THE ENERGY REQUIREMENTS OF THE BODY 479 



Area = Weight - 425 X Height - 725 X Factor 71.84. 



The area is more quickly determined from the height-weight-graph 

 computed also by DuBois and DuBois. 



The amount of heat evolved by the oxidation of various food stuffs has 

 been carefully measured by numerous observers; the figures calculated by 

 Rubner are perhaps most satisfactory. 



HEAT VALUE TO THE BODY. 



i gram carbohydrate 4.1 Calories. 



i gram fat 9.3 Calories. 



i gram protein 4.1 Calories. 



One gram of dry protein has a total heat value of 5.754 Calories (Rubner), 

 hence it is obvious that protein is not completely oxidized by the body. Each 

 gram of protein yields at least one-third of a gram of urea, which has a heat 

 value of 2.5 Calories per gram. 



Atwater and Benedict have checked the energy value of the foods 

 actually consumed against the actual liberation of heat and work energy of 

 the human body. They find a wonderfully close agreement both for 

 periods of rest and for periods of work. Atwater's estimate for the energy 

 needs of man are as follows : 



Man without muscular work 2,700 Calories. 



Man with light muscular work 3,000 Calories. 



Man with moderate muscular work 3,5 Calories. 



Man with severe muscular work 4, 500 Calories. 



The daily output of energy for the adult man is as follows: 



Kilogrammeters. Calories 



Work of heart per day 88,000 



Work of respiratory muscle 14,000 



Eight hours' active work 213,344 



315,334 or 743 



Amount of heat produced in 24 hours 1,582,700 or 37 2 4 



1,898,034 or 4,467 



This estimate is relatively high for ordinary activity as determined by 

 Atwater and others. It is indeed more energy than the standard diets in 

 the table given on page 450 will yield to the body. For example, Voit's 

 diet yields 3,055 Calories, and the average of the table is only 3,125 

 Calories. 



