122 THE HYGIENE OF DIGESTION 



taken is excessive, however, the kidneys may becom" 

 overburdened, especially if they are weak or diseased, 

 The waste products then tend to clog or even to poison 

 the body. 1 



Tfmes for meals. The hours at which food is taken 

 depend a good deal upon the habits of peoples and of 

 individuals. In America, it is customary to have three 

 quite substantial meals a day. In determining what 

 practice is best for a given individual, the amount of 

 physical work to be done is the main factor. For the 

 man who is to do a morning's hard muscular work, a 

 substantial breakfast is essential, whereas lighter work 

 requires less food. The test in any case of whether 

 enough food has been taken is the person's condition 

 previous to the next meal. If he feels faint and ex- 

 hausted, with possible headache and even nausea, it 

 shows that his breakfast has been too scanty. He should 

 either have eaten more or have had a luncheon between 

 the two meals. If, on the contrary, he feels dull and 

 sluggish with little appetite for the next meal, he has 

 eaten too much. The same rules apply to the midday 

 meal. If a person is dull and sleepy after it, he should 

 eat more sparingly. At night, the meal should be com- 

 paratively light for children who go to bed soon after 

 it, in order that they may sleep soundly. For those who 

 are active for three or four hours afterwards, a hearty 

 meal may be necessary. The test of \vhether or not 

 the proper amount is eaten is the soundnes.s of sleep 

 and the appetite for breakfast. 



Appetite as a guide. For those who are active the 

 appetite is a guide as to when food should be taken and 



1 Experiments have shown that men can work to advantage on 

 about half as much proteid as the foregoing tables show, that is, 

 on from 50 to 70 gms. per day of dry proteid, which is the equiva- 

 lent of 200 to 300 gms. or 7 to 10 oz. of meat. 



