SUMMARY OF RESULTS. 687 



SUMMARY OF RESULTS AND GENERAL CONSIDERATIONS. 



From the large mass of data that we have attempted to analyze in 

 this report, certain very striking factors stand out above all others. 

 While on the reduced diet these men underwent profound metabolic 

 changes, which were indicated not simply by the losses in weight but 

 also by alterations in pulse-rate, in blood pressure, to a slight extent 

 in respiration rate, and more especially in the gaseous metabolism. 



CAUSE FOR DEPRESSION IN METABOLISM. 



The depression in the total metabolism is, without doubt, the most 

 prominent feature of the entire research, particularly as it was accom- 

 panied by a depression in other physiological factors, such as blood 

 pressure and pulse-rate. Loewy and Zuntz^ also noted a lowered 

 metabolism and give two possible explanations of it. One was that 

 the depression may have been wholly due to a lowered protein intake, 

 the other that there may have been a very considerable decrease in the 

 active cell-substance. The first of these two hypotheses they dismiss, 

 because Loewy, from the nitrogen excretion of the urine, showed that 

 he was living upon a distinctly high nitrogen level. The explanation 

 of Loewy and Zuntz thus rests solely upon the hypothesis that there 

 was a considerable loss of active cell-substance, and they conclude that 

 when the protein content of the diet is large and the caloric intake is 

 insufficient it is impossible to prevent the disintegration of active body- 

 substance. None of our men happened to have as high a nitrogen 

 excretion as that of Loewy, but with some it was fairly large and with 

 others fairly small. Consequently we do not believe that the protein 

 intake of itself played any particular role in this case. Loewy and 

 Zuntz naturally lacked demonstration of the loss of protein from the 

 body. 



One of the possible explanations of this lowered metabolism is that 

 with a weight-loss there is less work for the musculature to perform in 

 its ordinary activities — less weight to be lifted and less weight to be 

 moved. This may even apply in the case of respiratory and heart 

 muscles. A lower metabolism as a result of reducing the load to be 

 moved would therefore be expected. 



A second possible explanation is that with the reduction in diet, and 

 consequent loss of body-weight, there may be a removal of fat from the 

 tissues of the cells that makes the muscles somewhat more flexible, 

 capable of more severe work and greater efficiency. This is perhaps 

 in part comparable to a certain phase of athletic training, which com- 



^Loewj' and Zuntz, Berl. klin. Wochenschr., 1916, 53, p. 825. As this monogiaph goes into page 

 proof, our attention has been called to a second article by these authors (Zuntz and Loewy, 

 Weitere Untersuchungea iiber den Einfluss der Kriegskost auf den Stoffwechsel, Biochem. 

 Zeitschr., 1918, 90, p. 244), cited in an editorial in the Journ. Am. Med. Assoc, 1919, 72, p. 574. 

 We are not able to see the original article and in any event it is too late for its analysis in this 

 report. 



