218 HANDBOOK OF PHYSIOLOGY. 



consumption ; but no doubt after a time the organs, especially the liver 

 upon which the extra amount of the ingested diet throws most of the 

 stress, will yield to the strain of the over-work, and will not reduce the 

 excess of nitrogenous material brought to it into urea, but into other 

 less oxidized products, such as uric acid ; general plethora, and gout 

 being the result. This state of things, however, is delayed for a long 

 time, if not altogether obviated, when large meat-eaters take a considera- 

 ble amount of exercise. 



Excess of carbohydrate food produces an accumulation of fat, which 

 may not only be an inconvenience by causing obesity, but may interfere 

 with the proper nutrition of muscles, causing a feebleness of the action 

 of the heart, and other troubles. The accumulation of fat is due to the 

 excess of carbohydrate being stored up by the protoplasm in the form of 

 fat. Starches when taken in great excess are almost certain to give rise 

 to dyspepsia, with acidity and flatulence. Excess of starch or of sugar 

 in the food may, however, be got rid of by the urine in the form of gly- 

 cosuria. There is evidently a limit to the absorption of starch and of 

 fat, as, if taken beyond a certain amount, they appear unchanged in the 

 faeces. 



Requisites of a Normal Diet. 



It will have been understood that it is necessary that a normal diet 

 should be made up of various articles, that they should be well cooked, 

 and that they should contain about the same amount of carbon and ni- 

 trogen as are got rid of by the excreta. No doubt these desiderata may 

 be satisfied in many ways, and it would be unreasonable to expect that 

 the diet of every adult should be unvarying. The age, sex, strength, and 

 circumstances of each individual must ultimately determine his diet. A 

 dinner of bread and hard cheese with an onion contains all the requisites 

 for a meal, but such diet would be suitable only for those possessing 

 strong digestive powers. It is a well-known fact that the diet of the 

 continental nations differs from that of our own country, and that of 

 cold from that of hot climates, but the same principle underlies them all, 

 viz., the replacement of the loss of the excreta in the most convenient 

 and economical way possible. Without going into detail in the matter^ 

 it may be said that any one in active work requires more nitrogenous 

 matter than one at rest, and that children and women require less than 

 adult men. 



The quantity of food for a healthy adult man of average height and 

 weight may be stated in the following table: 



