i Reprinted from THE JOURNAL or BIOLOGICAL CHEMISTRY, Vol. XLVI, No. 1, March, 1921 



THE VARIATION AND THE STATISTICAL CONSTANTS 

 OF BASAL METABOLISM IN MEN. 



BY J. ARTHUR HARRIS AND F. G. BENEDICT. 



(From the Nutrition Laboratory and the Station for Experimental Evolution, 

 the Carnegie Institution of Washington.) 



(Received for publication, January 6, 1921.) 

 I. INTRODUCTION. 



i Physiologists now generally accept the so called basal metabolism 

 pf the individual as a standard in all comparisons involving the 

 ijonsideration of energy transformation. Furthermore, the tech 

 nical conditions under which measurements of the basal metabol- 

 sm shall be made are now generally agreed upon. The opinion 

 lias even been widely maintained that heat production per square 

 fieter of body surface area is a constant. 



A detailed review and discussion of the literature and the results 

 f a biometric analysis of a series of basal metabolism data for 

 ,36 men and 103 women have been given elsewhere. 1 The results 

 &amp;gt;f this analysis show the following coefficients of variation for 

 ihe averages 2 of the daily basal metabolism constants for the indi- 

 idual subjects. 



Men. Women. 



Total calories per 24 hrs 12 . 54 11 . 50 



Calories per kg. per 24 hrs 9.36 14.14 



Calories per square meter per 24 hrs 8.05 9.17 



1 Harris, J. A., and Benedict, F. G., Carnegie Inst. of Washington, Pub. 

 V 9, 1919, 129-200. 



These are averages of daily means in all cases in which measurements 

 )uld be made on more than 1 day. For 35 subjects a single daily mean 

 ily was available. 



In practise the catabolism of a subject is almost invariably measured in 

 vo or more short periods on a given day in a respiration apparatus. Tech- 

 Rally these are generally designated as minimum periods, since the lowest 

 ilues are generally found in the absence of muscular activity. The term 



somewhat misleading when averages of two or more periods are taken, 



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THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. XLVI, NO. 1 



