FOOD REQUIREMENTS OF THE SYSTEM
As previously stated, the object of foods is:
To supply the needs of the body in building new tissue as in the
growing child.
To repair tissue which the catabolic activity of the body is
constantly tearing down and eliminating; and
To supply heat and energy.
The heat and energy are not alone for muscular activity in exercise
or movement. It must be kept in mind also that the body is a busy
workshop, or chemical laboratory, and heat and energy are needed in the
constant metabolism of tearing down and rebuilding tissue and in the
work of digestion and elimination.
In this chapter, a few points given in the preceding pages are repeated
for emphasis.
The proteins represented in purest form in lean meat build tissue, and
the carbonaceous foods, starches, sugars, and fats, supply the heat and
energy.
An excess of proteins, that is, more than is needed for building and
repair, is also used for heat and energy.
The waste products of the nitrogenous foods are broken down into carbon
dioxid, sulphates, phosphates, and other nitrogenous compounds, and
excreted through the kidneys, skin, and the bile, while the waste
product of carbonaceous foods is largely carbon dioxid and is excreted
mostly through the lungs.
Since the foods richest in protein are the most expensive, those who
wish to keep down the cost of living, should provide, at most, no more
protein than the system requires. Expensive meats may be eliminated and
proteins be supplied by eggs, milk, legumes, and nuts.
The fundamental thing is to decide on the amount of protein—two to four
ounces, nearly a quarter of a pound a day—and then select a dietary
which shall provide this and also supply heat and energy sufficient for
the day.
If the diet is to include meat, a goodly proportion of protein will be
furnished in the lean meat. This will vary greatly with the different
cuts of meat, as shown in Table IV, page 54. If, as often happens, one
does not care for fats, then the starches and sugars must provide the
heat. If much sugar is eaten less starches and fats are needed.
The normally healthy individual is more liable to take too much protein
than too little, even though he abstain from meat.
If the diet is to include meat, it will be of less bulk, because the
protein is more condensed; for the same reason, if it includes animal
products of eggs and milk and a fair proportion of legumes, it will be
less bulky than a vegetable diet. Yet unless vegetables, fruits, and
plenty of water are consumed one must guard against constipation. This
point is important for busy people who eat their meals in a hurry and
proceed at once to active mental work.
Those who engage in physical labor are much more likely to take
a complete rest for a half-hour, or an hour, after eating. The
_thinkers_ seldom rest, at least after a midday meal, and those who
worry seldom relax the mental force during any waking hour; their
brains are as active as those of mental workers.
Every housewife, to intelligently select the daily menus for her
family, needs a thorough knowledge of dietetics. She must understand
the chemistry of food that she may know food values.
The difficulty which confronts the housewife is to provide a meal
suited to the needs, tastes, or idiosyncrasies of the various members
of her household. Peculiarities of taste, unless these peculiarities
have been intelligently acquired, may result in digestive disturbances.
As an illustration: one may cultivate a dislike for meat, milk, or
eggs, as is often the case, and if the proteins for the family is
largely supplied by these, the individual who omits them from the meal,
eats too large a proportion of starches and sugars, and not sufficient
protein—legumes, nuts, etc. If this is long continued the blood becomes
impoverished and anemia is produced.
The relief lies in _cultivating a taste for all foods_.
In active work, more heat is liberated, thus more fat, starches, and
sugar are required for the resupply. As previously stated, if an excess
of starch (glycogen) is stored in the liver, or an excess of fat in the
tissues, this excess is called on to supply the heat and energy when
the fats and carbohydrates daily consumed are not sufficient for the
day’s demands. This is the principle in reduction of flesh.
It is interesting to note that habits of combining foods are, perhaps
unconsciously, based on dietetic principles.
Meats, rich in protein, are served with potatoes or with rice, both of
which are rich in starch.
Bread, containing little fat, is served with butter.
Beans, containing little fat, are cooked with pork.
Starchy foods of all kinds are served with butter or cream.
Macaroni, which is rich in starch, makes a well-balanced food when
served with cheese.
Pork and beans, bread and butter, bread and milk, chicken and rice,
macaroni and cheese, poached eggs on toast, and custards, form balanced
foods.
A knowledge of such combinations is important when one must eat a hasty
luncheon and wishes to supply the demands of the body in the least
time, giving the least thought to the selection; but hasty luncheons,
with the mind concentrated on other things, are to be strongly
condemned.
It has been estimated that the average daily need of the adult is
forty-five ounces of solid food, one-fourth animal and three-fourths
vegetable. Twice as much water as solids should be taken.
The laborer, engaged in heavy muscular activity, needs and can
assimilate more than the sedentary office worker. Those who work but a
few hours a day require less food, as a rule, than those who work long
hours.
Cold weather demands more heat-producing foods; a hot climate, inducing
inactivity of body, diminishes the need for food.
The invalid needs less food than the healthy.
The inhabitant of the frigid zone needs much fat; he who lives in the
tropics but little fat.
The old need less food than the growing youth or the hearty adult.
The poor must often take what he can get while the rich eat to satiety.
Yet all these food needs vary with the individual and with the sex and
activity.
It has been computed that the system needs daily three hundred grains
of nitrogen and four thousand eight hundred grains of carbon. To obtain
this amount of nitrogen if bread alone were eaten it would require
four pounds of bread from the whole wheat. The carbon in this amount
of bread largely exceeds that required. If eaten alone, six pounds of
beef would be necessary to supply the proper amount of carbon, and
twenty-three pounds of eggs. The nitrogen in this amount would far
exceed the requirement.
One pint of milk, 2-1/2 ounces of bread, and six ounces of beef are
about equal in nutritive value.
One can see, therefore, why a diet composed of too great a quantity
of one substance gives an overbalance of one and an underbalance of
another.
Therefore, it is more economical to use some fat and sugar in the diet
and less meat. More vegetables, perhaps, and more fluid should be taken
by many.
Authorities vary in their estimates of the amount of food required by
the individual. It varies with the activity, the season, the age, the
sex, and it varies in the same individual on different days.
Billings estimates that the daily diet of a healthy, hard-working man
should contain: 20 ounces (1-1/4 pounds) of lean meat; 22 ounces, about
1-1/3 pounds or 1-1/3 loaves of baker’s bread; 10 ounces or about 4
medium sized potatoes; and several glasses of fluid. Since the fluid
should be twice the amount of solids, this would mean about 12 glasses.
Others compute that the amount of food weighed dry, needed by the
average person of sedentary habits, is as follows: For breakfast, 8
ounces; for luncheon, 6 ounces; for dinner, 9 ounces, with 48 ounces or
3 glasses of water. These two give extremes.
In active persons from 3 to 3-1/2 ounces (about one-fourth of a pound)
of nitrogenous food will replace the nitrogen lost from the body.
One ounce (1-1/16 of the ordinary brick) of butter a day supplies
the necessary fat, and about 15 to 20 ounces (1 to 1-1/4 pounds) of
carbohydrate are required.
According to Thompson, from two to three pints of urine are excreted
each day; ten ounces of water are lost by the lungs, and eighteen
ounces are evaporated from the skin. This amount, about eighty ounces
or ten glasses, must be replaced daily to maintain the body in its
equilibrium of supply and demand. A part of this is supplied in the
food.
These figures may be altered somewhat according to the individual or
the climate as previously mentioned, but they constitute a fair average.
Dr. W. S. Hall estimates that the average man at light work requires,
each day 106.8 grams of protein[10]
57.97 grams of fat
398.84 grams of carbohydrates
These elements, in proper proportions, may be gained through many food
combinations. He gives the following as an example:
Bread 1 lb.
Lean Meat 1/2 ”
Oysters 1/2 ”
Cocoa 1 oz.
Milk 4 ozs.
Sugar 1 oz.
Butter 1/2 ”
A medium-sized man at out-of-door work, fully oxidizes all waste of the
system and he requires a higher protein diet—125 grams. In such event
he does not require so much starch and sugar. If, on the other hand,
he were to take but 106.8 grams of protein, as above, he would require
more carbohydrates. One working or exercising in the fresh air breathes
more deeply and oxidizes and eliminates more waste, hence he has a
better appetite, which is simply the call of nature for replacing the
waste.
Experiments in the quantity of food actually required for body needs,
made by Prof. R. H. Chittenden, of the Sheffield Scientific School,
Yale University, have established, beyond doubt, the fact that the
average individual consumes very much more food than the system
requires. In fact, most tables of food requirements, in books on
dietetics, are heavy, yet the amount of food required as a result of
Professor Chittenden’s experiments would seem to be too light for a
continuous diet.
Professor Chittenden especially established the fact that the
average person consumes more protein than is necessary to maintain
a nitrogenous balance. It was formerly held that the average daily
metabolism and excretion of nitrogen through the kidneys was sixteen
grams, or proportionate to about one hundred grams of protein or
albuminoid food.
Professor Chittenden’s tests, covering a period of six months, shows
an average daily excretion of 5.86 grams of nitrogen, or a little less
than one-third of that formerly accepted as necessary; 5.86 grams of
nitrogen corresponds to 36.62 grams of protein or albuminoid food.
Professor Chittenden’s experiments concerning the amount of foodstuffs
actually required by three groups of men, one group of United States
soldiers, a group from the Yale College athletic team, and a group of
college professors, all showed that the men retained full strength,
with a higher degree of physical and mental efficiency, when the body
was not supplied with more protein than was liberated by metabolic
activity, and when the quantity of carbonaceous food was regulated to
the actual requirements for body heat and energy.
It may be well to call attention here to the fact that most of the food
elements, called on for work, are not derived from those foods just
consumed or digested, but from those eaten a day or two previous, which
have been assimilated in the muscular tissues.
Dr. W. S. Hall gives the rations for different conditions, as shown in
the following tables:
TABLE XI
RATIONS IN DIFFERENT CONDITIONS
———————————————————————————+—————————+——————+—————————+——————————
| Proteins| | Carbo | Energy
| | Fats |hydrates | in
CONDITIONS +————+————+ +————+————+ Calories
|Low |High| |Low |High|
———————————————————————————+————+————+——————+————+————+——————————
Man at light indoor work | 60 |100 | 60 |390 |450 | 2764
Man at light outdoor work | 60 |100 | 100 |400 |460 | 2940
Man at moderate outdoor | | | | | |
work | 75 |125 | 125 |450 |500 | 3475
Man at hard outdoor work |100 |150 | 150 |500 |550 | 4000
Man at very hard outdoor | | | | |
winter work |125 |180 | 200 |600 |650 | 4592
U. S. Army rations | 64 |106 | 280 |460 |540 | 4896-5032
U. S. Navy rations |... |143 | 292 |557 |... | 5545
Football team (old régime) |... |181 | 292 |557 |... | 5697
College football team (new)|125 |125 | 125 |500 |... | 3675
———————————————————————————+————+————+——————+————+————+——————————
TABLE XII
RATIONS VARIED FOR SEX AND AGE
———————————————————————————+—————————+——————+—————————+——————————
| Proteins| | Carbo- | Energy
VARIATIONS OF | | Fats |hydrates | in
SEX AND AGE +————+————+ +————+————+ Calories
|Low |High| |Low |High|
———————————————————————————+————+————+——————+————+————+——————————
Children, two to six | 36 | 70 | 40 |250 |325 | 1520-1956
Children, six to fifteen | 50 | 75 | 45 |325 |350 | 1923-2123
Women with light exercise | 50 | 80 | 80 |300 |330 | 2272
Women at moderate work | 60 | 92 | 80 |400 |432 | 2720
Aged women | 50 | 80 | 50 |270 |300 | 1870
Aged men | 50 |100 | 400 |300 |350 | 2258
———————————————————————————+————+————+——————+————+————+——————————
The unit of measurement for the calories of energy is the amount of
heat required to raise the temperature of one kilogram of water from
zero to 1° centigrade or 4° Fahrenheit.
In estimating the number of calories of energy given off by the
different foods, Dr. Hall represents
1 gram of carbohydrates as 4.0 calories
1 ” ” fats ” 9.4 ”
1 ” ” proteins ” 4.0 ”
To determine the relative energy which a food represents, it is only
necessary to multiply the number of grams of protein in that food by 4,
the fat by 9.4, and the carbohydrates by 4, and add the results.
Thus according to the food required for the average man at light work
given on page 225:
106.8 grams of proteins × 4 = 427.20 calories of energy
57.97 ” ” fat × 9.4 = 544.94 ” ” ”
398.84 ” ” carbohydrates × 4 = 1595.36 ” ” ”
———————
2567.51 = the calories of
energy required for the average man at light work.
TABLE XIII
The following gives a balanced supply for a day according to the
preceding tabulation:
_Amount of Food_ _Calories_
2 tablespoonfuls fruit with sugar 55
2 eggs 140
1/2 pound lean meat (protein) 243
1 pound bread 1206
1/2 pint soup 307
1 tablespoonful cocoa 135
2 potatoes (average size) 100
1/2 pint of milk 150
2 pats butter (1 cubic inch) 119
2 tablespoonfuls sugar 112
————
2567
Dr. Chittenden’s experiments would indicate that a man leading a very
active life, and above the average in body weight, can maintain his
body in equilibrium indefinitely with a daily intake of thirty-six to
forty grams of protein, or albuminoid food, with a total fuel value of
1600 calories.
In order to bring oneself to as limited a diet as Professor
Chittenden’s men followed, however, it would be necessary to have all
food weighed so as to be sure of the correct proportions; otherwise the
actual needs would not be supplied and the body would suffer.
It is a question whether the men with whom he experimented could have
followed so limited a diet for an indefinite period.
As stated, however, authorities differ on the amount of food required.
Dr. Hall suggests 106 grams of protein
Ranke suggests 100 grams of protein
Hultgren and Landergren suggest 134 grams of protein
Schmidt suggests 105 grams of protein
Forster and Moleschott suggest 130 grams of protein
Atwater suggests 125 grams of protein
A wise provision of Nature enables the body to throw off an excess
of food above its needs without injury, within limitations; but, as
stated, there is no doubt that the average person exceeds these limits,
exhausting the digestive organs and loading the system with more than
it can eliminate; the capacity for mental work becomes restricted, and
the whole system suffers.
* * * * *
[Sidenote: Mixed Diet versus a Vegetarian Diet]
From the fact that only from two to four ounces of nitrogenous food
are required to rebuild daily tissue waste, it is apparent that this
amount can readily be supplied from the vegetable kingdom, since
nuts, legumes, and cereals are rich in proteins; yet there is a
question whether a purely vegetable diet is productive of the highest
physical and mental development. Natives of tropical climates live
on vegetables, fruits, and nuts, and it may be purely accidental, or
be due to climatic or other conditions, that these nations have not
made the greatest progress. Neither have the Eskimos, who live almost
entirely on meat, attained the highest development.
The greatest progress and development, both as nations and as
individuals, have been made by inhabitants of temperate climates, who
have lived on a mixed diet of meat, eggs, milk, grains, vegetables,
fruits, and nuts. They have shown more creative force, which means
reserve strength.
The Eskimo has demonstrated, however, that a diet of meat alone
supplies all physical needs; the meat tissue providing growth and
repair and the fat supplying all of the carbonaceous elements. The
fat, as previously stated, yields more heat than starches and sugars,
and Nature provides this heat for climates in which most warmth is
required. This may be the reason why natives of warm climates have
formed the habit of using vegetables and grains for their heat and
energy rather than meat. It is also the natural reason why man in
temperate climates eats more meat in winter than in summer.
An unperverted, natural instinct will always be found to have a sound
physiological basis. For example, if, by reason of some digestive
disturbance, one has become emaciated, all of the fat having been
consumed, and the cause of the disturbance is removed by an operation
or otherwise, one is seized with an almost insatiable desire for fat,
often eating large chunks of the fat of meat or large quantities of
butter or cream at a meal. When obstructions are removed, Nature makes
immediate effort to readjust her forces.
Those who object to eating meat should study carefully to learn if the
proper proportion of protein is supplied with each day’s rations. The
legumes—peas, beans, nuts, and grains—must be supplied. While the wheat
kernel contains twelve per cent. of protein, the white flour does not
contain as large a percentage and it will be noted by reference to
Tables II and III, that the majority of fruits and vegetables contain
little nitrogenous substance.
Unless the whole of the grain and the legumes form a goodly proportion
of the diet the danger is in consuming too large a bulk of waste and
too much starch in a purely vegetable diet.
In a vegetarian diet, one is liable to eat too freely of cereals; as
a result, the liver becomes clogged and torpid and the stomach and
intestines are deranged and rendered incapable of full digestion and
absorption. The clogged system refuses to assimilate more food.
_It follows, therefore, that, unless one is a thorough student of
dietetics, the mixed diet is by far the safest to follow._
One can better run short of starch or fat in one day’s rations than
to be short of protein, because if the two or four ounces daily
requirement is not provided the tissues are consumed and the blood is
impoverished. It is a rare condition in which a reserve of glycogen
and fat is not stored in the system. On the other hand, an excess of
nitrogenous foods calls for a very active circulation and plenty of
oxygen in the system.
It has been held that the vegetarian has a clearer brain, and, if this
be true, it may be due to the fact that he is not eating too much and
thus his system is not overloaded.
Experience, however, does not prove that he has greater mental,
physical, and moral power and efficiency.
In fasting, likewise, the mental power is at first clear and forceful,
but the reason becomes unbalanced if the fast be too prolonged.
_A complete diet may be selected without animal flesh, but including
animal products of eggs, milk, cream, and butter, together with
vegetables, fruits, cereals, and nuts, yet, if the vegetable diet be
selected, the legumes, the whole of the grains, and nuts, must be
given their share in each day’s rations._
* * * * *
[Sidenote: Diet when Traveling]
Each year sees an increase in the number of travelers. The question of
diet many times is of great importance. For those of abundant means the
question is simplified, oftentimes, by the railway dining-car service,
but for those who from economic reasons must patronize the wayside
railway restaurants or other eating places, the diet question is not so
easily solved.
A carefully planned lunch-box is often an aid to the preservation of
regular habits and a preventative of digestive disturbances, due to a
sudden and radical change of diet.
The inactivity and sedentary habit enforced by a long journey, in which
there is small chance for exercise, generally causes constipation. The
shaking of the boat or train also aids this, as it interrupts normal
peristalsis. The motion of the boat or train often produces nausea and
vomiting and thus deranges the digestive organs.
Greasy or illy prepared food hastily eaten at a lunch counter provokes
various gastric and intestinal ills.
The danger of infected or polluted water complicates the problem,
especially when the sick or infants are involved. Many an attack of
typhoid fever has been traced to the drinking water used during a
vacation trip.
The invention of the vacuum bottle has solved one need of the traveler.
The invention of the electric heater has solved another.
Sterilized and cooled milk may be carried by means of the vacuum
bottle for use with children or the sick, and the portable stove will
enable the boiling and sterilizing of water, when a larger supply is
needed than can be carried in a vacuum bottle. By its means, also,
a hot drink can be prepared for the aged, the invalid, or other
individual, when necessary, as in an emergency.
All fried and greasy food and unripe fruits should be avoided.
One had better lessen the amount of food than suffer the gastric
difficulties occasioned by too much fatty food.
Hard whole wheat crackers with fruit and milk can be had at almost any
eating house. These give a well-balanced meal and are often preferable
to prepared dishes. Fresh fruit, especially the acid fruits, should
form a large part of the diet.
The traveler, on extended journeys, should always provide some of the
easily carried condensed foods, so that if the food obtained by the
way is unpalatable or illy prepared, or in case food is unobtainable,
the needs of the system may be met. Beef meal, whole wheat or oatmeal
crackers, malted milk, chocolate, meat extracts, etc., occupy little
space and may often prove invaluable.
Tablets of soda and also of lime are easily carried and may be used
when soda water or lime water is needed as in nausea or indigestion.
If it is possible, the water drunk while traveling should be boiled.
The bowels must be kept active and fresh fruits and water are the best
aids in accomplishing this.
The remedies recommended for car sickness or seasickness are legion;
what is an aid in one case is almost or quite without avail in
another. Lemon juice or a slice of lemon in the mouth is generally of
most avail, though lime water in some cases has proven of service.
Attacks can often be mitigated or avoided by not starting on a journey
when overtired, by light eating for several days previous to beginning
a journey, with care in securing good elimination and plenty of fresh
air.
If traveling by boat a reclining chair on deck is far preferable to
lying in a berth in a stuffy stateroom.
Nausea can often be prevented or remedied by deep breathing or by the
sipping of hot water with a little soda.
FOOTNOTES:
[10] For table of weights see pages 357-359.