424 METABOLISM, NUTRITION, AND DIET 



what ways it is possible to obtain the requisite amount of nitrogen and carbon 

 from the most common food stuffs. 



In order to obtain the amount of proteid present from the proportion of 

 nitrogen, multiply by 6.25. 



From these data, or from the composition of foods on page 298, 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 f Ib. avoirdupois) lean uncooked meat *. . 10 grams 37 grams 



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



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 

 298 et seq.j 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: 



c. 



37 grams 

 168 " 



72 

 10 " 



19.0 grams 322 grams 



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

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

 and vegetables about 4 grams. 



The fluids should consist of about 2,500 to 2,800 grams, and might be 

 given as water, with or without tea, coffee, or cacao, which are chiefly 

 stimulants. 



The Energy Requirements of the Body. The food must not only 

 make up for the substances eliminated from the body but must also supply 

 the potential energy of heat and motion set free in the living body. The 



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

 proportionately less. 



