CONSUMPTION OP FOOD IN THE HEALTHY 9 



intervals of intestinal inactivity, which occur from six to eight hours after 

 meals, the values for the intake of O2 and the excretion of CO^ per minute 

 are quite constant for any healthy individual, and in different healthy indi- 

 viduals they vary only within certain limits. In these " fasting values " we 

 have standards, variation from which in one or the other direction denotes 

 pathologic change. 



In conclusion, direct calorimetry must be considered as the exact method 

 by which to determine the entire transference of energy in the resting body. 

 This coincides, as already mentioned, with the total loss of heat, the coinci- 

 dence of which with the heat-equivalent of the food stuffs consumed have 

 been determined by Eubner in animals by masterly experiments. In man, 

 and especially in the sick, direct calorimetric estimations to determine the 

 quantity of the total metabolism have been carried out only in isolated cases 

 (see below). 



C. THE ENERGY REQUIREMENT OF THE HEALTHY 



The quantity of food required by a workman while performing " moderate " 

 labor Voit stated to be 118 grams of albumin, 50 grams of fat, and 500 grams 

 of carbohydrates. This was based upon many experiences taken from daily 

 life, and corresponds with the results of numerous exact analyses of metab- 

 olism carried out, according to the method described above, in Voit's labora- 

 tory (comparison of the intake and output). For a long time Voit's princi- 

 ples existed almost as a dogma. Later the total calory value to which this 

 diet corresponds (3,055 calories), as well as the large amount of albumin 

 contained in it, became the subject of lively discussion, in which the clinical 

 investigators took a prominent part. 



If the performance of muscular work increases the energy requirement 

 of the body above that of rest (and, in fact, it multiplies several times the 

 heat equivalent to the work done), the calory requirement of the "workman" 

 cannot be estimated otherwise than by considering the amount of work to 

 be performed. The rich statistical material which is now at hand confirms 

 the requirement of Voit for about 43 calories (which is the amount contained 

 in the above quantity of food per kilogram of body-weight) for persons doing 

 active muscular work. 



From many observations Rubner calculates as the medium amount for 

 a twenty-four-hour metabolism in the healthy adult, of average body size, 

 and weighing 70 kilograms : 



Pure Calory per 



calories. kilogram. 



At rest 2,303 = 82.9 



With slight muscular work 3,445 = 84.9 



With moderate muscular work 2,868 = 41.0 



With exhausting muscular work 8,362 = 48.0 



With a deduction of 8 per cent, from the 3,055 large calories which are 

 contained in Voit's amount of food, this corresponds exactly with Buhner's 

 calculations. 



