284 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



correspond to the caloric intake. (See figs. 57 to 68, pp. 210 to 222.) 

 In practically every instance the caloric intake was increased some- 

 what in the second week in December; in general the height of the 

 block at this time and the height of the block for the last few weeks 

 of the experiment are not far from the same. In other words, we 

 have two periods which represent a fairly close approximation to the 

 caloric intake for weight maintenance, i. e., when the body-weight was 

 either constant or not materially increasing or decreasing. At neither 

 of these times had we the perfect control desired. Nevertheless, these 

 two independent periods, some six weeks apart, give fairly good evi- 

 dence of the probable maintenance requirement of these men at the 

 lower weight-level. 



If we examine the body-weight chart for Bro, (fig. 57, p. 210), 

 we find that the initial requirement in the early part of this test on 

 the uncontrolled days was somewhat over 3,000 calories. The calories 

 here, as well as on the other charts, refer only to the net calories, 

 i. e., calories of food less those of feces and urine. On October 4 a 

 diet restriction took place with a fall in energy intake to about 2,200 

 calories. Further reductions were made but in the early part of 

 December the energy was increased. This increase was determined, 

 not by calculating the number of calories beforehand, but simply by 

 a gradual increase of the diet during this period until the body-weight 

 had become constant. Exactly the same procedure was carried out 

 in the latter part of January, but the assistant in charge of the ap- 

 portionment at no time determined the exact caloric intake of the 

 food. Thus, both of these levels were adjusted without a previous 

 knowledge of the caloric requirement. This holds true for all of the 

 subjects. On the return of the men to college in January, all of 

 the subjects received a low diet for a short time, to compensate 

 for the increase in body-weight during their absence. With Bro we 

 find that the average of the period of maintenance diet in December 

 and January is not far from 2,000 calories. Reference to the indi- 

 vidual balance-tables (tables 46 to 58) confirms this. To make the 

 details still clearer, an abstract is given in table 35 of the principal 

 data in the several balance-tables, grouped with regard to the several 

 periods of diet ingestion. Reference to the actual energy available 

 to the body with Bro during the period from December 3 to 20 shows 

 that he had 2,091 calories, and from January 16 to February 3, 1,931 

 calories, making an average for the two periods of 2,011 calories per 

 day. Hence, we may argue that Bro at the lower weight-level 

 required 2,000 net calories. 



The body-weight chart of Can (see fig. 58, p. 212) likewise shows 

 that during December there was an approximate period of maintenance 

 and another similar period in January. From table 35 and from the 

 height of the two energy blocks on Can's chart which, as stated before, 



