Standards of the constituents of the urine and blood and the bearing of the metabolism of Bengalis on the problems of nutrition / by D. McCay.

  • McCay, David, 1873-
Date:
1908
Catalogue details

Licence: In copyright

Credit: Standards of the constituents of the urine and blood and the bearing of the metabolism of Bengalis on the problems of nutrition / by D. McCay. Source: Wellcome Collection.

    17/80 (page 9)
    The minimum average for durwans will be seen to be 2*61 grammes ; the maximum 930 grammes; the average amount of nitrogen eliminated on 36 daily analyses being 5'94 grammes. In the case of bearers, domes and mehtars similar figures were obtained, the average on 40 daily observations being 596 grammes. The average of nitrogen excretion over the whole series of 200 analyses comes to the small amount 5*98 grammes daily. This very small total nitrogen excretion in the urine of the Bengali is in marked contrast to the 15 to 18 grammes excreted by Europeans and, from a scientific point of view, forms one of the features of the results. It means the metabolism of only about 37*50 grammes of proteid daily by the Bengali—a minimum below that obtained by Chittenden in his different experiments. Even the average for five consecutive days in the case of the student who gave the highest results only comes to 56*50 grammes of proteid material meta- bolised per day ; the minimum being so low as 21*25 grammes. Chittenden was able after some months’ training to maintain himself in nitro- genous equilibrium on 37—40 grammes proteid daily; but, as Von Noorden states, “ All these experiments (Chittenden’s) have to be examined from another point of view—namely, from that of the individual who has to maintain himself in nitrogenous equilibrium on this daily dietary and for a long period.”(1) In the present observations we are dealing with individuals who had a per- fectly free choice of food and whose several conditions in life corresponded in every way to the great majority of the population of the country. We have, therefore, ideal conditions in which the lower limits of proteid metabolism is constantly present for an enquiry into the much discussed metabolic problem of the present day—the quantity of proteid in an ideal diet. To this we shall return in the second part of this paper. In the meantime it will suffice to point out that the total nitrogen in the urine being a measure of the proteid katabolism is also a measure of the nitrogenous material assimilated from the diet; so that we can calculate—-with a fair degree of accuracy—the total proteid value of the food of the different individuals and classes examined during the period they were under observation,, This value works out, on the average, to be about 37*50 grammes of assimilable, proteid intake in the 24 hours. Chittenden’s different groups were allowed quantities varying from 56, 63 to 67 grammes proteid daily, and on these they maintained a condition of nitrogenous equilibrium for many months. The figure 37*50 grammes represents only about 32 per cent, of Voit’s standard. [Volt's diet contains 118 grammes proteid.] (l) Von Noorden.—The Physiology of Metabolism. C