THE ENERGY OF THE METABOLISM 179 



60 per hour, an estimate adding up to 2080. It will be 

 suggestive if we consider how much of a single food-stuff 

 would be required to furnish a total of this order. 



Two thousand Calories could be obtained by the oxida- 

 tion of about 500 grams of starch or sugar. The meeting 

 ;Of the energy requirement is not the only qualification to 

 be demanded of a day's dietary. A ration of pure sugar 

 is obviously not to be recommended, though the consump- 

 tion of candy to such an extent may be entirely possible 

 for some subjects. The quantity of fat needed to afford 

 the same heat value will be in the vicinity of 216 grams. 

 One can hardly conceive of eating clear fat to this amount. 

 Making a similar calculation for alcohol, we find that a little 

 less than 300 grams of this compound will theoretically 

 meet the need. A palpable absurdity is apparent. While 

 the attempt to use alcohol exclusively as a fuel for the 

 body would evidently be disastrous, it is interesting to 

 consider that a lamp burning 300 grams of absolute alcohol 

 in a day would equal a human being as a source of energy. 

 The flame would be a very small one and the comparison 

 gives one a feeling of dissatisfaction and disappointment. 



Since protein is nearly equivalent to carbohydrate as a 

 source of energy, the theoretic ration of protein would be 

 the same as that of sugar, namely, 500 grams. The prac- 

 tical impossibility of eating so much protein is evident 

 when it is remembered that protein is acceptable only when 

 softened and expanded with liberal quantities of water. 

 Lean meat, which is not strictly a straight protein food, 

 but which approaches that composition, is three-fourths 

 water. White of egg, in which the solid portion is almost 

 all protein, is seven-eighths water. The attempt to dry 

 such material and so to reduce it to the smallest bulk 

 produces a mass resembling hardened glue or shellac. 

 To subsist on the proteins of meat alone, the fat having 

 been removed, one would be compelled to eat some five 

 pounds daily. Travelers have described certain peoples as 

 living almost wholly on meat or fish, but this does not mean 

 a pure protein diet, the fat undoubtedly figuring largely. 



