CHAPTER XXXVIII 

 METABOLISM DURING STARVATION 



STARVATION may be brought about by withholding all food- 

 stuffs from the body, or by withholding separately either proteins, 

 water, or mineral salts. When all foodstuffs are withheld from an 

 animal, and only water given, the body begins to live at its own 

 expense, loss of weight ensues, and finally the animal dies. The time 

 of death depends largely upon the state of nutrition at the start. 

 The process of starvation is only painful in the last stages. Profes- 

 sional f asters appear in public from time to time, going without food 

 for as long as forty days, with apparently but little inconvenience to 

 themselves. From observations upon such, it appear:; that the ratio 

 of metabolism to actual body weight alters but little during starva- 

 tion; in other words, the Joss of weight and the lessening of the meta- 

 bolic processes of the body proceed together. At the beginning of 

 the starvation period, the nitrogen elimination in the urine quickly 

 drops to a fairly constant level. The drop is quicker the greater the 

 amount of nitrogen in the food eaten beforehand. For example, a 

 dog receiving 2,500 grammes of meat daily excreted on the first day 

 of starvation 60-1 grammes of urea; on the fifth day, 12-3 grammes. 

 With a moderate nitrogenous diet 1,500 grammes of meat the 

 excretion on these days was 26-5 and 14-8 grammes; with a diet poor 

 in nitrogen, 13-8 and 12-1 grammes. 



Day of Much N Moderate N Little N 



Starvation. in Food. in Food. in Food. 



1 GO-1 26-5 13-8 



2 24-9 18-0 11-5 



o 12-3 14-8 12-1 



8 10-1 12-1 10-7 



From this day onward the nitrogen excretion remains more 

 or less constant until just before death, when there occurs a sudden 

 rise. The explanation is that the animal is living on a minimum 

 amount of its own protein, and getting nearly all its energy for the 

 first day or so from its store of carbohydrate, and subsequently from 

 its body fat. This conclusion is reached by measuring the heat loss 

 and by ascertaining the respiratory quotient, and calculating from 

 this how much carbohydrate and how much fat are being metabolized. 

 It is possible, since starving animals and man give a low respiratory 

 quotient, that some of this fat may first be changed to carbohydrate 

 and metabolized in this fashion. It is difficult, however, to say exactly 



