used 



%{]produced 



>» ^Ih'i 'ideficient\ 



^■^oit 



absorbed by absorbed by 



(A/a. OH \ . . /^^SO^ r 



_, f/VaOH ) , , 



] yca[0Hjj n 



ROTfiRY 



Fig. 301a. — Diagram of circulation of air through respiration apparatus. {Aiwater and Benedict.) 



study of the energy given off in the oxidation of the foodstuffs of 

 the daily diet. It is customary in these determinations to obtain 

 first what is known as the basal metabolism. By this term is 

 meant the heat production when the body is at rest and at a 

 sufficient time after a meal to escape the stimulating effect of 

 food. Observations show that in adults the basal metabolism in 

 round numbers is about 1600 calories a day for a man and 1300 

 to 1400 calories for a woman.* The difference between man and 

 woman is accounted for partly by differences in the average 

 weight or size, but it is stated that when this factor is allowed 

 for, the metabolism of a woman is somewhat lower than that of 

 a man of the same weight and age. Theoretically, a dietary 



* Harris and Benedict, "Publication 279, Carnegie Inst.," also "Scien- 

 tific Monthly," May, 1919. 



