Morris 7.03 ⎫
Steltz 7.13 ⎪
Broyles 7.26 ⎪
Loewenthal 7.38 ⎪
Oakman 7.42 ⎪
Fritz 7.84 ⎬ = 7.80 grams Nitrogen as
Cohn 8.05 ⎪ the grand average.
Coffman 8.17 ⎪
Zooman 8.25 ⎪
Sliney 8.39 ⎪
Henderson 8.91 ⎭
Bates 8.08—Oct. 27-Feb. 11.
Davis 8.61—Oct. 26-Jan. 12.
The figures given show an astonishingly low proteid metabolism for the
five months’ period; 7.5 grams of nitrogen in the day’s urine correspond
to 46.8 grams of proteid metabolized, while 8.5 grams of nitrogen mean
the metabolism of 53.1 grams of proteid. In other words, all of these
men during a period of five months practically averaged a daily output of
nitrogen through the kidneys corresponding to the metabolism of less than
one-half the 105 grams of absorbable proteid called for by the so-called
standard diets. Further, close scrutiny of the results in the individual
tables shows that during many weeks much lower results were obtained than
is indicated by the general averages.
Just here emphasis should be laid upon one fact, doubtless of primary
importance in any modification of the rate or extent of metabolism in any
individual, viz., that in this experiment the daily diet was prescribed,
thereby taking from the individual freedom of choice in the selection
of food. The writer has no question in his own mind that an intelligent
choice of food, coupled with the satisfying of a natural or acquired
appetite in moderation, will lead to better results than any system of
prescription as to what shall be eaten each day and in what quantity.
Still, this is the method necessarily made use of in the present
experiment, the writer having prescribed the character and amount of
each meal throughout the entire six months’ period, with due regard, of
course, to the expressed likes and dislikes of the men.
One feature in the diet compelled by the circumstances of the case
also needs to be referred to, namely, the necessity of keeping the men
thoroughly satisfied, so that there should be no feeling of hunger,
no craving for food. With a person interested in the experiment and
desirous of ascertaining the effect of a low nitrogen intake, there
would naturally be a willingness to endure, if necessary, for a time
some personal discomfort; but with this detail of the United States Army
it could not be expected that the men would remain satisfied if they
were compelled to undergo the pangs of hunger even for a day or two.
Consequently, it was necessary in prescribing the daily diet to see that
the quantity of the food was such as to completely satisfy the appetite.
This necessitated the use of considerable bulky food of low fuel, and low
nitrogen, value. In this way only was it feasible to reduce the nitrogen
intake, as well as the fuel value of the food, to the desired level.
Practically during the entire six months’ period, with the possible
exception of a few days, the men were given sufficient food to completely
satisfy their appetites. Throughout the entire period of the experiment,
the men all manifested a keen appetite and utilized their food to good
advantage, with establishment of the nitrogen metabolism indicated by the
foregoing results.
Still confining our attention to the average results regarding nitrogen
excretion, we may ask the question, what was the excretion of metabolized
nitrogen per kilo of body-weight in the different individuals? This is
easily calculated and the data are shown in the following table, in which
the figures standing for body-weight are either the data for the month of
April, 1904, or else the average between the October and April weights,
as in those cases where the body-weight fell off during the experiment.
Average daily Metabolized Nitrogen
Body-weight. Output of Nitrogen. per kilo
November-April. Body-weight.
kilos grams gram
Fritz 74.0 7.84 0.106
Oakman 64.0 7.42 0.116
Bates 68.0 8.08 0.118
Morris 59.0 7.03 0.119
Broyles 60.0 7.26 0.120
Henderson 71.0 8.91 0.125
Loewenthal 59.0 7.38 0.125
Cohn 63.5 8.05 0.126
Steltz 53.0 7.13 0.134
Sliney 60.0 8.39 0.138
Coffman 58.0 8.17 0.140
Davis 58.0 8.61 0.148
Zooman 55.0 8.25 0.150
Scrutiny of these results shows that the daily excretion of metabolized
nitrogen ranged in this period of five months from 0.106 gram per kilo
of body-weight up to 0.150 gram per kilo of body-weight. Since these
men were on essentially the same diet, it is obvious that there were
some peculiarities, or personal idiosyncrasies, that tended to modify
the exact extent of proteid metabolism, and in some cases at least
constituted a more potent factor than body-weight in determining the
rate of metabolism. This fact is clearly emphasized in the case of
Morris, who, with a body-weight of 59 kilos, showed a proteid metabolism
equivalent to only 7.03 grams of nitrogen per day, and Coffman, who, with
a body-weight of 58 kilos, showed under the same conditions an average
excretion of 8.17 grams of nitrogen per day.
What was the effect of this lowered proteid metabolism upon the bodily
condition, especially body-weight? To answer this question the weights
of the men are given in the following table, the one column of figures
showing the body-weight at the commencement of the experiment, the other
column showing the weight at the close of the experiment.