THE HYGIENE OF NUTRITION 361 



enema encourages the absorption of water and increases 

 the volume of the urine. Irrigation of the colon is 

 accordingly helpful when it is desired to promote 

 elimination by the kidneys, as in some cases classed as 

 rheumatism and arthritis. 



Obesity. Increase of adipose tissue can occur only 

 when the income of the body is for some time in excess 

 of the fuel requirement. This is a plain fact, but one 

 which is not always recognized. It would seem to 

 follow that such increases could be counteracted either 

 by restricting the diet or by speeding up the oxidation. 

 Both objects are often sought. If the food is limited 

 the weight must diminish. When we are not eating or 

 drinking we are necessarily losing weight at the rate of 

 at least an ounce an hour. But fasting is not pleasant 

 and insufficient feeding may be even more distressing. 



The consumption of adipose tissue may be forced by 

 exercise. A common difficulty is that the appetite is 

 so stimulated that unless it is sternly curbed the accumu- 

 lation is at once replaced. The victim has his labor for 

 his pains. We have made a brief reference to the power 

 of thyroid extracts to accelerate the metabolism and to 

 the use of these preparations in medicines for weight 

 reduction. They are not ideal for the purpose since 

 they produce nervousness and disturbances of the heart 

 action. 



The choice of a diet containing an unusual quantity 

 of protein has been recommended for the purpose of 

 cutting down the weight. The old theory was that 

 protein could make muscle but not fat, an idea favored 

 by the leanness of carnivorous animals. We have been 

 brought to believe that fat can be made from protein, 

 with sugar as an intermediate stage. The effect of a 

 high protein diet can be explained as due to two factors. 

 In the first place, it is likely to be satiating and the 

 amount eaten is automatically reduced without any 

 suffering from hunger and faintness. In the second 

 place, protein, more than other types of food, stimulates 



