NATIONAL FOOD CONSUMPTION. 



221 



cause there will inevitably be, in fact, a margin between actual gross 

 consumption and net physiological ingestion or utilization. The 

 present study, through the figures summarized in Table XV. gives a 

 clearer and probably more nearly exact picture of what this margin 

 between net and gross consumption must be, in a population of the 

 habits of the American people, than has hitherto been available. It 

 may well be theoretically true that a man needs only 75 grams or 

 50 grams of protein per day to sustain life and health, but in actual 



Fig. II. Diagram showing the energy value in calories of the gross consump- 

 tion of human food, per adult man per day. 



