463 



to which 100 parts of fat are eqnivaloiit to 211 parts of albuminoids, and 

 100 parts of carboliydrates equivahMit to 88 parts of albuminoids. Cal- 

 culated on this basis, the protein-equivalents for the amounts of fat 

 and carbohydrates digested in excess of the average amount digested 

 in periods 1 and 7 (maintenance ration), woukl be for periods 2 and 6 

 as follows : 



Grams albuminoids. 



—0.63 grams fat X 2.11= 1.33 



— 3.89 grams carbohydrates X 0.88 3.42 



Total 4.75 



That is to say, the 0.63 grams of fat and 3.89 grams of carbohydrates 

 lost from the body were equivalent to 4.75 grams of protein. In the 

 same way, the fats and carbohydrates lost in periods 3 and 5 were 

 equivalent to — 1.64 grams of protein, and those gained in period 4, + 

 1.20 grams of protein. 



In order to determine the actual effect of the added protein, the cal- 

 culated protein equivalents must be subtracted from or added to the 

 excess of digested protein over that of the maintenance ration, as given 

 in the above table. This gives the actual excess of nutrients, expressed 

 in terms of protein (protein-equivalent), digested from the food during 

 periods in which protein was added, over that digested from the 

 maintenance ration fed in periods 1 and 7, as follows : 



Averages per anivial daily. 



Averages of periods. 



Excess of protein (protein- 

 equivalent) digested 

 when protein was added, 

 over that digested from 

 the maintenance ration 

 (periods 1 and 7). 



Excess of materials 

 laid on over those 

 with the mair.te- 

 nance ration (periods 

 1 and 7). 



Protein 



Fat. 



2 and 6 



3 and 5 

 4 



Grams. 

 (55.56—4.75=) 51.81 

 (113.54—1.64=) 111.90 

 (164.20+1.20=) 165.40 



Orams. 

 3.33 

 9.64 

 25.58 



Grams. 

 19.93 

 31.40 

 43.00 



For the 51.81 grams of protein (protein-equivalent) in excess of that 

 contained in the maintenance ration, 3.33 grams more protein and 19.93 

 grams more fat were stored in the body (laid on) than with the main- 

 tenance ration, etc. 



If the amount of protein laid on is subtracted from the amount 

 digested, the remainder would be the amount of protein which served to 

 lay on fat, and from this the amount of fat laid on for each 100 grams 

 of protein digested can be calculated by proportion. Thus, in periods 

 2 and 6 (51.81 — 3.33 = ) 48.48 grams protein produced 19.93 grams fat; 

 therefore, 48.48 : 19.93 : : 100 : 41.11 grams, or the amount of fat laid 

 on per 100 i)ounds of protein. A similar calculation gives the relative 

 aniounts of albuminoids and fat laid on for each 100 grams of i)roteiu 

 (protein-equivalent) consumed. 



