92 NUTRITION. 



equilibrium." But at the same time the animal may increase in 

 weight, and this occurs by the formation of fat which is stored up 

 in the tissues. The nitrogenous equilibrium is more easily main- 

 tained by the addition of carbohydrates to the food. 



What is the effect of starvation upon the body ? 



There is a loss of weight in all the tissues, but it is in the loss of 

 the fat that the change is most marked : the fat almost entirely 

 (93 per cent.) disappears after death from starvation. The sense 

 of hunger gives way to a sense of pain ; thirst is excessive ; sleep 

 is absent ; progressive weakness accompanies increasing emaciation ; 

 the exhalations of the skin and lungs are foatid ; and diarrhoea with 

 convulsions or delirium often precedes death. Death occurs with 

 absolute deprivation of both food and drink at the end of about a 

 week (six to ten days), though life may be considerably prolonged 

 by small quantities of food or water. The temperature of the body 

 falls before death very considerably (30 C.), and it has been con- 

 sidered that death resulted from cold, no fuel being furnished to 

 maintain animal heat. The body decays rapidly after death from 

 starvation. 



What is the effect of an exclusive diet ? 



The result of feeding animals exclusively on a single article of 

 diet (sugar, gum, oil, etc.) is practically the same as that of star- 

 vation, except that death does not occur until the end of four or 

 five weeks. In man the exclusive diet of isolated communities 

 often results in the breaking down of tissue and general malnu- 

 trition. 



What is the effect of over-feeding ? 



An excess of nitrogenous food, if digested, increases the meta- 

 bolic work of the glandular organs (especially of liver and kidneys), 

 and induces disease in those organs and faulty excretion of nitrog- 

 enous matter. This may be obviated or delayed by active physi- 

 cal exercise. Carbohydrate food in excess is stored up in the form 

 of fat, which may be excessive, with resulting fatty infiltration of 

 the viscera, or it may show as glycosuria. 



An excess of a-ny food is apt to pass undigested through the intes- 

 tines and undergo putrefactive changes, with resulting gaseous 



