ENERGY FOR MAINTENANCE. 283 
CALORIC INTAKE NEEDED FOR WEIGHT MAINTENANCE. 
One of the fundamentally important features of this research was to 
find the caloric intake requirement at the lower weight-level, with a 
view to determining whether, when the body-weight is reduced, the 
caloric needs are reduced proportionately, or less or more? If the 
body-weight could be held at the lower level for a considerable period 
of time, such as several weeks or months, an accurate measurement 
of the caloric intake would give a true measure of the caloric output 
or daily need. With practically all of the men in Squad A at certain 
times during the diet restriction the weight was maintained at a lower 
level with approximate constancy, but in no instance were these 
periods of weight maintenance of sufficient length to establish abso- 
lutely the true caloric needs. Although we were not able to hold 
the men at the lower weight-level for a sufficiently long time to 
determine definitely the caloric needs, further evidence may be 
obtained from the results of the gaseous metabolism experiments, which 
will be considered in a succeeding chapter. The period of diet restric- 
tion with Squad B was too short to establish a lower weight level 
for these men. 
Reference has already been made, particularly in the discussion of 
the body-weight charts for Squad A, to the caloric intake at the dif- 
ferent periods of the experiment. These caloric intakes have been 
given in actual figures in the energy tables for the individual subjects. 
Very considerable variations in the calories for each day were observed, 
which were due not only to irregularity in the character and amounts 
of food served from day to day in the dining hall but to the unre- 
stricted days, i. e., the uncontrolled Sundays. These latter were 
entirely beyond our control, other than as previously outlined at 
several points in this discussion. In preparing the estimate of the 
average caloric intake, however, we have invariably included the 
estimates based upon the reports of the men of the quantities of food 
eaten on the unrestricted Sundays, as given in table 34. (See p. 270.) 
It was necessary in our final tables to assume that on the first unre- 
stricted Sunday, October 14, the quantities taken were exactly those 
on the second unrestricted Sunday, the estimates of which were fur- 
nished by the men. No information is at hand in regard to the energy 
intakes during the Thanksgiving and Christmas recesses. Hence 
a break must occur in the caloric intake shown on the body-weight 
charts at these points. 
An analysis of the relationship between the caloric intake and the 
body-weight, and particularly the body-weight at maintenance level, 
may be made either from the tables showing the balance between the 
income and outgo, or from the body-weight charts. It is perhaps 
somewhat more satisfactory to study the subject graphically from the 
body-weight curves by noting the heights of the various blocks which 
