DIETARIES AND RATIONS. 13 



Diet and Work. It has been calculated from the results of 

 numerous analyses of common and efficient dietaries, and by 

 means of direct experiments with artificially constructed rations, 

 that an adult man weighing 140 to 150 Ibs. requires per day about 



Albuminoids ... ... ... ... 4'i6 oz. 



Oil or Fat 3'is 



Starch 14*29 



These are the figures used by Forster and Voit : they 

 correspond to about 282 grains of nitrogen and 5060 grains of 

 carbon. For reasons connected with the smaller body-weight of 

 native Indians, with the climate, and with the special vegetable 

 diet of the East, we have reduced and modified these amounts 

 to some extent in the examples of standard rations given later on. 



It may be interesting and useful to state here that the amount 

 of actual energy expressed in calories or heat-units which the 

 above standard diet is capable of setting free is calculated to be : 



4'i6 ozs. Albuminoids give 503,034 



3'i2 Fat or Oil ,, 801,699 



14-29 Starch 1,534,600 



2,839,333 Total Calories. 



These figures are approximations only, but they serve to show 

 that there is a large difference between the amounts of energy 

 expressed as heat which the three nutrients above-named can set 

 free, fat being more energetic than albuminoids, and albuminoids 

 more energetic than starch. The most recent experiments lead 

 one to the conviction that i part of vegetable oil or fat is 

 practically equal to 2-3 parts of starch : we accordingly use 2-3 as 

 the " starch-equivalent " of one part of oil. 



The heat which could be set free by the oxidation of the 

 nutrients in a day's ration is partly transformed into its mechanical 

 equivalent of work. The mutual convertibility of and quantitative 

 relation between work and heat is generally expressed by saying 

 that i Ib. of water is heated i Fahr. by the amount of actual 

 energy which is sufficient to raise 772 Ibs. to a height of i foot. 

 The amount of work done in and by the human body demands 



