INCOME AND OUTGO 337 



When we speak of the calorific value of a ration we 

 are assuming perfect absorption. Of course this in- 

 volves an error but not a large one. One often hears 

 the suggestion that a certain person "gets more of the 

 goodness from his food" than does another. There is 

 little 'evidence in support of this judgment unless the 

 second individual is a victim of chronic diarrhea. Lec- 

 turers and writers may carelessly assert that it is possible 

 by some system prolonged mastication, it may be 

 to improve the assimilation "by 50 per cent." or "100 

 per cent." The ordinary efficiency of the digestive 

 system is such that an improvement of 3 or 4 per cent, 

 is the most that is even conceivable. 



Proportions of the Foods. It has been said that the 

 free selection of foods to supply the needs of the day 

 is likely to lead to the inclusion of about 75 grams of 

 protein. The foods chosen will usually give about the 

 proper number of Calories, and since 75 grams of protein 

 furnish a little over 300 it will be seen that an average 

 of about 2000 Calories must be represented by carbo- 

 hydrate and fat. The fat in freely selected food will 

 not often exceed 100 grams a day. It will in many cases 

 be much less, perhaps no more than 50 grams. The 

 calories from 50 grams of fat will be about 465, from 100 

 grams about 930. In round numbers, then, the carbo- 

 hydrates of the ration must furnish from 1000 to 1500 

 Calories. From 250 to 375 grams of starch and sugar 

 will answer the purpose. 



The following combination may be considered a 

 common type of ration : 



Protein 75 grams or 300 Calories. 



Fat 50 grams or 465 Calories. 



Carbohydrate 375 grams or 1500 Calories. 



Total ' 2265 Calories. 



An indefinite number of combinations can be suggested 

 in which the protein and the total Calories shall be 

 constant. If, for example, the fat is increased to 100 

 grams we may have the items as below: 

 22 



