REQUISITES OF A NORMAL DIET 



451 



TABLE OF PERCENTAGES OF N AND C IN THE FOLLOWING SUBSTANCES. 



Bread 



Potat 



Eels. 



Mackerel 3-74 



Sardines in oil 6 . 



Butter o . 64 



19.26 



29. 



83- 



From these data, or from the composition of foods on page 323, it is pos- 

 sible to form various diet-scales which shall supply the needs of different 

 conditions of growth and decay of the body. Assuming that the average 

 amount of carbon and nitrogen required is about 300 grams and 20 grams, 

 respectively, this may be obtained as follows: 



N. C. 



340 grams (12 oz. or i Ib. avoirdupois) lean uncooked 



meat.* 10 grams 37 grams 



906 grams (32 oz. or 2 Ibs. avoirdupois) bread 9 grams 252 grams 



19 grams 289 grams 



But this diet is not the usual one; a certain proportion of the carbon is 

 usually supplied as butter, or bacon, and so if 90 grams of butter or bacon 

 be used it would supply about 72 grams of carbon, and the carbohydrate 

 would be diminished nearly one- third; but the nitrogen would also be di- 

 minished from 9 grams to 6 grams. It would be necessary to supply some 

 extra nitrogenous principle, which might be done by the addition of eggs, 

 milk, cheese, beans, or of any of the food-stuffs already enumerated at page 

 323 et seq., as supplying nitrogenous food chiefly. For example, 56 grams 

 (2 oz.) cheese contain, on an average, 3 grams of nitrogen and 20 grams of 

 carbon; or 28 grams cheese, containing 1.5 grams of nitrogen and about 

 10 grams carbon, together with 225 grams potatoes and 225 grams carrots, 

 supplying about i gram of nitrogen and 35 grams of carbon, may be added. 

 The diet would then read as follows : 



N. C. 



340 grams lean uncooked meat 10.0 grams 37 grams 



600 grams bread 6.0 grams 1 68 grams 



90 grams butter 0.5 grams 72 grams 



28 grams cheese 1.5 grams 10 grams 



225 grams potatoes 1 i.o grams 3 5 grams 



225 grams carrots, j 



19.0 grams 



322 grams 



The 30 grams of salts necessary to replenish the daily loss by excretion 

 in the urine are contained in the meat 16 grams, the bread 12 grams, and 

 vegetables about 4 grams. 



* As meat loses 23 to 34 per cent, in cooking, the weight of cooked meat would be 

 proportionately less. 



