696 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



seen that the basal heat per 24 hours was 1,367 calories. On these days 

 there was an average gross intake of 2,486 calories. It has been found 

 by Dr. T. M. Carpenter,^ of this Laboratory, in recent extensive 

 research, that an average figure for the excess heat resulting from the 

 ingestion of mixed diet is 6 per cent of the gross energy intake. This 

 may be stated to be the "cost of digestion." Under these conditions 

 149 calories represents the "cost of digestion" for this period. 



As outlined in previous sections, the basal metabolism assumes the 

 individual to be lying down without food in the stomach. The extra 

 heat due to the ingestion of food has already been accounted for as 

 "cost of digestion." From the carefully kept records of these men, 

 the number of hours during which they were sitting has been recorded 

 and averages 11 hours for these 3 days. While many writers ascribe 

 no value to the difference between lying and sitting positions, particu- 

 larly if the subject be carefully adjusted in a steamer chair, it seems 

 reasonable to consider 10 per cent as a probable factor for the increase 

 in the metabolism, this being substantiated by a large amount of 

 experimental evidence.^ The per hour figure for the basal value is 57 

 calories; 10 per cent of this value, multiplied by 11 hours, will therefore 

 give 63 calories for the extra heat output due to the sitting position. 



From the pedometer records these men showed an average mileage 

 of 6.7 miles per day for the 3 days (January 30 and 31 and February 1). 

 Extensive data on the energy requirements for horizontal walking, 

 secured in the treadmill experiments (see p. 533) give accurate figures for 

 computing the average caloric requirement for walking 1 mile. It has 

 thus been found that the extra energy above basal for walking 1 mile 

 would mean, at this stage of the diet restriction, 56 calories. This 

 multiphed by the daily mileage of 6.7 miles equals 375 calories for 

 the activity of walking. 



In addition to the walking, the men reported on the average about 

 1 hour exercise more active than walking. With this factor we must 

 make several rather debatable assumptions. An examination of the 

 protocols shows that the men not infrequently included in this exercise 

 certain of the simpler gymnastic exercises, such as were shown in the 

 moving pictures, etc.; also other work which usually calls for severe 

 work for short periods but relatively long periods of rest. These activ- 

 ities were recorded as work greater than walking. It seems to us 

 reasonable to assume for this exercise an increased output of heat above 

 basal amounting to 400 per cent. The basal value was 57 calories per 

 hour; 400 per cent of this for 1 hour would therefore amount to 

 228 calories. 



iBenedict and Carpenter, Carnegie Inst. Wash. Pub. No. 261, 1918, p. 343. 

 ^Emmes and Riche, Am. Journ. Physiol., 1911, 27, p. 406; also Soderstrom, Meyer, and Du 

 Bois, Arch. Intern. Med.. 1916, 17, p. 872. 



