NUTRITION LABORATORY. 



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Table 1. — Illustrative results from psychological measurements during prolonged reduction 



in diet. 



amounting to about 5 per cent with the diet squad. The normal performance 

 of the control squad was not regular, which detracts from the significance of 

 the lengthening in the compared two low-diet sessions. The control and diet 

 squads show a decline in the number of finger movements with the reduced diet. 



Eleven men of the diet squad were pitted against an equal number from 

 the college body in an arm-holding contest for endurance. The arms were 

 held extended, palms down, at the level of the shoulders. The number of 

 men who did not endure to the end of the period was practically the same in 

 both squads; as a matter of fact, 7 men of the diet squad and 8 of the com- 

 peting squad were still holding out their arms in the prescribed manner 60 

 minutes after the trial started. Whatever one may think of this as a real 

 test of endurance, it is significant that the men who had been on reduced diet 

 for 4 months were not appreciably inferior. 



"Basing judgment on the more objective laboratory measurements, in 

 general it must be concluded that a prolonged reduction in diet produces 

 some dechne in neuro-muscular activities, but this does not seem nearly as 

 definite nor as large as the changes in metabohsm and allied measurements. 

 The psychological changes were not such as to materially interfere with a 

 satisfactory discharge of the common duties of student hfe." 



Of the various forms of muscular activity which might have been chosen 

 for a quantitative study of the efficiency of the human machine under a pro- 

 longed period of reduced diet, that of walking was selected, since it is the most 

 common and necessary exercise, the element of training is practically negligi- 

 ble, and the results can be expressed in common and well-understood terms. 

 The subjects were all required to walk upon a treadmill in a closed chamber 

 in which the respiratory exchange could be studied and the caloric output 

 computed from the results obtained. On January 6 the control squad was 

 studied prior to the diet restriction, and again on January 28 after 20 days 

 of low diet. With the diet squad, only one observation was made, that at 

 the end of the diet restriction, namely, on February 3. The results for the 

 heat required per man per kilometer during horizontal walking, without 

 taking into account the body-weight, are given in table 2. A marked 

 decrease in the total heat required for walking is shown as a result of the diet. 



