FURTHER EXPERIMENTS AND OBSERVATIONS BEARING ON TRUE FOOD REQUIREMENTS
TOPICS: Dietary experiments with a detail of soldiers from the United
States army. General character of the army ration. Samples of the
daily dietary adopted. Rate of nitrogen metabolism attained. Effect
on body-weight. Nitrogen balance with lowered proteid consumption.
Influence of low proteid on muscular strength of soldiers and
athletes. Effect on fatigue. Effect on physical endurance. Fisher’s
experiments on endurance. Dangers of underfeeding. Dietary
observations on fruitarians. Observations on Japanese. Recent dietary
changes in Japanese army and navy. Observations of Dr. Hunt on
resistance of low proteid animals to poisons. Conclusions.
General acceptance of a new theory, or a new point of view, can be
expected only when there is an adequate amount of scientific evidence
on which the theory can safely rest. Facts cannot be ignored, and the
larger the amount of supporting evidence the more certain becomes
the general truth of the theory to which it points. Corroborative
evidence, therefore, is always desirable, and he who would open up a
new point of view must be zealous in accumulating facts to uphold his
position. Critics there are without number who are ever ready to pick
flaws in an argument or overturn a theory, especially if the one or
the other stands opposed to their own point of view. This, however,
is highly advantageous for the advance of sound knowledge, since it
necessarily prompts the advocate to search in all directions for added
data, by which he can build a bulwark of fact sufficient to defy just
criticism. Further, the true scientific spirit demands persistent
and painstaking effort in the search after truth, that error and
misconception may be avoided.
In harmony with these ideas, our attempt to ascertain the real needs of
the body for proteid food led us to enlarge our evidence by a series
of experiments with still another body of men, _i. e._, a detail of
soldiers from the United States army.[61] This was a somewhat more
difficult and ambitious undertaking, since the number of subjects
involved was larger, and because with this group of men we could not
expect quite that high degree of intelligent co-operation afforded by
the preceding subjects. Still, this very fact was in a sense an added
inducement, since it offered the opportunity of experimenting with a
body of men who naturally would not take kindly to anything that looked
like deprivation, and whose continued co-operation could be expected
only by satisfying their natural demands for food. If this could be
accomplished by an intelligent prescription in their daily diet, and
the experiment brought to a successful conclusion, with maintenance of
body-weight, nitrogen equilibrium, health, strength, and general vigor;
with an intake of proteid food essentially equal to that adopted by the
preceding subjects, corroborative evidence of the highest value would
be obtained.
[61] In presenting the general results of these experiments, the
writer has drawn freely from his book, “Physiological Economy in
Nutrition,” published by the Frederick A. Stokes Company, New York,
1904.
The detail was composed of a detachment of twenty men from the
Hospital Corps of the army, under the command of a first lieutenant
and assistant surgeon. They were located in a convenient house near
to the laboratory, where they lived during their six months’ stay in
New Haven, under military discipline, and subject to the constant
surveillance of the commanding officer and the non-commissioned
officers. Having well-trained cooks and assistants, with all necessary
facilities for preparing and serving their food, with members of
the laboratory staff to superintend the weighing of the food as it
was placed before the men, and with intelligent clerks to attend
to the many details connected with such an undertaking, a somewhat
unique physiological experiment was started. Thirteen members of the
detachment really took part in the experiment as subjects, and they
represented a great variety of types: of different ages, nationalities,
temperaments, and degrees of intelligence. They were men accustomed
to living an active life under varying conditions, and they naturally
had great liking for the pleasures of eating. Further, it should be
remembered that, although the men had volunteered for the experiment,
they had no personal interest whatever in the principles involved,
and it could not be expected that they would willingly incommode
themselves, or suffer any great amount of personal inconvenience.
Again, there were necessary restrictions placed upon their movements,
when relieved from duty, which constituted something of a hardship in
the minds of many of the men and added to the irksomeness and monotony
of their daily life. Regularity of life was insisted upon, and this
was a condition which brought to some of the men a new experience.
These facts are mentioned because their recital will help to make clear
that, from the standpoint of the men, there were certain depressing
influences connected with the experiment which would add to any
personal discomfort caused by restriction of diet.
The ordinary army ration to which these men were accustomed was rich in
proteid, especially in meat, and during the first few days they were
allowed to follow their usual dietary habits, in order that data might
be obtained bearing on their average food consumption. The details of
one day’s food intake will suffice to show the average character and
amount of the food eaten per man:
Breakfast.--Beefsteak 222 grams, gravy 68 grams, fried potatoes 234
grams, onions 34 grams, bread 144 grams, coffee 679 grams, sugar 18
grams.
Dinner.--Beef 171 grams, boiled potatoes 350 grams, onions 55 grams,
bread 234 grams, coffee 916 grams, sugar 27 grams.
Supper.--Corned beef 195 grams, potatoes 170 grams, onions 21 grams,
bread 158 grams, fruit jelly 107 grams, coffee 450 grams, sugar 21
grams.
It is not necessary to comment upon the large proportion of proteid
matter in the day’s ration; the three large portions of meat testify
clearly enough to that fact, while the three equally large volumes of
coffee indicate a natural disposition toward generous consumption of
anything available. Habit, reinforced by inclination, had evidently
placed these men on a high plane of food consumption.
For a period of six months, a daily dietary was prescribed for the
subjects; the food for each meal and for every man being of known
composition, each article being carefully weighed, while the content of
nitrogen in the day’s ration was so graded as to bring about a gradual
reduction in the amount of proteid ingested. The rate of proteid
katabolism was likewise determined each day by careful estimation of
the excreted nitrogen, balance experiments being made from time to
time in order to ascertain if the men were in a condition of nitrogen
equilibrium. Finally, it should be mentioned that the subjects lived
a fairly active life, having each day a certain amount of prescribed
exercise in the university gymnasium, in addition to the regular drill
and other duties associated with their usual work.
[Illustration: _Photograph of the soldiers taken at the close of the
experiment_]
[Illustration: _Photograph of the soldiers taken at the close of the
experiment_]
As just stated, the amount of proteid food was gradually reduced,
three weeks being taken to bring the amount down to a level somewhat
commensurate with the estimated needs of the body. This naturally
resulted in diminishing largely the intake of meat, though by no means
entirely excluding it. Effort was constantly made to introduce as
much variety as was possible with simple foods, though the main problem
with this group of men was to keep the volume of the food up to such
a point as would dispel any notion that they were not having enough
to eat. A second problem, which at first threatened trouble, was the
fear of the men, as they saw the proportion of meat gradually drop
off, that they were destined to lose their strength; but fortunately,
they very soon began to realize that their fears in this direction
were groundless, and a little later their personal experience opened
their eyes to possible advantages which quickly drove away all further
thought of danger, and made them quite content to continue the
experiment. We may introduce here a few samples of the daily food given
to the men after they had reached their lower level of proteid intake:
_January 15._
Breakfast.--Wheat griddle cakes 200 grams, syrup 50 grams, one cup
coffee[62] 350 grams.
Dinner.--Codfish balls (4 parts potato, 1 part fish, fried in pork
fat) 150 grams, stewed tomato 200 grams, bread 75 grams, one cup
coffee 350 grams, apple pie 95 grams.
Supper.--Apple fritters 200 grams, stewed prunes 125 grams, bread 50
grams, butter 15 grams, one cup tea 350 grams.
Total nitrogen content of the day’s food = 8.560 grams.
[62] The coffee was prepared with milk and sugar.
_January 16._
Breakfast.--Soft oatmeal 150 grams, milk 100 grams, sugar 30 grams,
bread 30 grams, butter 10 grams, one cup coffee 350 grams.
Dinner.--Baked macaroni with a little cheese 200 grams, stewed tomato
200 grams, bread 50 grams, tapioca-peach pudding 150 grams, one cup
coffee 350 grams.
Supper.--Fried bacon 20 grams, French fried potato 100 grams, bread
75 grams, jam 75 grams, one cup tea 350 grams.
Total nitrogen content of the day’s food = 7.282 grams.
_March 1._
Breakfast.--Fried rice 150 grams, syrup 50 grams, baked potato 150
grams, butter 10 grams, one cup coffee 350 grams.
Dinner.--Thick pea soup 250 grams, boiled onions 150 grams, boiled
sweet potato 150 grams, bread 75 grams, butter 20 grams, one cup
coffee 350 grams.
Supper.--Celery-lettuce-apple salad 120 grams, crackers 32 grams,
American cheese 20 grams, potato chips 79 grams, one cup tea 350
grams, rice custard 100 grams.
Total nitrogen content of the day’s food = 7.825 grams.
_March 3._
Breakfast.--Boiled hominy 175 grams, milk 125 grams, sugar 25 grams,
baked potato 150 grams, butter 10 grams, one cup coffee 350 grams.
Dinner.--Hamburg steak with much bread, fat, and onions 150 grams,
boiled potato 250 grams, bread 75 grams, butter 10 grams, one cup
coffee 350 grams.
Supper.--Tapioca-peach pudding 250 grams, bread 75 grams, butter 20
grams, jam 75 grams, one cup tea 350 grams.
Total nitrogen content of the day’s food = 8.750 grams.
_March 6._
Breakfast.--Sliced banana 100 grams, fried Indian meal 150 grams,
syrup 50 grams, baked potato 150 grams, butter 10 grams, one cup
coffee 350 grams.
Dinner.--Corned beef 50 grams, boiled cabbage 200 grams, mashed
potato 250 grams, bread 75 grams, fried rice 100 grams, jam 75 grams,
one cup coffee 350 grams.
Supper.--Crackers 32 grams, butter 10 grams, sardine 14 grams, sponge
cake 150 grams, apple sauce 150 grams, one cup tea 350 grams.
Total nitrogen content of the day’s food = 10.265 grams.
_March 30._
Breakfast.--Sliced banana 250 grams, fried hominy 150 grams, butter
10 grams, syrup 75 grams, one cup coffee 350 grams.
Dinner.--Codfish balls 125 grams, mashed potato 250 grams, stewed
tomato 200 grams, bread 35 grams, apple sauce 200 grams, one cup
coffee 350 grams.
Supper.--Chopped fresh cabbage with salt, pepper, and vinegar 75
grams, bread 50 grams, butter 20 grams, fried sweet potato 250 grams,
cranberry sauce 200 grams, sponge cake 50 grams, one cup tea 350
grams.
Total nitrogen content of the day’s food = 9.356 grams.
_March 31._
Breakfast.--Fried Indian meal 100 grams, syrup 75 grams, baked potato
250 grams, butter 20 grams, one cup coffee 350 grams.
Dinner.--Tomato soup, thick, with potatoes and onions boiled in, 300
grams, scrambled egg 50 grams, mashed potato 200 grams, bread 50
grams, butter 10 grams, one cup coffee 350 grams.
Supper.--Fried bacon 20 grams, boiled potato 200 grams, butter 10
grams, bread pudding 150 grams, sliced banana 200 grams, one cup tea
350 grams.
Total nitrogen content of the day’s food = 8.420 grams.
_April 1._
Breakfast.--Fried hominy 150 grams, syrup 75 grams, baked potato 200
grams, butter 20 grams, one cup coffee 350 grams.
Dinner.--Baked spaghetti 200 grams, mashed potato 250 grams, boiled
turnip 150 grams, bread 35 grams, butter 10 grams, apple sauce 200
grams, one cup coffee 350 grams.
Supper.--Fried bacon 25 grams, fried sweet potato 200 grams, bread
35 grams, butter 20 grams, jam 100 grams, apple-tapioca pudding 300
grams, one cup tea 350 grams.
Total nitrogen content of the day’s food = 7.342 grams.
These dietaries are fair samples of the daily food given the men
during the last five months of the experiment. If we place the intake
of nitrogen at 8.5 grams per day, or even 9 grams daily, it would
mean at the most an average daily consumption of 56 grams of proteid;
viz., about one-third the amount they were accustomed to take under
their ordinary modes of life. Of greater interest, however, is
the rate of proteid katabolism shown by these men under the above
conditions of diet, during the five months’ period. The average
daily output of metabolized nitrogen for each man ranged from 7.03
grams--the lowest--to 8.91 grams--the highest. An excretion of 7.03
grams of nitrogen per day means a katabolism, or breaking down, of
43.9 grams of proteid matter; while the excretion of 8.91 grams of
nitrogen corresponds to a katabolism of 55.6 grams of proteid. The
grand average, _i. e._, the average daily output of nitrogen of all
the men for the five months’ period amounted to 7.8 grams per man,
corresponding to an average daily katabolism of 48.75 grams of proteid.
The heaviest man of the group had a body-weight of 74 kilograms, while
his average daily output of metabolized nitrogen amounted to 7.84
grams. This corresponds to 0.106 gram of metabolized nitrogen per kilo
of body-weight; a figure which agrees quite closely with the lowest
figures obtained with the preceding subjects when calculated to the
same unit of weight. Many of the men, however, metabolized considerably
more nitrogen or proteid in proportion to their body-weight, due in a
measure at least to the fact that they were being fed more liberally
with proteid food than was really necessary for the needs of the body.
In this group, we have a body of men doing a reasonable amount of
physical work, who lived without discomfort for five consecutive months
on a daily consumption of proteid food not much, if any, greater than
one-third the amount called for by common usage, and the average fuel
value of which certainly did not exceed 3000 calories per day. Indeed,
so far as could be determined on the basis of chemical composition, the
heat value of the food was quite a little less than this figure would
imply.
If the relatively small amount of proteid food made use of in this
trial was inadequate for the real necessities of the body, some
indication of it would be expected to reveal itself, with at least some
of the men, by the end of the period. One criticism frequently made is
that the subject draws in some measure upon his store of body material.
Should this be the case, it is evident that body-weight--in such a
long experiment as this--will gradually but surely diminish. Further,
the subject will show a minus nitrogen balance, _i. e._, there will
be a constant tendency for the body to give off more nitrogen than it
takes in. As bearing on the first point, the following table showing
the body-weights of the men at the commencement of the experiment
in October, and at the close of the experiment in April will be of
interest:
TABLE OF BODY-WEIGHTS
+-------------+----------------+----------------+
| | October, 1903 | April, 1904 |
+-------------+----------------+----------------+
| | kilos | kilos |
| Steltz | 52.3 | 53.0 |
| Zooman | 54.0 | 55.0 |
| Coffman | 59.1 | 58.0 |
| Morris | 59.2 | 59.0 |
| Broyles | 59.4 | 61.0 |
| Loewenthal | 60.1 | 59.0 |
| Sliney | 61.3 | 60.6 |
| Cohn | 65.0 | 62.6 |
| Oakman | 66.7 | 62.1 |
| Henderson | 71.3 | 71.0 |
| Fritz | 76.0 | 72.6 |
| Bates | 72.7 | 64.3 (Feb.) |
| Davis | 59.3 | 57.2 (Jan.) |
+-------------+----------------+----------------+
As is readily seen, five of the men practically retained their weight
or made a slight gain. Of the others, Coffman, Loewenthal, Sliney, and
Cohn lost somewhat, but the amount was very small. Further, the loss
occurred during the first few weeks of the experiment, after which
their weight remained practically stationary. Fritz and Oakman lost
weight somewhat more noticeably, but this loss likewise occurred during
the earlier part of the trial. The accompanying photographs of Fritz,
taken at the close of the experiment, show plainly that such loss
of weight as he suffered did not detract from the appearance of his
well-developed musculature. Certainly, the photographs do not show any
signs of nitrogen starvation, or suggest the lack of any kind of food.
Of all the men, Bates was the only one who underwent any great loss of
weight. He, however, was quite stout, and the work in the gymnasium,
reinforced by the change in diet, brought about what was for him a very
desirable loss of body-weight. It is evident, therefore, that there was
no marked or prolonged loss of body-weight as a result of the continued
use of the low proteid diet. Regarding the second point, viz., nitrogen
equilibrium, the following illustrations will suffice to indicate the
relationship existing between the income and outgo of nitrogen. A
balance experiment with each of the men, lasting seven days, February
29 to March 6, is here shown, the figures given being the daily
averages for the period:
+-------------+----------+-----------+-------------+----------+
| | Nitrogen | Nitrogen | Nitrogen of | Nitrogen |
| | of Food. | of Urine. | Excrement. | Balance. |
+-------------+----------+-----------+-------------+----------+
| | grams | grams | grams | grams |
| Oakman | 9.52 | 7.24 | 1.76 | +0.52 |
| Henderson | 9.40 | 7.90 | 1.00 | +0.50 |
| Morris | 9.49 | 6.05 | 2.30 | +1.14 |
| Coffman | 9.53 | 7.92 | 1.47 | +0.14 |
| Steltz | 9.62 | 7.16 | 1.95 | +0.51 |
| Loewenthal | 9.64 | 7.00 | 1.71 | +0.95 |
| Cohn | 9.27 | 7.63 | 1.41 | +0.23 |
| Zooman | 9.49 | 7.13 | 1.76 | +0.60 |
| Sliney | 9.52 | 8.08 | 1.92 | -0.48 |
| Broyles | 9.43 | 7.01 | 1.19 | +1.23 |
| Fritz | 9.37 | 6.36 | 1.81 | +1.20 |
+-------------+----------+-----------+-------------+----------+
[Illustration: FRITZ
_At the close of the experiment_]
With one exception, all of the men were plainly having more proteid
food than was necessary to maintain the body in nitrogen
equilibrium, the plus nitrogen balance in most cases being fairly
large. It is only necessary to remember that a gain to the body of 1
gram of nitrogen means a laying by of 6.25 grams of proteid, and with
such a gain per day it is apparent that the men were really being
supplied with an excess of proteid food. This view is supported by the
fact that a later balance experiment, when considerably less proteid
food was being given, still showed many of the men in a condition
of plus balance, or with a minus balance so small as to indicate
essentially nitrogen equilibrium. The following figures, being daily
averages of a balance period about the first of April, may be offered
in evidence:
+-------------+----------+-----------+-------------+----------+
| | Nitrogen | Nitrogen | Nitrogen of | Nitrogen |
| | of Food. | of Urine. | Excrement. | Balance. |
+-------------+----------+-----------+-------------+----------+
| | grams | grams | grams | grams |
| Broyles | 8.66 | 6.63 | 1.87 | +0.16 |
| Fritz | 8.13 | 5.77 | 1.63 | +0.73 |
| Loewenthal | 8.51 | 6.51 | 2.02 | -0.02 |
| Steltz | 8.32 | 6.50 | 1.88 | -0.06 |
| Cohn | 8.29 | 6.25 | 1.55 | +0.49 |
| Morris | 8.45 | 6.49 | 2.27 | -0.31 |
| Oakman | 8.62 | 7.04 | 1.87 | -0.29 |
+-------------+----------+-----------+-------------+----------+
A daily intake of 8.5 grams of nitrogen means the consumption of
53 grams of proteid. Under these conditions of diet, the average
daily amount of nitrogen metabolized was 6.45 grams, corresponding
to 40.3 grams of proteid. The men were practically in a condition
of nitrogen equilibrium, so that we are apparently justified in the
general statement that the simple dietary followed with these men
during the six months’ experiment, and which was accompanied by an
average daily metabolism, after the first three weeks, of 7.8 grams of
nitrogen, was certainly sufficient to maintain both body-weight and
nitrogen equilibrium. Lastly, emphasis may be laid upon the fact that
these values for nitrogen do not necessarily represent the minimal
proteid requirement of the human body, since it is a well-established
physiological principle that by increase of non-nitrogenous food
the rate of proteid katabolism can always be further diminished; a
principle which is plainly in harmony with the view that a high rate of
proteid exchange is not a necessary requisite for the welfare of the
body.
The experimental results presented afford very convincing proof that
so far as body-weight and nitrogen equilibrium are concerned, the
needs of the body are fully met by a consumption of proteid food
far below the fixed dietary standards, and still further below the
amounts called for by the recorded habits of mankind. General health
is equally well maintained, and with suggestions of improvement that
are frequently so marked as to challenge attention. Most conspicuous,
however, though something that was entirely unlooked for, was the
effect observed on the muscular strength of the various subjects.
When the experiments were planned, it was deemed important to arrange
for careful quantitative tests of the more conspicuous muscles of the
body, with a view to measuring any loss of strength that might occur
from the proposed reduction in proteid food. The thought that prompted
this action was a result of the latent feeling that somehow muscular
strength must be dependent more or less upon the proteid constituents
of the muscles, and that consequently the cutting down of proteid food
would inevitably be felt in some degree. The most that could be hoped
for was that muscle tone and muscular strength might be maintained
unimpaired. Hence, we were at first quite astonished at what was
actually observed.
With the soldier detail, fifteen distinct strength tests were made
with each man during the six months’ period, by means of appropriate
dynamometer tests applied to the muscles of the back, legs, chest,
upper arms, and forearms, reinforced by quarter-mile run, vault, and
ladder tests, etc. The so-called “total strength” of the man was
computed by multiplying the weight of the body by the number of times
the subject was able to push up (strength of triceps muscles) and pull
up (strength of biceps muscles) his body while upon the parallel bars,
to this product being added the strength (dynamometer tests) of hands,
legs, back, and chest. It should be added that all of these tests were
made quite independently in the university gymnasium by the medical
assistants and others in charge of the work there. It will suffice for
our purpose to give here the strength tests of the various members of
the soldier detail at the beginning and close of the experiment.
TOTAL STRENGTH
+------------+----------+---------+
| | October. | April. |
+------------+----------+---------+
| Broyles | 2560 | 5530 |
| Coffman | 2835 | 6269 |
| Cohn | 2210 | 4002 |
| Fritz | 2504 | 5178 |
| Henderson | 2970 | 4598 |
| Loewenthal | 2463 | 5277 |
| Morris | 2543 | 4869 |
| Oakman | 3445 | 5055 |
| Sliney | 3245 | 5307 |
| Steltz | 2838 | 4581 |
| Zooman | 3070 | 5457 |
+------------+----------+---------+
Without exception, we note with all of the men a phenomenal gain in
strength, which demands explanation. Was it all due to the change in
diet? Probably not, for these men at the beginning of the experiment
were untrained, and it is not to be assumed that months of practical
work in the gymnasium would not result in a certain amount of physical
development, with corresponding gain in muscular skill and power.
Putting this question aside for the moment, however, it is surely
proper to emphasize this fact; viz., that although the men for a
period of five months were restricted to a daily diet containing
only one-third to one-half the amount of proteid food they had been
accustomed to, there was no loss of physical strength; no indication
of any physical deterioration that could be detected. In other words,
the men were certainly not being weakened by the lowered intake of
proteid food. This is in harmony with the principle, already discussed,
that the energy of muscle work comes primarily from the breaking down
of non-nitrogenous material, and consequently a diminished intake of
proteid food can have no inhibitory effect, provided, of course, there
is an adequate amount of proteid ingested to satisfy the endogenous
requirements of the tissues.
On the other hand, recalling the large number of nitrogenous cleavage
products which result from the breaking down of proteid material, we
can conceive of an exaggerated exogenous proteid katabolism which
may flood the tissues and the surrounding lymph with a variety of
nitrogenous waste products, having an inhibitory effect upon the
muscle fibres themselves, or upon the peripheral endings of the motor
nerves, by which the muscles are prevented, directly or indirectly,
from working at their highest degree of efficiency. This being true,
a reduction of the exogenous katabolism to a level more nearly
commensurate with the real needs of the body might result in a marked
increase in the functional power of the tissue. However this may
be, the fact remains that all of the subjects showed this great
gain in strength; and furthermore, there was a noticeable gain in
self-reliance and courage in their athletic work, both of which are
likewise indicative of an improved condition of the body. How far these
improvements are attributable to training and to the more regular life
the men were leading, and how far to the change in diet, cannot be
definitely determined. We may venture the opinion, however, for reasons
to be made clear shortly, that the change in diet was in a measure
at least responsible for the increased efficiency. As the writer has
already expressed it, there must be enough food to make good the
daily waste of tissue, enough food to furnish the energy of muscular
contraction, but any surplus over and above what is necessary to supply
these needs is not only a waste, but may prove an incubus, retarding
the smooth working of the machinery and detracting from the power of
the organism to do its best work.
Let us now turn our attention for a moment to the group of university
athletes, remembering that these men had been in training for many
months, and some of them for several years, prior to the commencement
of the trial with a reduced proteid intake. In the words of the
director of the gymnasium, “These eight men were in constant practice
and in the pink of condition; they were in ‘training form’ when they
began the changed diet.” Some of them had gained marked distinction for
their athletic work; one during the early months of the test won the
Collegiate and All-around Inter-collegiate Championship of America.
Compare now the strength tests of these men as taken at the beginning
and end of the five months’ experiment, during which they reduced their
daily intake of proteid food more than fifty per cent:
TOTAL STRENGTH
+----------------+----------+----------+
| | January. | June. |
+----------------+----------+----------+
| G. W. Anderson | 4913 | 5722 |
| W. L. Anderson | 6016 | 9472 |
| Bellis | 5993 | 8165 |
| Callahan | 2154 | 3983 |
| Donahue | 4584 | 5917 |
| Jacobus | 4548 | 5667 |
| Schenker | 5728 | 7135 |
| Stapleton | 5351 | 6833 |
+----------------+----------+----------+
It is to be observed that the majority of these trained men showed at
the first trial in January a total strength test approximately equal to
that of the soldier detail at the close of their experiment. This by no
means implies that the latter men owed their gain in strength wholly
to the systematic training they had undergone, but it is certainly
plausible to assume that in a measure this was the case. In any event,
it is plain that the long-continued low proteid diet of the soldiers
had not interfered with a progressive muscular development, and the
attainment of a high degree of muscular strength.
The noticeable feature in the figures obtained with the athletes,
however, is the striking difference between the January and June
results. Every man, without exception, showed a decided gain in his
muscular power as measured by the strength tests. This improvement, to
be sure, was not so marked as with the soldiers; a fact to be expected,
since with these men the element of training and the acquisition
of proficiency in athletic work could have played no part in the
observed gain. Further, most of the tests indicated that the gain was
progressive, each month showing an improvement, in harmony with the
growing effect of the diminished proteid intake. With these subjects,
the only tangible change in their mode of life which could in any sense
be considered as responsible for their gain in strength was the change
in diet. Consequently, it seems perfectly justifiable to conclude that
the observations presented afford reasonable proof of the beneficial
effects of a lowered proteid intake upon the muscular strength of man.
The significance of such a conclusion is manifestly obvious. It
confirms and gives added force to the observations that man can
profitably maintain nitrogen equilibrium, and body-weight, upon a
much smaller amount of proteid food than he is accustomed to consume.
It harmonizes with the view that the normal requirements of the body
for food, under which health, strength, and maximum efficiency are
best maintained, are on a far lower level than the ordinary practices
of mankind would lead one to believe. The widespread opinion that
a rich proteid diet, with the correspondingly high rate of proteid
metabolism, is a necessity for the preservation of bodily strength and
vigor, is seen to be without foundation; for even the most conservative
estimate of the real value of these strength tests must carry with
it the conviction that lowering the consumption of proteid food does
not at least result in any weakening of the body. This is a fact of
vital importance, for it needs no argument to convince even the most
optimistic that while it might be possible to maintain body-weight
and nitrogen equilibrium on a small amount of proteid food, such a
form of physiological economy would not only be of no advantage to
the individual, but would be positively injurious if there was a
gradual weakening of the muscles of the body with decrease of physical
strength, vigor, and endurance.
Another fact to be emphasized in this connection was the conviction,
gradually acquired by many of the subjects, that they suffered
less from fatigue after vigorous muscular effort than formerly.
This was especially conspicuous in the case of Donahue, whose work
on the Varsity basket-ball team called for vigorous exercise. It is
interesting to note that this athlete, of 63 kilos body-weight, for the
last four months of the experiment showed an average daily katabolism
of 7.45 grams of nitrogen, corresponding to a breaking down of 46.5
grams of proteid material daily. Yet, with this low rate of proteid
exchange, he maintained his position on the team with satisfaction to
all, and with the consciousness of improved physical condition and
greater freedom from fatigue. Other subjects, as the laboratory workers
of the professional group, observed that the customary late afternoon
fatigue, coincident with the continued walking and standing about the
laboratory, gradually became far less conspicuous than usual; so that
there seemed to be a consensus of opinion that in some way the change
in diet was conducive to greater freedom from muscular weariness.
It is well understood by physiologists that the ability of a muscle
to do work is inhibited by any condition that tends to depress the
general nutritive state of the body, or that interferes with the local
nutrition of the muscle or muscles involved. On the other hand, there
are certain well-recognized conditions that tend to augment the power
of the muscle, notably an increased circulation of blood through the
tissue, the taking of food, and especially the introduction of sugar.
Further, experiments have shown that when a given set of muscles has
been made to work excessively, other muscles of the body quite remote
will share in the fatigue, thus implying that muscular weariness and
the diminished power to do work are connected with what may be termed
fatigue products, which are distributed by means of the circulation. In
this way, muscles and nerve endings alike are exposed to the inhibitory
influence of waste products of unknown composition, formed in the
muscle, and as previously stated, we may conceive of an exaggerated
exogenous katabolism, with excessive proteid intake, by which muscular
fatigue and weariness may be augmented; hence, the beneficial effect in
this direction of a more rational food consumption, by which proteid
katabolism shall be reduced to a true physiological level.
With these marked effects on strength and fatigue, it is reasonable
to assume that some corresponding action may be exerted on physical
endurance. As is well known, strength and endurance, though related,
are quite distinct and can be separately measured. Strength tests,
however, as usually carried out in gymnasium work, do involve in
considerable degree the question of endurance, since it is customary to
use as one of the factors in estimating total strength the number of
times the man can pull up, or push up, his body on the parallel bars.
Strictly speaking, however, the strength of a muscle is measured by the
maximum force it can exert in a single contraction, while its endurance
is estimated from the number of times it can contract well within the
limit of its strength.
It is well known that endurance, both physical and mental, is one of
the most variable of the human faculties, and it is usually considered
that exercise or training is the chief cause of the differences so
frequently seen. The Maine guide will row a boat or paddle a canoe
for the entire day without undue fatigue, while the novice, though
he may have the necessary strength, lacks the endurance to continue
the task longer than a few hours. As expressed by Professor Fisher,
“Some persons are tired by climbing a flight of stairs, whereas the
Swiss guides, throughout the summer season, day after day spend the
entire time in climbing the Matterhorn and other peaks; some persons
are ‘winded’ by running a block for a street car, whereas a Chinese
coolie will run for hours on end; in mental work, some persons are
unable to apply themselves more than an hour at a time, whereas
others, like Humboldt, can work almost continuously through eighteen
hours of the day.” Again, Fisher states that “among some 75 tests
of different persons holding their arms horizontal, many were found
whose arms actually dropped against their will inside of 10 minutes,
whereas several were able to hold them up over 1 hour, and one man held
them 3 hours and 20 minutes, or a round 200 minutes, and then dropped
them voluntarily. Similarly with deep knee-bending, some persons were
found physically unable to rise again from the stooping posture after
accomplishing less than 500 bendings, whereas several succeeded in
stooping 1000 times, and in one case, 2400.” Here, we have inherent
differences in endurance not associated with training or exercise, and
the question may well be asked, What is the cause of these radical
variations in the ability to repeat a simple muscular exertion?
Hitherto, little attention has been paid to the possible influence of
diet upon this faculty. It has always been assumed that endurance,
like physical strength, is augmented by a rich proteid diet, but it
has never been considered that diet by itself was a factor of any
great moment as compared with training or persistent exercise. It is
true that claims have been advanced from time to time concerning the
beneficial effects on endurance of a vegetable diet, and vegetarians
have frequently presented glowing reports of the great increase in
endurance they have experienced, but little attention has been given to
such statements, and the matter has remained more or less in obscurity.
Recently, Professor Irving Fisher,[63] of Yale, has conducted an
interesting experiment on the influence of a change in diet on
endurance, having the co-operation of nine healthy students as
subjects. The experiment extended through five months, with endurance
tests at the beginning, middle, and end of the period. At the outset,
the men consumed daily an average of 2830 calories, of which 210
were in the form of flesh foods, such as meats, poultry, fish and
shell-fish; 2.6 calories of proteid being ingested for each pound of
body-weight. At the close of the experiment, the per capita calories
had fallen to 2220, of which only 30 were in flesh foods, and the
proteid had fallen to 1.4 calories per pound of body-weight. In other
words, the total calories of the daily ration had dropped off about 25
per cent, the proteid about 40 per cent, and the flesh foods over 80
per cent, or to about one-sixth of their original amount.
[63] Through the kindness of Professor Fisher, the writer has had the
opportunity of reading the report of this work, which at this writing
is not published, and he has drawn upon it freely for the following
statements of fact.
To determine the endurance of the subjects, six simple gymnastic
tests were employed, and one of mental endurance. The physical tests
consisted of (1) in rising on the toes as often as possible; (2) deep
knee-bending, or stooping as far as possible and rising to the standing
posture, repeating as often as possible; (3) while lying on the back,
raising the legs from the floor to a vertical position and lowering
them again, repeating to the point of physical exhaustion; (4) raising
a 5-lb. dumb-bell (with the triceps) in each hand from the shoulder up
to the highest point above the head, repeating to the point of physical
exhaustion; (5) holding the arms from the sides horizontally for as
long a time as possible; (6) raising a dumb-bell (with the biceps) in
one hand from a position in which the arm hangs free, to the shoulder
and back, repeating to the point of physical exhaustion. This test was
taken with four successive dumb-bells of decreasing weight, viz., 50,
25, 10, and 5 pounds respectively. The mental test consisted in adding
specified columns of figures as rapidly as possible, the object being
to find out whether the rapidity of performing such work tended to
improve during the experiment.
The following table shows the results of the three sets of physical
tests made in January, March, and June:
TESTS OF PHYSICAL ENDURANCE WITH THE NINE SUBJECTS
+-------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| |Time.| B. | E. | Lq. | Lw. | M. | P. | R. | T. | W. |
+-------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
|1. Rising on |Jan. | 300 |1007 | 333 | 69 | 127 |1482 | 702 | 900 |1263 |
| toes |Mar. | 400 |1265 |2620 | 65 | 400 | | 831 |1500 | |
| |June | 500 |1061 |3000 | 85 |1500 |1800 |1263 |1800 |3350 |
| | | | | | | | | | | |
|2. Deep knee-|Jan. | 82 | 142 | 70 | 48 | 132 | 208 | 374 | 129 | 404 |
| bending |Mar. | | | 191 | 47 | | | | | |
| |June | 200 | 81 | 202 | 58 | 155 | 230 | 453 | 250 | 508 |
| | | | | | | | | | | |
|3. Leg |Jan. | 25 | 52 | 9 | 22 | 30 | 27 | 50 | 23 | 30 |
| raising |Mar. | | | | 33 | | 34 | | | 40 |
| |June | 33 | 38 | 20 | 35 | 31 | 37 | 103 | 19 | 53 |
| | | | | | | | | | | |
|4. 5lb. |Jan. | 75 | 138 | 78 | 38 | 51 | 44 | 100 | 83 | 185 |
| Dumb-bell |Mar. | | | 106 | | | | | | |
| (triceps) |June | 127 | 59 | 80 | 51 | 75 | 56 | 104 | 101 | 501 |
| | |m. s.|m. s.|m. s.|m. s.|m. s.|m. s.|m. s.|m. s.|m. s.|
|5. Holding |Jan. | 5–0 | 1–33| 4–7 | 3–37| 3–30| 5–39| 2–5 | 3–22|11–0 |
| arms |Mar. | | | | | 5–49| | | |15–35|
| horizontal|June | 9–36| 2–56| 3–50| 3–0 | 6–5 |10–1 | 3–16| 3–24|23–45|
| | | | | | | | | | | |
|6. 25lb. |Jan. | 50 | 18 | 16 | 6 | 20 | 11 | 10 | 25 | 54 |
| Dumb-bell |June | 105 | 10 | 26 | 33 | 30 | 29 | 27 | 75 | 108 |
| (biceps) | | | | | | | | | | |
+-------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
The data presented show a marked improvement in March and June over the
record made at the beginning of the experiment in January, except in
the case of one subject, E. As Fisher states, the increased endurance
observed can be ascribed only to dietetic causes, since no other
factors of known significance could have aided in the result. The
dietetic changes, as we have seen, consisted in a slight reduction of
the total amount of food consumed daily, but with a large reduction of
the proteid element, especially from flesh foods. It is significant,
says Fisher, that the only man whose strength and endurance showed any
decrease was E, “whose case was exceptional in almost all respects.
His reduction in quantity of food, except for a spurt at the end, was
less than of most of the men; his reduction in proteid, with the same
exception, was the least of all; his reduction in quantity of flesh
foods was the least of all.” He stands out conspicuously as the one man
whose endurance failed to improve. The mental test carried out with the
subjects pointed to “a slight increase in mental quickness,” but the
adding test was too short to be of great value.
We see in these results another confirmation of the view that the
welfare of the body is not impaired by a marked reduction in the amount
of proteid food; on the contrary, benefit results in the increased
efficiency which manifests itself in various directions. Physical
endurance is an asset not to be ignored, and like the strength of an
individual, it may well be fostered by the recognition and practice of
a principle which seemingly has a firm physiological basis. Whether
the fatigue poisons come from the excessive exogenous katabolism of
proteids in general, or whether they are derived directly in a measure
from flesh foods, need not be considered here; the main point is that
by lowering the rate of proteid katabolism, which necessarily compels a
reduction in the amount of flesh foods, there is a diminished quantity
of nitrogenous waste floating about in the body. Further, we need
not criticise too closely the method by which the reduction of food
is accomplished; whether it be by encouraging mastication, with a
view to better tasting and fuller enjoyment of the food, to the point
of involuntary swallowing; or whether we follow natural taste and
appetite, reinforced by the use of reason, with a full appreciation
of the principle that the welfare of the body is best subserved by a
quantity of food commensurate with true physiological needs.
In making this presentation of the true food requirements of the
body as based on the results of physiological experimentation and
observation, I am by no means unmindful of the dangers of underfeeding;
but this is a condition comparatively rare. When occurring, as stated
by Dr. Curtis, “it is either because of dyspepsia, in which case it
really is involuntary, or comes from some silly notion born of a
combination of innate mental crookedness and that ‘little knowledge’
that is a dangerous thing.” Overfeeding is the predominant dietetic
sin, and with the prevailing dietary standards, as fixed by common
usage, there is good ground for believing that it will continue for
many years to come. Reason tells us, however, in the practice of our
personal nutrition, to steer a middle course between physiological
excess on the one side, and the minimal food requirement on the other.
To quote again from Dr. Curtis,[64] who has expressed the matter very
forcibly, “The physiological chemist can easily draw a line on the
Scylla (starvation) side of the channel. A dietary whereby the system
gets less than it pays out is, obviously, a dangerous veer toward
starvation rock. But on the Charybdis (stuffing) side, just as the
whirlpool itself has no well-defined border, the channel boundary is
not so easily marked. The case is exactly analogous to the stoking of
a furnace. The proportion of ash to live coals is a telltale as to
_under_feeding, but not as to _over_feeding. With undersupply of fuel
the ashes overbalance the live coals, and the fire is thus foretold to
be going out. But with an oversupply the fire simply burns the faster:
all the fuel continues to be consumed; the more coal simply makes the
more ash, so that equilibrium is not disturbed, although maintained
at a higher level. To argue, therefore, that a given dietary is none
too large, because the balance between the material receipts and
expenditures of the economy is not upset, would be like saying that a
given furnace-fire is certainly none too hot, since the ashes raked
out of the fire-box just correspond to the amount of coal shovelled
in. The same would be equally true of a slower fire consuming much
less fuel. The philosophy of the matter is, then, to find the minimum
of steam that will run the engine, and then maintain a fire somewhat
hotter than the exact requirement, in order to run no risk of failure;
or, to return to the metaphor already employed, the would-be careful
liver must simply note how close to Scylla other voyagers have sailed
with safety, and then steer his own bark accordingly.”
[64] Edward Curtis, M. D.: Nature and Health. New York, Henry Holt &
Co. 1906. p. 71.
As one looks through the many careful dietary studies that have been
made in recent years, it is easy to find striking illustrations of
people, and communities of people, who have lived for long periods
of time on dietaries so strikingly simple and meagre that it seems
difficult at first glance to believe their daily needs could have been
entirely satisfied. Yet, such observations are quite in accord with
the facts we have been presenting, and they afford additional evidence
that the artificial dietary standards that have been set up are widely
at variance with the real requirements of the body for food. It may
be quite true that many of the people referred to have been and are
faddists, with peculiar notions regarding food, based on religious or
other scruples, but that has no bearing on the main contention that
they have lived for many years on amounts of food ridiculously small
as compared with the ordinary customs of mankind. Thus, in Professor
Jaffa’s report[65] of investigations made among fruitarians and Chinese
of California is an interesting account of a dietary study of a family
of fruitarians, consisting of two women and three children. They had
all been fruitarians from five to seven years, their diet being limited
to nuts and fruit, except for the addition of celery, honey, olive
oil, and occasionally a small amount of prepared cereal food. This
family was in the habit of taking only two meals a day; at 10.30 in
the morning and at 5 o’clock in the afternoon. The first meal always
consisted of nuts and fruit, the nuts being eaten first. At the second
meal, nuts were usually replaced by olive oil and honey. The nuts made
use of were almonds, Brazil nuts, pine nuts, pignolias (a variety of
pine nuts), and walnuts. Fruits, both fresh and dried, were used,
the former including apples, apricots, bananas, figs, grapes, olives
(pickled), oranges, peaches, pears, plums, and tomatoes. The dried
fruits were dates and raisins.
[65] Bulletin No. 107, Office of Experiment Stations, U. S.
Department of Agriculture, 1901, from which the descriptions given
have been taken.
On this limited dietary of raw, uncooked food, with a complete absence
of the high-proteid animal foods, and the ordinary vegetables, legumes,
etc., and without eggs or milk, this family, with three growing
children, had lived all these years. Note now what Jaffa observed
regarding their food consumption. The first subject, a woman 33 years
of age and weighing 90 pounds, was studied for twenty consecutive days,
all the food eaten being carefully weighed and its chemical composition
determined. As a result, it was found that the average amount of food
consumed per day was: proteid, 33 grams; fat, 59 grams; carbohydrate,
150 grams; with a total fuel value of 1300 calories. The other members
of the family were studied in a similar manner, one of the children
being the subject on two separate occasions. The table (on page 217),
showing the average daily food consumption, gives a summary of the
results obtained.
+--------------------------------+--------+-----+------+--------+--------+
| | | | | |Proteid |
| | | |Carbo-| Fuel |per Kilo|
| |Proteid.|Fat. | hyd- | Value. | Body- |
| | | | rate.| |weight. |
+--------------------------------+--------+-----+------+--------+--------+
| | grams |grams|grams |calories| grams |
|Woman, 33 years old, | | | | | |
| Weight 90 lbs. (40.9 kilos) | 33 | 59 | 150 | 1300 | 0.80 |
|Woman, 30 years old, | | | | | |
| Weight 104 lbs. (47.3 kilos) | 25 | 57 | 90 | 1040 | 0.52 |
|Girl, 13 years old, | | | | | |
| Weight 75-1/2 lbs. (34.3 kilos)| 26 | 52 | 157 | 1235 | 0.75 |
|Boy, 9 years old, | | | | | |
| Weight 43 lbs. (19.5 kilos) | 27 | 56 | 152 | 1255 | 1.38 |
|Girl, 6 years old, | | | | | |
| Weight 30-1/2 lbs. (13.9 kilos)| 24 | 58 | 134 | 1190 | 1.72 |
|Girl, 7 years old, | | | | | |
| Weight 34 lbs. (15.4 kilos) | 40 | 72 | 134 | 1385 | 2.59 |
+--------------------------------+--------+-----+------+--------+--------+
As Professor Jaffa states, the tentative dietary standard for a
woman at light work calls for 90 grams of proteid daily, with a fuel
value of 2500 calories. Both of these women were light in weight,
and furthermore had no occasion to do much physical work; but even
so, a daily consumption of only 0.8 gram and 0.52 gram of proteid,
respectively, per kilo of body-weight, with the small calorific values
indicated, represents a phenomenally small amount of food. And yet
Jaffa, in referring to the woman with the lowest intake of food, states
that even this small quantity of food, judging from the appearance
and manner of the subject, “seemed sufficient for her needs, enabling
her to do her customary housework and take care of her two nieces
and nephew.” Regarding the children, it is stated that the commonly
accepted American dietary standard for a child 13 years old and of an
average activity calls for about 90 grams of proteid and 2450 calories.
As is seen from the table, however, the 13-year-old girl consumed of
proteid less than one-third, and of fuel value only about 60 per cent
of the amount called for; yet, says Jaffa, “notwithstanding the facts
brought out by this comparison, the subject had all the appearances of
a well-fed child in excellent health and spirits.”
We need not consume time in discussing the details of this experimental
study, though the facts are interesting and suggestive, for it is only
the general question of proteid requirement and calorific value that
has interest for us at present. The fact is perfectly clear that this
family of fruitarians, young and old, were quite able to live and
thrive on a diet, the value of which in proteid and calories was at as
low a level as was attained in our experimental studies. The rock of
starvation, however, was not touched or even sighted by the voyagers
down this stream of nutrition. We may all agree that it would be
preferable, as a rule, to acquire the proteids, fats, and carbohydrates
of our diet from a greater variety of sources than did the fruitarians;
we might well complain at a dietary so limited in quality; but the
point to be emphasized is that the low intake of proteid and the low
fuel value were quite adequate for meeting the needs of the body. “It
is a difficult matter,” says Professor Jaffa, “to draw any general
conclusions from the foregoing dietaries without being unjust to
the subjects. It would appear, upon examining the recorded data and
comparing the results with commonly accepted standards, that all the
subjects were decidedly undernourished, even making allowances for
their light weight. But when we consider that the two adults have lived
upon this diet for seven years, and think they are in better health
and capable of more work than they ever were before, we hesitate to
pronounce judgment. The three children, though below the average in
height and weight, had the appearance of health and strength. They ran
and jumped and played all day like ordinary healthy children, and were
said to be unusually free from colds and other complaints common to
childhood.”
Turning now to a larger community,--the island nation of Japan,--whose
exploits in war have recently attracted the attention of the civilized
world, we find a people the great majority of whom have remained
untouched by the prodigality of western civilization, and whose customs
and habits still bear the imprint of simplicity and frugality. After
the restoration of Japan and the reorganization of the government in
1867, much attention was directed to the methods of living and to the
dietary habits of the people, with the result that during the last
twenty-five years there have been slowly accumulating many important
data bearing on the food consumption of the people. These have recently
been brought together in an interesting volume by Kintaro Oshima, and
published[66] in the English language.
[66] A Digest of Japanese Investigations on the Nutrition of Man.
Bulletin No. 159, Office of Experiment Stations, U. S. Department of
Agriculture, 1905.
+-----------------------+--------+--------------------------------+
| | |Digestible Nutrients and Energy |
| | | per Man per Day. |
| Subjects. | Body- +--------+-----+--------+--------+
| |weight. |Proteid.| Fat.| Carbo- | Fuel |
| | | | |hydrate.| Value. |
+-----------------------+--------+--------+-----+--------+--------+
| | kilos | grams |grams| grams |calories|
|School business agent |57.5 | 65.3 |11.3 | 493.8 | 2467 |
|Physician |.... | 61.9 | 8.0 | 468.5 | 2315 |
|Merchant |47.6 | 81.5 |19.6 | 366.2 | 2082 |
|Medical student |49.0 | 74.8 |11.2 | 326.9 | 1811 |
|Medical student |48.5 | 64.7 | 5.1 | 469.6 | 2305 |
|Military cadets |.... | 72.3 |11.7 | 618.1 | 3021 |
|Prisoners without work |47.6[67]| 36.3 | 5.6 | 360.4 | 1726 |
|Prisoners at light work|48.0[67]| 43.1 | 6.2 | 443.9 | 2112 |
|Prisoners at hard work |.... | 56.7 | 7.5 | 610.8 | 2884 |
|Physician |40.2 | 48.3 |15.5 | 438.2 | 2201 |
|Hygienic assistant |40.5 | 46.5 |19.7 | 485.3 | 2430 |
|Medical student |51.0 | 42.8 |14.0 | 438.2 | 2163 |
|Police prisoners |.... | 42.7 | 8.7 | 387.3 | 1896 |
|Army surgeon |54.0 | 79.3 |11.7 | 502.0 | 2567 |
|Soldier |66.7 | 75.8 |13.5 | 563.8 | 2828 |
|Soldier |61.0 | 58.8 |11.3 | 467.8 | 2330 |
|Soldier |56.7 | 55.2 |10.9 | 459.6 | 2276 |
+-----------------------+--------+--------+-----+--------+--------+
[67] Average weight of twenty subjects.
As is well known, the great majority of the people of Japan live
mainly on a vegetable diet. It is also known to physiologists at least
that Japanese dietaries are characterized by a relatively small amount
of proteid, though since the passage of the Food Supply Act of the navy
in 1884, the proteid-content of the navy ration has been decidedly
increased. It will be interesting to note a few of the results collated
by Oshima, and some of the conclusions that he draws from the data
presented. The foregoing table shows a few of the more striking results
of the dietary studies obtained with various classes of people, where
the food used was largely vegetable, but generally with some admixture
of fish or meat.
The figures presented, which represent the actual amounts of food
consumed, with proper correction for the indigestible portion, show
a much smaller intake of proteid than is common with European and
American people; indeed, both proteid and fuel value are very much
less than common practices call for among western peoples, even when
due allowance is made for differences in body-weight. To quote from
Oshima, “Probably the most interesting of the dietary studies are
those with poorer classes, which comprise by far the larger part of
the population. The dietaries of the miscellaneous class, including
employees, prisoners, etc., consisted largely of vegetable foods
and supplied on an average 59 grams of proteid and 2190 calories of
energy per man per day.” Especially suggestive were the results of
a study made with a military colonist, a type of man very common in
Japan; in reality farmers who live at home, but have military drill at
certain fixed times. The subject was carefully selected under advice
of officers in charge of the district, and weighed 59.9 kilograms. His
diet consisted solely of cereals and vegetables, being identical with
that of the people in the rural districts of Japan. His daily food was
found to be composed of 46.3 grams of digestible proteid, with a fuel
value of 2703 calories.
Even more striking were the results obtained in a study of the dietary
habits of three healthy natives of Formosa, employed as day laborers
at the military hospital. They weighed respectively 60.9, 55, and 54.8
kilograms. The main portion of their diet was rice, supplemented,
however, by a little salt fish, salted melon, spinach, ginger, and
greens. The daily amount of proteid ingested was 48.0 grams (37.4 grams
of digestible proteid), with a total fuel value of 1948 calories. A
composite sample of urine covering seven days showed an average daily
output of metabolized nitrogen of 6.93 grams, corresponding to a
breaking down of 43.3 grams of proteid.
Especially interesting also is a series of experiments with
professional men, reported by Oshima, in which attention was paid to
nitrogen balance. The following table shows the essential results:
+--------+-------+----------+-----------------------------------------+
| | | | Digestible Nutrients and Energy |
| | | | per Man per Day. |
|Subject.| Body- |Character +--------+-----+--------+--------+--------+
| |weight.| of Food. |Proteid.| Fat.| Carbo- | Fuel |Nitrogen|
| | | | | |hydrate.| Value. |Balance.|
+--------+-------+----------+--------+-----+--------+--------+--------+
| | kilos | | grams |grams| grams |calories| |
| N. K. | 43.1 |mixed diet| 72.7 |18.3 | 380.7 | 2091 | + |
| S. A. | 49.5 |mixed diet| 69.8 |20.2 | 410.7 | 2222 | + |
| N. K. | 42.9 |mixed diet| 64.4 | 8.5 | 396.3 | 2028 | + |
| N. K. | 43.2 |mixed diet| 62.8 | 8.7 | 433.2 | 2178 | + |
| N. K. | 43.0 |vegetable | 68.5 |19.7 | 433.0 | 2303 | + |
| N. K. | 43.9 |vegetable | 36.8 | 6.6 | 381.0 | 1824 | - |
| N. K. | 42.4 |vegetable | 40.5 | 8.7 | 462.6 | 2200 | + |
| S. A. | 49.6 |vegetable | 34.4 | 7.5 | 451.9 | 2119 | - |
| S. A. | 49.9 |vegetable | 43.5 | 9.1 | 500.0 | 2376 | + |
+--------+-------+----------+--------+-----+--------+--------+--------+
It is to be observed that in all of the above experiments, excepting
two, the subjects gained nitrogen even with the low proteid intake and
the small fuel value of the day’s food. Particularly noteworthy, in
harmony with previous statements, are the results of the sixth and
seventh experiments. In the sixth experiment, the subject was not able
to maintain nitrogen equilibrium on a diet containing 36.8 grams of
digestible proteid and having a fuel value of 1825 calories, but by
raising the intake of carbohydrate food (seventh experiment) to 462
grams daily, thereby increasing the fuel value of the daily ration
to 2200 calories (with a slight increase in the proteid incidental
thereto), the body was able to change its previous loss of nitrogen
into a gain; in other words, the added carbohydrate served as a
protector of proteid.
The series of experiments as a whole, however, is to be considered
in the light of additional data bearing on the dietary customs of a
people who for generations have apparently lived and thrived on a daily
ration noticeably low in its content of proteid, as well as low in its
calorific value. As Oshima states, “It is probably fair to infer that
the amount of proteid in the dietaries of the classes living largely on
vegetable foods (and they constitute the larger part of the population)
may not be very far from 60 grams per day,” or 45 grams of digestible
proteid. It is reasonable to assume that the people live in this way
from force of habit or of necessity, and we may agree with Baelz, a
professor connected with the medical faculty of Tokyo University, “that
their diet is sufficient from a physiological standpoint.” Doubtless a
mixed diet, with a larger proportion of animal food, did their means
readily permit, would offer some advantages from the standpoint of
palatability and variety, but it is questionable if any material gain
in health or strength would result. “It is sometimes remarked,” says
Oshima, “that the peasants in the rural districts of Japan, living
largely on vegetable food, are really healthier and stronger than
people of the better classes, who live on a mixed diet, and the better
physical condition of the former is commonly believed to be due to
their diet.” This, however, is a difficult matter to decide, since
there are so many other factors that are liable to play a part, such as
the general conditions of life which are so widely different in the two
classes.
It is plainly evident that the daily diet of the great bulk of the
Japanese people has been characterized by a very low proteid standard,
as contrasted with the standards and usages of the majority of
European and American people. The fact is brought forward merely as
confirmatory evidence, on a large scale, of the perfect safety of
lowering the consumption of proteid food to somewhere near the level of
the physiological requirements of the body. Generations of low proteid
feeding, with the temperance and simplicity in dietary matters thereby
implied, have certainly not stood in the way of phenomenal development
and advancement when the gateway was opened for the ingress of modern
ideas from western civilization. Many changes are sure to follow in
the footsteps of the nation’s progress, and among these it is safe to
prophesy that as public and private wealth, and resources in general,
increase, the dietary of the people will gradually assume a more varied
character with corresponding increase in volume. Whether such a change
will prove of real benefit to the race, time alone can determine.
Having said so much concerning the Japanese, it is proper that a few
additional statements should be made. The stature and general physique
of the people could be advantageously improved. Is this a question of
dietary, or is it connected with some condition of life on which the
daily food has no bearing; or is it, perchance, a racial characteristic
so deeply ingrained that conditions of environment are without
noticeable influence? These questions cannot be definitely answered
at present. Finally, we may call attention to the dietary changes
inaugurated in recent years in connection with the new organization of
the imperial army and navy. With a view to increasing the efficiency of
the men, following the customs of other countries, an act was passed
increasing the amount of proteid food in the navy dietary. Oshima’s
report of the various steps taken to accomplish this end, with the
results that followed, is interesting in several ways.
“A large part of the rice was to be replaced by bread, and meats were
to be used liberally. The experience, during the first year that
this ration was tried, indicated that bread and meat could not be
advantageously substituted immediately for the rice, because most of
the marines were unaccustomed to these food materials; consequently,
a modification of the ration was introduced in 1885, whereby a
rice-barley mixture was adopted in place of the bread. Barley was
considered at that time as a better article of food than rice, on
account of its higher proteid content, but later investigations showed
that the digestibility of the nutrients of barley was small. In 1886,
an effort was again made to substitute bread for the rice-barley
mixture. In 1890, the ration allowance was reduced by one-fifth and
an amount of money equivalent to the cost of the reduction in diet
was given to each marine with which to buy accessory food according
to his own choice. In 1898, the reduction was made one-tenth, instead
of one-fifth as in previous years. In 1900, the cash allowance was
abolished and a new ration adopted.” This ration contains about 150
grams of proteid (animal and vegetable food) and has a fuel value of
over 3000 calories. In all of these changes, the proportion of rice was
greatly reduced.
Probably, one of the chief reasons why persistent efforts were made
to improve the dietary of the navy was the prevalence among the men
of the disease known as beriberi. “While no satisfactory explanation
as to the cause of the disease was offered, it was generally believed
that there was some very close relation between the disease and the
rice diet” (Oshima). During the years 1878–1883 inclusive, nearly 33
per cent of the marines suffered from beriberi. With the adoption of
the new ration in 1884, in which a large part of the rice was replaced
by bread and other articles, and with better hygienic conditions,
this disease immediately began to disappear, and during the six years
after the adoption of the new diet only 16 per cent of the marines
were affected by the disease. Later on, hardly more than two or three
cases a year were recorded. Advocates of a high proteid diet bring
forward this illustration as an evidence of the danger connected with
a lowered proteid intake; _i. e._, that the nutrition of the body
will be impaired and diseases of various sorts liable to follow. Yet,
Oshima is very careful to state, “It should be especially noted that
here no attempt has been made to indicate the cause of beriberi or the
relation between the disease and the diet.” That rice in itself can be
a cause of the disease is not to be considered for a moment. Further,
so far as any facts are concerned, the writer can see no ground for
considering that a low rate of proteid metabolism has in itself any
direct connection with the disease. From a dietary standpoint, it seems
far more plausible to assume that the great restriction in variety of
foods, so strikingly manifest in the dietary of the poorer people of
Japan, results in a lack of some one or more elements which conduces to
the disease, just as in scurvy the lack of _fresh_ vegetables on long
voyages was liable to be followed by an epidemic of this disease.
Consider the natural character of the dietary of the great bulk
of the Japanese people, determined as it was by adverse financial
circumstances. As Oshima states, “The rural population of the
interior depends very largely or entirely upon a vegetable diet.
Fish is eaten perhaps once or twice a month, and meat once or twice
a year, if at all. The poorer working classes in the cities also
use very little animal food. But the poorer classes in the city and
the peasantry of the rural districts comprise nearly 75 per cent of
the total population, and it is therefore safe to assume that this
proportion lives chiefly, or wholly, upon vegetable diet. And this,
it may be observed, means vegetarianism literally. The so-called
lacto-vegetarianism is unknown in Japan. Cows are scarce, and milk
and other dairy products are expensive, and such as are available are
consumed almost entirely by the wealthier people in the cities.” It is
also to be noted that the amount of fat in Japanese dietaries is very
small. The reported data indicate that the usual vegetable dietaries
contain only about 10 grams of fat per day, while even in the average
mixed dietaries the amount rarely rises above 20 grams per day. In
other words, the ordinary food of the Japanese was characterized by
great lack of variety, and with such a preponderance of carbohydrate
materials of a limited kind that it is easy to conceive of a possible
dearth of some essential or accessory element, necessary for the
preservation of that nutritive balance which aids in protection against
disease.
If the resistance of the body to disease germs and toxic influences in
general is really diminished by reducing the consumption of proteid
food below the set dietary standards, then obviously here lies a
tangible reason for the maintenance of a high proteid intake. I know
of only one series of scientific observations that bears directly on
this question. Dr. Reid Hunt of Washington has studied recently the
power of resistance to the poison acetonitrile of animals kept for some
time upon a reduced proteid diet. “My experiments,” says Dr. Hunt,
“showed in all cases that the resistance was much increased.” In other
words, the animals that had been fed a low proteid ration were able to
endure a much larger dose of the poison than corresponding animals on
their customary diet; “they resisted 2–3 times the ordinary fatal dose
of acetonitrile.” This general subject, however, is obviously a very
important one, and merits further experimental study under a diversity
of conditions.
In conclusion, the facts here presented bearing on food requirements,
especially those that relate to the need for proteid food, are
seemingly harmonious in indicating that the physiological necessities
of the body are fully met by a much more temperate use of food than is
commonly practised. Dietary standards based on the habits and usages
of prosperous communities are not in accord with the data furnished
by exact physiological experimentation. Nitrogen equilibrium can be
maintained on quantities of proteid food fully fifty per cent less
than the every-day habits of mankind imply to be necessary, and this
without increasing unduly the consumption of non-nitrogenous food. A
daily metabolism of proteid matter equal to an exchange of 0.10–0.12
gram of nitrogen per kilogram of body-weight is quite adequate for
physiological needs, provided a sufficient amount of non-nitrogenous
foods--fats and carbohydrates--is taken to meet the energy requirements
of the body.
The long-continued experiments on many individuals, representing
different types and degrees of activity, all agree in indicating that
equilibrium can be maintained indefinitely on these smaller quantities
of food, and that health and strength can be equally well preserved,
to say nothing of possible improvement. The lifelong experience of
individuals and of communities affords sufficient corroborative
evidence that there is perfect safety in a closer adherence to
physiological needs in the nutrition of the body, and that these needs,
so far as proteid food is concerned, are in harmony with the theory
of an endogenous metabolism, or true tissue metabolism, in which the
necessary proteid exchange is exceedingly limited in quantity. There
are many suggestions of improvement in bodily health, of greater
efficiency in working power, and of greater freedom from disease, in
a system of dietetics which aims to meet the physiological needs of
the body without undue waste of energy and unnecessary drain upon the
functions of digestion, absorption, excretion, and metabolism in
general; a system which recognizes that the smooth running of man’s
bodily machinery calls for the exercise of reason and intelligence, and
is not to be intrusted solely to the dictates of blind instinct or to
the leadings of a capricious appetite.