67(3 



PHYSIOLOGY 



The same thing applies to man. If we desire to determine the basal 

 metabolism of any given individual we must find out his surface. If we 

 know the height and weight, the surface can be calculated by the following 

 formula (Du Bois) : 



S = -007184 x W' 425 x H 0>725 



where S is the surface in square metres, 

 W the weight in kilograms, 

 H the height in centimetres. 



In adult man the basal metabolism according to Du Bois is about 40 

 Calories per square metre per hour. The basal metabolism however is 

 not the same in the same individual under all kinds of conditions, but 

 depends on the state of nutrition of the animal. Thus in fattening an animal 

 the basal metabolism increases steadily as the animal gets fatter. It 

 requires much more food to keep a fat animal fat than to maintain it before 

 fattening in its original condition. The figure 40 Calories per square metre 

 per body surface applies to a well-nourished individual. If the food normally 

 supplied to the individual be diminished, he can go on working as before, 

 obtaining his energy at the expense of the fat and muscular tissues of his 

 own body. But when under this regime the weight has fallen about 12 per 

 cent, it is found that the basal metabolism i. e. the requirements of the 

 individual merely to keep himself alive is also largely reduced. Thus 

 in a squad of men investigated by Benedict, the food normally taken ranged 

 from 3200 to 3600 Calories per day. After these men had by restriction of 

 diet suffered a loss of 12 per cent, in their body weight, they were able to 

 maintain themselves^ at this reduced weight and to carry out the same 

 work as before on a diet of 2300 Calories. In one case where a man 5 ft. 

 2 in. had on a restricted diet been reduced in weight from 115 Ib. to 84 lb., 

 his basal metabolism was found to be diminished from 40-5 to 33 Calories 

 per square metre of body surface per hour. 



