44 August Krogh and Marie Krogh. 



Summaiy. 



The normal diet of Eskimos contains an excessive amount of 

 animal protein (280 gr.) and much fat (135 gr.) while the quantity 

 of carbohydrate is extremely small (54 gr. of which more than % is 

 derived as glycogen from the meat eaten). Their dietary habits are 

 vey like those of the carnivorous animals. 



The diet does not appear to have any injurious effects whatever 

 upon the people. They are capable of prolonged work and extremely 

 enduring with regard to cold and hardships. Uric acid diseases are 

 very rare among them if they occur at all. 



In our feeding experiments made under absolute control within 

 the respiratory chamber we observed a maximum intake on one day 

 of 1804 gr. boiled seal meat, containing 85 gr. nitrogen and 218 gr. 

 fat, but this is far below the quantities recorded for Eskimos in the 

 free state. 



The large quantities of meat are well absorbed and utilized by 

 the Eskimos. The loss of nitrogen in the feces amounts to 3 — 5 gr. 

 per day and the loss of energy to less than 10 "/q of the food. 



The maximum quantity of nitrogen found in the urine of one 

 day was 53 gr. When meat was given after a diet poor in nitrogen, 

 only about 60 "/o of the nitrogen were excreted during the first 24 

 hours (from 5 hours after the first meal of meat to 18 hours after the 

 last), 40 7o (20—30 gr.) being retained. 



The urine curves show very distinctly the interdependence of 

 nitrogen and water excretion. During the nights after much meat 

 there is a retention of nitrogen and also of water until about 4 in the 

 morning but the quantity retained is excreted in bulk during the next 

 two (to three) hours. In this case we have undoubtedly a retention 

 of urea owing to decreased functional activity of the kidneys. 



For some of the subjects the urea + ammonia nitrogen has been 



, . ^, , . , ^, . urea + amm. N 



determined in 24 hour periods. The ratio ^-r^ varies 



^ total N 



with the total excretion between 83.6 7o (total TV 16.4 gr.) and 92.5 "/o 



(total N above 50 gr.). The variations in "endogenous" nitrogen are 



small (from 2 to 4 gr.). 



The respiratory exchange as determined in our experiments 

 varies irregularly during the day but is always higher during the 

 afternoon (from 2 to 10) than during the forenoon (6 — 2). During 

 the night it is almost constant and practically independent of the 



