576 



METABOLISM 



surface area in man this worker covered the body with thin underwear, 

 which was then impregnated with melted paraffin and reinforced with 

 paper strips to prevent it from changing in area when removed. This 

 model of the surface was afterwards cut up into flat pieces and photo- 

 graphed on paper of uniform thickness, the patterns being then cut out, 

 and weighed. From the results it was easy to calculate the actual sur- 

 face area. 



Where the height and weight are known, a fairly accurate computation 

 of the surface can be secured by using the following formulas : A=W- 425 

 XH- 725 X71.84; A being the surface area in square centimeters; H the 

 height in centimeters; and W, the weight in kilograms. Based on this 

 formula, a chart has been plotted from which the surface area may be de- 



WEIGHT-KILOGRAMS 



Fig. 175. Chart for determining surface area of man in square meters from weight in kilo- 

 grams (Wt.) and height in centimeters (Ht.) according to the formula: Area (Sq. Cm.) = Wt. 

 0.425 XHt. 0.725 X71.84. (From Dubois and Dubois, Arch. Int. Med., 1917, vol. 17.) 



termined at a glance (Fig. 175). Another method recently employed by 

 Benedict is based on measurements made from photographs of the subject 

 in various poses. 



By the use of these more accurate measurements of body surface, it is 

 now known that, although the surface-area law gives us constant results 

 for the energy output of different individuals of similar build, and offers 

 us a much more accurate basis than body weight for comparing those of dif- 

 ferent laboratory animals, yet it breaks down when applied to men in widely 

 differing states of body nutrition. Thus, in the case of a man who starved 

 for a month, the calorie output per square meter of surface decreased to- 

 wards the end of the fast by 28 per cent. Obviously, therefore, it would be 

 incorrect to draw conclusions regarding possible changes in energy output 



