Having considered the details of the metabolism experiments as recorded at the end of the 20 days of restricted diet, we are in a position to compare all the physiological activities and metabolic conditions with the normal period prior to dietetic restriction and to note the influence, if any, of the diet restriction. For this purpose we have drawn in table 141 an abstract of the important gaseous and heat measurements for all the members of Squad B at the two nutritional levels.

Table 140. - Increase In The Heat Output During Walking In Treadmill Chamber And The Computed Total Heat Required In Walking 10 Km. - Squad B, 20 Days Restricted Diet, January 28, 1918

1 Equivalent to 4.2 km. (2.6 miles) per hour, at rate of 70 meters per minute. 2 Computed; see page 535. 3Omitting Lon.

This table is primarily a comparison table and indicates, in the first place, the pronounced fall in weight which has been discussed in a previous section. All the men lost in weight, the smallest loss being that with Kim, amounting to but 2.3 per cent of his initial body-weight, and the largest with How, with 7.0 per cent of his body-weight. The uniformity of the mill is attested by the indication of no appreciable changes in distance walked per minute. The total heat output during standing and the increase above standing show a material falling-off during the 20-day test. As pointed out in a previous section, the decrease in heat output when standing was found with all subjects. The heat output above standing, i. e., that specifically involved in the work of walking, was decreased in all but 3 cases. A striking exception is the case of Fis, with whom there was an increase of 15.4 per cent; there were also increases with Har and Sne. The averages show a decrease from 2.95 calories on January 6 to 2.62 calories on January 28.

Table 141. - Comparison Of The Metabolism During Walking In Treadmill Chamber Of Squad B Normal On January 6, And On January 28 After 20 Days Restriction In Diet, With Per Cent Change From Normal

1 Computed; see pace 535.

2 Not included in average.

Of special significance is the total heat required for walking 10 km. This was almost always largely decreased, the two exceptions being the increase for Fis of 3.4 per cent and the insignificant change of 0.4 per cent with Sne. On the average these men as individual organisms were able to walk 10 km. at a very considerably reduced expenditure of energy. At the end of 20 days the average individual required for walking 10 km. a total of 535 calories. This is a decrease on the average of 87 calories in the total heat required in walking this distance, or approximately 14 per cent, and represents a real saving for the transportation of the individual over a given distance.

Owing to the unusual physiological interest in the efficiency of the human organism as a machine, the values for the heat per horizontal kilogrammeter have especial significance. It is seen that this value is in some instances increased and in others decreased. The most prominent increases are those of 19.7 per cent with Fis and 16.1 per cent with Sne. The most prominent decreases are those of 24.6 per cent with Kim, 27.9 per cent with Tho, 17.0 per cent with Wil, and 15.3 with Ham. It is extremely unfortunate that it is necessary to take the general picture from a series of observations that vary as widely as do these. Nevertheless, it seems reasonably clear that the average value found prior to reduction on the normal day of 0.592 when compared to the average reduction found on January 28 of 0.565 represents a real, though relatively slight, decrease. In brief, of the 11 subjects tested on the two days, 4 show an increase, 1 shows practically no change and 6 show a decrease in this factor.

From the average heat output with the subject standing and the heat output over and above standing shown in table 141, it is possible to compute approximately the distribution of the heat saving between the standing and walking requirements. It is seen that the decrease in the heat output for standing for the two dates was 0.27 calorie and the decrease in the heat output required on walking over and above that required for standing was 0.33 calorie. Of the total saving, then, of 0.60 calorie, that on the standing constituted 45 per cent and that on the walking 55 per cent. These figures have some interest, though the individual variations are wide. Six of the 11 subjects, however, showed that about 30 per cent of the saving was on the standing metabolism and 70 per cent on the walking metabolism.

While the reduction in body-weight in part explains the pronounced reduction of 14 per cent in the energy required for walking 10 km., it is of very great importance to note that not only were these men able to walk 10 km. at a very much less expenditure of energy than prior to their diet restriction, but that per unit of work done the figures for the horizontal kilogrammeter constants distinctly imply an increase in efficiency.