554 



JOHtf K. MtTRLIN 



The method of Alim-entary Calo rime try consists then simply of findin^ 

 the average daily ingestion in terms of protein, fat and carbohydrate and 

 multiplying by the standard physiological heat values. Thus Gautier(fr) 

 gives the average dietary of a middle class Parisian as 102 grams protein, 

 50 grams fat and 400 grams carbohydrate. His average energy utilization, 

 therefore, would be: 102 X 4.1 + 56 X 9.0 + 400 X 4.1 = 2562 Calor- 

 ies. If a person on this diet were in equilibrium of nitrogen and weight, 

 his energy production would be equal to this sum ; otherwise not. Besides, 

 weight is not a satisfactory criterion of energy equilibrium and the utiliza- 

 tion when the diet is made up of different articles will vary considerably. 

 All we are justified in saying, therefore, is that an average regimen of this 

 sort represents such and such an energy value to the body. Some persons 

 would gain in weight on it ; others would lose. Another example is the fol- 

 lowing taken from the nutritional surveys of Army Camps in the United 

 States made by the Medical Department of the Army in 1918 (Murlin and 



Miller). 



TABLE 1 



NUTRIENTS AND ENERGY CONSUMED IN TRAINING CAMPS OF U. S. ARMY 



The "Fuel value consumed" in this and similar tables gives the energy 

 value to the body of the food consumed and not the amount of energy re- 

 leased by the body. Upon the diet of the Army Camps in 1918, the aver- 

 age recruit gained nearly six pounds in weight during a period of five 

 months training, showing that the energy content of the food was consid- 

 erably more than sufficient to sustain the muscular activity of hard train- 

 ing and to maintain body weight. 3 



The actual heat production in any given case can be computed from the 

 physiological heat values just discussed provided the output of carbon and 

 nitrogen can be determined, and provided it be assumed that all of the 

 carbohydrate fed is burned before fat burns. This method of calculation 



German school of metabolism have adopted Rubner's values of 9.3; while French au- 

 thorities like Gautier and LeFevre have accepted the work of Atwater as equally con- 

 clusive with that of Ruhner and have adopted a mean value between the two authorities 

 of 9.0 Cal. per gram. Since the methods of calculating the actual heat production by 

 use of these values have been largely superseded by the method of thermal quotients 

 to be described in the next section, the controversy over these values has subsided. 



3 Kecruits fed in this way for '.several months have almost certainly a higher basal 

 metabolism (see page GOT) than civilians of the same initial weight and age, and it 

 is not yet certain that the benefit from the standpoint of muscular efficiency is com- 

 mensurate with the cost in superfluous metabolism. This is a problem which requires 

 caieful study by the army itself. 



