284 



THE METABOLISM OF FAT 



the fat, is undiminished. The depot fat is so much dead matter 

 an oil store which does not affect the composition of the living 

 bioplasm. 



Apart from the ash, the body consists essentially of proteid and 

 fat, for the capacity of the body to store carbohydrate is limited 

 to about 300 grm. of glycogen. The percentage composition of 

 fat practically the same in man and the domestic animals is 

 C, 76-5; H, 12; 0, 11*5. Thus in metabolism experiments a 

 gain of 100 grm. fat equals about 76 '5 grm. C, and a gain of 

 1 grm. C, as determined by the respiratory exchange, would 

 equal 1-f 0*765 = 1/307 grm. fat, while the respiratory quotient, 



CO 



-^- 2 , on a diet of pure fat calculated from the above percentage 



^2 

 composition, should approximate to '07. 



Adipose tissue itself holds about 30 per cent. H 2 0, a fact 

 which must be taken account of in calculating gain in body-weight 

 in metabolism experiments. 



In considering the relative fatness of a person 10-15 per cent, 

 under or above the average weights given below must be regarded 

 as normal, 15-30 per cent, above as fat, and 30-50 per cent, as 

 over fat. 



The average length and weight of body in the Teutonic race is 

 as follows : 



The more slender Latin race at twenty-five years has an 

 average of 1*680 m. and 62-93 kg. The average of woman at the 

 same age is 1-577 m. and 55-08 to 53'28 kg. 



The record weights of obese subjects are sufficiently startling ; 

 thus a fifteen-month child weighed 26*5 kg., a ten-year-old girl 

 109-5 kg., a man 304-5 kg., and another 490 kg. 



