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FOODS
Nutrition and Digestion
KNOW THYSELF SERIES
SECOND EDITION
The author, in giving remedial exercises and diet prescribed to suit
the individual need, has for ten years realized the necessity of a
book which shall give to the homemaker a clear idea of the uses of
foods, that she may be able to compile her own diets for various blood
conditions. Since the blood is made from food elements, its conditions
can be largely controlled by a knowledge and regulation of these
elements.
Acknowledgment is here made of the valuable assistance of Winfield S.
Hall, Ph. D., M. D., Professor of Physiology of Northwestern Medical
School, Lecturer and Author of Nutrition and Dietetics; of Alida
Frances Pattee, late instructor of Dietetics Bellevue Training School
for Nurses, Bellevue Hospital, New York City, author of “Practical
Dietetics with reference to Diet in Disease,” and of D. Appleton & Co.,
for their kindness in allowing the use of Dr. Hall’s tables of food
values, in the preparation of this book.
The tables of Food Values and the classifications of foods are kindly
furnished by Dr. Hall and used by the courtesy of his publishers, while
a few of the receipts are generously furnished by Miss Pattee.
Recognition is also made of the good work of Miss Helen Hammel, former
dietitian in Wesley Hospital, Chicago, in the preparation of some of
the receipts in the Appendix.
FOODS
Nutrition and Digestion
BY
SUSANNA COCROFT
AUTHOR OF
GROWTH IN SILENCE
SELF SUFFICIENCY
THE VITAL ORGANS
HABITS: THE NERVES
POISE AND SYMMETRY OF FIGURE
CHARACTER AS EXPRESSED IN THE BODY
IDEALS AND PRIVILEGES OF WOMAN
ETC., ETC.
ORIGINATOR OF THE
PHYSICAL CULTURE EXTENSION SOCIETY
FIRST EDITION 1906
SECOND EDITION 1912
PUBLISHED BY THE
PHYSICAL CULTURE EXTENSION SOCIETY
624 S. MICHIGAN AVE., CHICAGO, ILL.
COPYRIGHT, 1906-1912
BY SUSANNA COCROFT
FOODS
Nutrition and Digestion
BY
SUSANNA COCROFT
The problem of proper nutrition for the body is as vital as any study
affecting the morals, health, and consequent power of a nation,
since upon the quality and quantity of food assimilated, depend the
sustenance, health, and strength of its citizens.
The study of life is the most vital interest in nature. The human race
spends more time in providing nourishment for the body than in any
other line of activity. Next to nourishment comes self-preservation. It
is intuitive, the infant’s first instinct is the preservation of life;
almost at once he seeks for nourishment. His body is ever an awakening
wonder to him. He begins his education by a study of his hands, his
legs, and his flesh.
“The physical satisfactions of life, the joys of mental development,
the inspiration of soul, the sense of growth, of expansion, and of
largest happiness, the self-satisfaction of greatest usefulness, and
the glorifying results of this usefulness, come in largest measure
only to the person whose nutriment is proper in quantity, quality,
and form and is taken properly, as to time, mastication, swallowing,
and digestion, with sufficient exercise to give the body activity to
convert it into use. This enjoyment of vibrant life is far beyond the
joys of the intemperate or the æsthetic.” That ones energies of thought
may not be constantly engaged in deciding what is best, it is important
that proper _habits_ be formed. Habit calls for no conscious energy.
Scientific research along the lines of electricity, psychology,
metaphysics, medicine, and art has been tenaciously pursued for
centuries; yet scientific study of the natural means of keeping the
body in health, that the individual may be in physical, mental, and
moral condition to enjoy and to profit by researches made in other
lines, has been neglected. The result is, that man does not enjoy life
to the full, nor make his physical nor mental efforts yield the best
returns.
It is necessary to know the comparative values of foods as nutrient
agents, in order to maintain our bodies in health and strength, and
with economy of digestive effort, as well as efficiency. The entire
body,—bone, muscle, blood, brain, nerve, heat and energy,—is formed
from the food and drink taken into the stomach and from the oxygen
breathed into the lungs; the mental and physical activity also depends
upon the food. There is no study, therefore, more important than that
of bodily nutrition and the preparation of food and drink in right
proportions to yield the best returns under varying conditions,—age,
employment, health, and sickness.
Nutrition is a broad subject. It means not only that the foods be
supplied which contain elements required to rebuild body substance and
to create heat and energy, but it embraces, also, the ability of the
body to appropriate the foods to its needs. The study of nutrition in
its full sense, therefore, must embrace foods, anatomy and physiology
(particularly of the digestive system), and chemistry, in order to
know the changes foods must undergo in being converted into tissue,
heat and energy[1]. This study, reduced to a science, is known as
Dietetics. There is no more important study for public schools, or for
woman’s clubs.
Nutrition must be solved largely through chemistry. The health and
efficiency of the individual and of the Nation depend upon careful
study of the chemical components of foods and the control of the foods
placed upon the market. The “pound of cure” in the study of materia
medica has been given much thought,—the “ounce of prevention,” little.
The former custom of employing a physician as a retainer had its
distinct advantage, his duty being to instruct in right living so as to
_avoid_ disease rather than to _cure_ it. To-day scientific instruction
in food and hygiene is within the reach of all, and every mother and
teacher is a retainer, or guard of the health of those in her charge.
Happily, the United States Government, realizing that its power as
a nation depends upon the strength and health of its citizens, has
established experimental and analytical food departments. As a result
of the findings of the governmental chemists, there was enacted in
1906, the Food and Drug Act, which aims to raise the standard of
food purity, by prescribing the conditions under which foods may be
manufactured and sold. The law compels the maker of artificially
colored or preserved food products to correctly label his goods. The
national law was the instigation of state laws, which have further
helped to insure a supply of pure food products.
Every particle of body substance is constantly changing. The new
material for cells and tissues, the substance to supply the energy
needed in the metabolic work of tearing down and rebuilding, the energy
used in the digestive process of converting the food into condition
to be assimilated, and the energy used in muscular, brain, and nerve
movement, must all be supplied by food. Every brain effort in the
process of thinking, every motion, and every muscular movement requires
energy which the food must supply.
Brain workers, or habitual worriers, use up force and become thin quite
as quickly as those whose work is muscular. The term “brain workers”
is commonly applied to professional men or women,—to authors, editors,
teachers, or to those engaged in business, but the woman who manages
her household judiciously, or the woman who spends her life fretting
over existing conditions, or worrying over things which never happen,
uses quite as much brain force. The difference is that the former
accomplish results outside of themselves, while the latter simply stirs
up disagreeable conditions within, resulting in physical ills.
_The whole problem of perfect health and efficient activity is in
keeping the supply assimilated food equal to the demand, in keeping
a forceful circulation that the nourishment may freely reach all
tissues and the waste be eliminated, and in full breathing habits
that sufficient oxygen be supplied to put the waste in condition for
elimination._
The body is certainly a marvelous machine! It is self-building,
self-repairing, and, to a degree, self-regulating.
It appropriates to its use foodstuffs for growth and for repair.
It eliminates its waste.
It supplies the energy for rebuilding, and eliminating this waste.
It directs its own emotions.
It supplies the energy for these emotions.
It discriminates in the selection of food and casts out refuse and food
not needed.
It forms brain cells and creates mental force with which to control the
organism.
It keeps in repair the nerves, which are the telegraph wires connecting
the brain with all parts of the body.
It converts the potential energy in the food into heat with which to
keep itself warm.
Withal it is not left free to do its work automatically. It has within
it a higher intelligence, a spiritual force, which may definitely
hamper its workings by getting a wrong control of the telegraph wires,
thus interfering with the digestion, the heart action, the lungs and
all metabolic changes. The right exercise of this higher intelligence,
in turn, depends upon the condition of the body, because when the
mechanism of the body is out of repair it hampers mental and spiritual
control. Surely man is marvelously made!
The intelligent care of the body,—the temple through which the soul
communicates with material conditions,—is a Christian duty. “The
priest with liver trouble and the parishioner with indigestion, do not
evidence that skilled Christian living so essential to the higher life.”
Certain it is that improper foods affect the disposition, retard the
spiritual growth and change the drift of one’s life and of the lives
about one.
Man has become so engrossed and hedged about with the complex demands
of social, civic, and domestic life, all of which call for undue energy
and annoyance and lead him into careless or extravagant habits of
eating and living, that he forgets to apply the intelligence which he
puts into his business to the care of the machine which does the work.
Yet the simple laws of nature in the care of the body, are plainer and
easier to follow than the complex habits which he forms. The “simple
life” embraces the habits of eating as well as the habits of doing and
of thinking.
FOOTNOTES:
[1] It is impossible in this book to go into the anatomy and physiology
of digestion exhaustively.—The reader is respectfully referred to Miss
Cocroft’s book upon “The Vital Organs: their Use and Abuse.” This
traces the food through the digestive canal, indicating the juices
which act upon it, putting it into a necessary state to be absorbed by
the body and appropriated to its various uses.
PURPOSES OF FOOD
The purposes of food are:
To supply the material of which the body is made.
To rebuild tissue, which is constantly being torn down and eliminated.
To produce heat, and to supply muscular and mental energy.
Let us discuss these purposes in above order.
[Sidenote: Food Supply]
By food supply is meant not only that the proper foods in kind and
quantity be eaten, but that the body be in condition to digest, absorb,
and assimilate the foods, and to eliminate the waste, otherwise the
foods fail to supply the body needs. It is the nourishment which the
body assimilates and appropriates to its needs which counts in food
economy.
Of the fifteen to twenty substances contained in foods and comprising
the body, the most abundant are oxygen, hydrogen, carbon, nitrogen,
chlorin, sodium, potassium, magnesium, iron, calcium, phosphorus, and
sulphur. All living matter, plant or animal, contains oxygen, hydrogen,
carbon and nitrogen; the difference in the form and use of the matter
is in the proportions of these elements.
Carbon combined with oxygen forms carbon dioxid. Hydrogen, nitrogen,
and carbon dioxid form the air. Oxygen and hydrogen form water.
Calcium, iron, magnesium, sodium, and potassium form the majority of
rocks.
The substances contained in living organisms are the same as those in
inorganic matter, only in different complexities as appropriated to
each need. This difference in complexity of combinations of the same
elements in a body is the physical difference between a living and a
non-living plant or animal.
By far the most important change which the food must undergo to convert
it from raw material into a state for conversion into body needs is
the chemical change. While the body needs carbon, it cannot use coal;
it needs nitrogen, yet it cannot appropriate it to rebuilding bone
and muscle until, by chemical action with other elements within, it
has been converted into complex substances called proteins; again, the
chemical action of oxygen breaks down the proteins.
The muscles, ligaments, and labor-performing structures contain the
largest amount of proteins; the fats and the carbohydrates contain
the largest amount of carbonaceous compounds; the brain, the nerves,
and the bones contain the largest portion of phosphorous compounds;
yet, while the brain contains phosphorus, and the muscles nitrogen,
the brain cannot be built up by eating elementary phosphorus, nor the
muscles by pure nitrogen, but compounds rich in phosphorus or nitrogen
may be utilized. It has been demonstrated by scientific investigation
that no unorganized element is assimilated by the system and converted
into its various structures.
The gluten of wheat is built up by the chemical union of nitrogen in
the air and nitrogen in the soil with other substances. Plants are able
to use the simple compounds of the earth, air, and soil, and, within
their own cells, build them up into such complex substances as starch,
sugar, protein, fat, and salt, which are appropriated by the animal
kingdom for further growth and change.
In its conversion into tissue, heat, energy, and waste, the importance
of the chemical exceeds the mechanical action, such as digestion,
absorption, assimilation, and elimination; yet the chemical changes are
aided by the mechanical.
Each individual should know, approximately, the chemical constituents
and the proportion of these constituents in normal blood, because from
the elements in the blood, the tissues are constructed. If certain
elements be lacking, the foods containing these elements in largest
proportions should be supplied until the blood no longer shows the
deficiency. This is Nature’s method of correction.
Each meal, or each day’s food, may not contain just the amounts of
protein or of fuel ingredients necessary for that day’s work and
re-supply, but the body is continually storing material, and this
reserve is constantly being drawn upon to provide any element which may
be lacking in that day’s supply. Thus, an excess or a deficiency one
day may be adjusted the next. Healthful nourishment requires that the
balance, as a whole, be kept, and that a deficiency or over-supply be
not continued for too long.
Many domestic animals take their food elements from air and water, as
well as from the compounds which the plants have formed; while others
make use of meat, a compound formed by another animal. The digestive
forces of the animal has converted these elements into flesh, a
compound easily assimilated by another.
The greater part of the muscles, nerves, and glands of the animal
kingdom is _protein_. The skeleton is composed largely of deposited
salts, while the elements which supply heat and keep up muscular
activity are _starches, fats, and sugars_.
The _proteins_ are appropriated by man from plants, but they are
furnished to him in more easily digested form in lean meat and eggs,
the lower animals having done much of the work of digestion, converting
the proteins from plant life into more condensed form. On the other
hand, by access to this concentrated form of easily digested protein,
man is in danger of taking in too much of this condensed food, if he
eats a large quantity of meat and eggs.
It must be apparent to every thoughtful person, since the nerves,
muscles, and glands are composed largely of protein and the skeleton
largely of salt, that, in order to furnish the body with the elements
necessary for growth and repair, these elements must be provided, as
also the substances producing the energy for the working body. _Each
individual should make a self-study to know how much re-supply is
required to renew the daily waste._
About one-third of the food eaten goes to maintain the life of the body
in doing its incessant work of repairing and rebuilding, the remaining
two-thirds is the reserve for usefulness outside of itself.
One of the most remarkable, and the least understood of any of the
assimilative and absorptive functions, is that any one part of the body
has the power to appropriate from the foods the elements necessary for
its own rebuilding, while these same elements pass through other organs
untouched. The body has the power, also, to not only make use of the
foods, but to use up the blood tissue itself. Just how this is done is
also a mystery.
There is surely a great lesson in industry here, and one of the most
profound studies in economics, physics, and chemistry.
[Sidenote: Heat and Energy]
The second use of foods, as mentioned before, is to create heat and
energy for the work of the body. This includes the action of the heart;
the movement of the lungs in breathing; the digestion, absorption, and
assimilation of food elements; the tearing down and elimination of
waste; and the muscular activity of body movements.
Just as any engine requires fuel, water, and air to create the force
necessary to run the machinery, so does the human engine require fuel,
air, and water. The fuel for the engine consists of coal, wood, or oil.
As these are rapidly brought in combination with oxygen, combustion,
or oxidation, takes place, liberating heat and setting the engine in
motion. The amount of energy or force given off by an engine exactly
equals the amount of latent energy provided in the fuel. Much of this
energy is commercially lost, since much of the latent force in fuel is
not fully liberated, some, not liberated, going off in the smoke, while
some may remain in the cinders.
Just so in the body,—the amount of heat and energy given off from the
body exactly equals the amount of latent energy released by material
burned during oxidation. It is estimated that about one-sixth of the
heat liberated evaporates through the skin, the lungs, and through the
excreta, while five-sixths is required to maintain the body heat.
If the digestive forces are not working perfectly and if the food is
not properly cooked, some of the food is not made perfectly soluble
for absorption. But in normal conditions, if the food is supplied in
proportion to the energy required, the heat and energy given off should
exactly equal the latent heat and energy consumed in food.
It is to be noted, also, that no force within the body is lost. In the
very process of the removal of waste, heat and energy are created, so
that the parts no longer needed are utilized by the system, while they
are being removed from it. Here is a lesson in economy of force.
As mentioned before, the fuel for the body consists of _fats, starches,
and sugar_, which, in combination with oxygen, create force. The
combination of oxygen with other elements in the body is known as
oxidation. This oxidation liberates heat and at the same instant
produces energy, either in muscle, gland or nerve. The muscular energy
expresses itself in muscular motion, the glandular in chemical action,
and the nervous in nervous energy. The nervous energy is closely allied
to electrical force.
The _starches_ come largely from cereals and root vegetables; the
_sugars_ largely from cane, from certain trees, and from vegetables,
fruit, and milk; the _fats_ come from vegetable oils, from animal fat,
as fat, and some from milk and butter. Some fats are also formed from
proteins.
From the above, it follows that the fuel value of food depends upon the
amount of fats, starches, and sugars contained.
The exact process of the conversion of the potential energy latent
in food into heat and energy is not known. It is partly released
during the digestive process, as the elements of the food come into
contact with the oxygen swallowed and with the digestive juices. This
combustion gives to the digestive organs the necessary warmth for their
effective work. Digestive juices will not flow freely when the body is
cold. The heat liberated during the digestive process is necessary,
also, to put the elements of the food into condition for absorption, a
certain amount of heat being required for the chemical changes. This
liberated energy is expressed, not alone in the chemical formation
of the compounds, but in the peristaltic movements of the digestive
organs.
A small portion of the heat of the body is gained from the sun or
from artificial heat, but by far the greater part is generated within
the body. If one is cold, the quickest way to get warm is to generate
more heat within by “turning on the draught”, or, in other words, by
breathing in more oxygen. So many people cover up the body with more
clothing to reserve the body heat and forget to generate more heat by
arousing the fires within. This is like covering up a dying fire to
reserve the heat, instead of turning on the draught to create more
combustion.
Nature provides for a reserve of heat and energy, above the immediate
needs, by storing up a supply which is called into use whenever
the daily supply is inadequate. Many hibernating animals store up
sufficient fat in summer to provide heat for the entire winter. This
fat would not last the winter, however, were the animal active. Many
individuals store up excess of fat sufficient to last them for months,
even though all fat building elements be omitted from the diet.
It must be remembered that anything which creates a greater activity of
the tissues, such as muscular exercise, liberates a greater amount of
heat. The reverse is also true;—a decrease in the amount of muscular
movement means a decrease of heat liberated. During exercise, a large
amount of fat, protein, and dextrose (sugar) are released by the
movements and oxidized; the liberated heat is carried to all parts of
the system and the temperature is raised. Mental work, for the same
reason, tends to raise the body temperature, though to a much less
degree. Food in the alimentary canal causes an activity in the glands
of the digestive organs and also increases the temperature.
Of course, while digestion and mental and muscular activity are at
their height, the body temperature is highest. These activities usually
reach a maximum in the afternoon and the temperature is then highest,
while, as a rule, it decreases from about six at night until four or
five in the morning, when it is usually at its lowest ebb. This is a
point of importance to physicians. Even five degrees above the average
human temperature, if recorded about six at night, is not considered
abnormal.
Anything which causes an increase in heat radiation, as perspiration,
lowers the temperature, and the open pores of the skin are valuable
aids in equalizing the body heat. A person who perspires freely does
not suffer with heat, during excessive exercise, as does one whose
pores are closed.
One ready means of regulating the body heat is the _bath_. If one takes
a hot bath, the temperature is materially raised by the artificial
heat, but there is a recompense in the increase of heat radiation from
the skin. If one takes a cold bath, the immediate effect is cooling,
but the activity set up within, to create a reaction, soon heats the
body to a greater degree than before the bath. The best way to increase
the evaporation and thus decrease the temperature of the body is with
a tepid shower or a tepid sponge. The tepid water is not so extreme
as to create a strong reaction and it will cause a marked decrease in
temperature. Thus, for fever patients or for a warm day, the tepid
shower or sponge is commended; for a cold day, or for the individual
whose circulation is sluggish, the cold bath is desirable. Where the
vitality is low, so that there is not sufficient reaction, the bath
must be tempered.
Heat generation is also increased by solid foods that require more than
normal activity on the part of the glands for digestion. For this
reason the food for fever patients should be that most easily digested
and should be reduced to the minimum to keep up the strength.
Diuretic foods and beverages, which increase the activity of the skin
and the kidneys, also tend to lower the body temperature.
While the elements of the food are being oxidized, the latent
(potential) energy released by the oxygen creates mental and physical
force and keeps active the metabolic changing of food into tissues and
cells, also the changing of cells and tissues into waste.
The young child’s blood circulates freely, his breathing is
unrestricted, the waste of the system is fully burned up, potential
energy is released, and the result is, he must be active. The effort of
the teacher, or of those having the care of children should be, not to
restrain the child, but rather to direct his activity in advantageous
and effective use of his energy.
Scientists have a means of measuring the energy latent in food
material, also the amount of heat given off in the oxidation of a
given quantity of waste. The unit of measurement is the calorie,—the
amount of heat which will raise one pound of water to four degrees
Fahrenheit, or will lift one ton one and fifty-four hundredths.
Truly the body is a busy work-shop. Think of the billions upon billions
of cells being formed and destroyed every instant in the liberation of
heat and force! Think, also, of the necessity of perfect circulation to
bring sufficient blood to the lungs, that it may gather the oxygen and
carry it, without pausing for rest, to every tissue of the body! Even
in sleep this stream continues incessantly.
There is also a great lesson here in the law of supply and demand;—when
the body is at mental or muscular work, the potential energy liberated
leaves through muscle or brain, as energy, and is expressed in
the result of the work; when the body is at rest, it leaves it as
heat (excepting such part as is necessary to carry on metabolism,
circulation, etc.) If much muscular energy is called for, a deep, full
breath is instinctively drawn to supply the oxygen necessary for the
added force required.
If strong mental work is required, attention should be given to
exercise and deep breathing the while, that the blood may carry off
the waste liberated by brain activity. The difficulty is that in
doing close mental work, the body is too frequently bent over a desk
in such a manner as to restrict the action of the lungs; thus, the
brain worker, in order to continue strong, mental work, must often go
into the open air,—as he says, “to rest his brain”, but in reality to
re-supply the oxygen required to carry on his work and to carry away
the waste liberated by brain energy. The supply for the body work has
been called upon for the undue brain work, and this lack of oxygen has
produced a state of body designated as “tired.” Until the necessary
oxygen has been supplied, the brain and body are not balanced, not
“rested.”
_Nothing is lost in Nature’s distribution of force and energy.
Everything accomplished in life, either in the physical handling
of material, the brain work in planning the constructions, the
mental movements of thought in art, literature, or science, are all
representatives of the heat and energy released from the body, and it
is the effort of every man and woman to make the body yield as large an
income as possible in the expression of this energy. In order that it
may do so, it must be used with intelligence, just as any other great
machine must be used intelligently; it must be fed, exercised, and
rested judiciously._
[Sidenote: Repair and Elimination of Waste (Metabolism)]
Every part of the body is constantly changing. Its work never stops. If
kept in thorough repair it must be torn down and rebuilt incessantly.
These chemical changes are called collectively _metabolism_. They
are divided into two groups: the chemical process of building up
complex substances from simple ones is known as _anabolism_; the
chemical process of oxidizing and breaking down the complex substances
into simple ones, so that they are in a state to be excreted, is
_catabolism_. While the process of oxidation in catabolism is going on,
heat and energy are set free. Most of the chemical changes in the body
are catabolic in character. This work of tearing down and rebuilding
body tissues never ceases—even in sleep.
It is not enough that the proper foods be furnished the body in
kind and quantity. The essential thing is that the system be kept
in condition to _assimilate_ the foods to its needs and to promptly
eliminate the waste. Few people assimilate all of the foods eaten;
nearly every one eats more than necessary for the body needs.
By _assimilation_ is meant the digestive process by which foodstuffs
are made soluble and diffusible, so that they can pass into the blood;
also, the metabolic activity by which the food is converted into cells
and tissues.
Nature provides for an incomplete knowledge of the amount of re-supply
necessary, by enabling the system to carry off a limited amount of
surplus food above the bodily requirements.
The distinct steps in anabolism are discussed in the following chapter
describing the work of different organs and the chemical changes of
foods as they come in contact with the elements in the digestive
juices.
CLASSIFICATION OF FOOD ELEMENTS
By _foodstuff_ is meant the chemical elements, appropriated by the
animal for the use of the body, as described above. By _foods_ is meant
those articles of diet found in the market which contain the chemical
elements used by the body in various combinations. Bread, for example,
contains all of the foodstuffs and has been called the staff of life,
because it sustains life. Foods may contain elements, not foodstuffs,
and not used by the body, but cast out as waste, while certain foods,
such as sugar, cornstarch, olive oil, and egg albumen, contain only one
foodstuff, as will be noted in the following classification of foods
and foodstuffs—grouped according to the body uses.
There are many classifications but the following tables, as compiled by
a leading dietitian[2] for his practical work in classes, are clear
and concise.
Carbonaceous foods:
Sugars
Starches
Root and tuberous vegetables
Green vegetables
Fruits
Fats
Nitrogenous foods:
Lean meat
Eggs
Gluten
Carbo-nitrogenous foods:
Cereals
Legumes
Nuts
Milk
The above classifications are made because of the preponderance of
certain elements in them, not because they do not contain other
substances; e.g. vegetables are mixtures of sugars and starches; fruits
are mixtures of sugars, vegetable acids, and salts; milk, legumes,
cereals, and nuts contain a more equal division of sugars, fats and
proteins and are therefore represented as carbo-nitrogenous; lean
meats, with the exception of shell fish, contain no starch, but all
meats contain fat, protein, and water, and all, except liver, contain
ash.
In the table below, examples are given of foodstuffs in which the
chemical elements are almost pure representatives of their classes.
Cornstarch, sago, and tapioca are almost pure starch, containing very
little of any other element; glucose, cane sugar, syrups, and honey are
almost pure sugar; butter, lard, and olive oil are nearly all pure fat;
egg albumen, gluten, and lean meat are almost pure protein.
{ { Water { Corn Starch
{ Inorganic { Salts { Starches { Sago
{ { { Tapioca
{ {
{ { Carbonaceous { { Glucose
{ { (producing { Sugars { Cane Sugar
{ { heat & energy){ { Syrups
Foodstuffs { { { { Honey
{ { {
{ { { { Lard
{ Organic { { Fats { Olive Oil
{ { { Butter
{ {
{ { { Egg Albumen
{ { Nitrogenous—Proteins { Gluten
{ { (growth and { Lean Meat
{ { repair)
The _proteins_ contain nitrogen, sulphur, and phosphates. The
predominance of nitrogen has given the proteins the name nitrogenous.
The carbonaceous foods contain none of these elements, but are rich in
carbon, hence the name carbonaceous.
As previously stated, no food contains but one element of foodstuffs
and all elements are formed into compounds of plant life from the
elements in the soil, air and water by the action of the sun’s rays.
The rays of heat and light seem to store something of their power in
latent heat and energy within the combinations of these compounds.
The end of plant life is the completion of its compounds,—it first
generates the compounds, then matures them, and then dies.
All _organic_ matter is thus formed by the action of the sun’s rays
upon _inorganic_ matter. All meats are first in the form of plant life
and are converted into other compounds by the chemical processes of the
animal. This chemical action of the animal converts the energy latent
in the foods into more concentrated form. The animal thus performs a
part of the chemical work for man.
The classification of foods, as previously stated, is based upon the
principal organic foodstuffs contained. Proteins contain carbon and
salts, and carbonaceous foods contain salts and nitrogen, but these
are not in appreciable quantity. The preponderance of these elements
determines the use of the foodstuffs in the body. It will be remembered
that the chief uses are the production of heat and energy, the building
of new tissue of the growing child, and the repair of the waste in the
child and the adult.
* * * * *
[Sidenote: Water]
No one element of food is more important for the needs of the body
than water. It comprises about two-thirds of the body weight and is a
component part of all foods. It is composed of oxygen and hydrogen.
In order that the body may do efficient work in digestion and in the
distribution of the nutrient elements of the foods, and that the
evaporations from the body may be re-supplied, the water in the foods,
together with the beverages drunk, should consist of about seventy-five
per cent liquid to twenty-five per cent nutrient elements, or about
three times as much in weight as proteins, fats, and carbohydrates
combined. If undue evaporation or perspiration is occasioned, a larger
proportion is required.
Water passes directly into the circulation without chemical change. It
is being constantly evaporated through the lungs and the skin, and
every forty-five seconds it passes from the kidneys into the bladder.
The average individual at normal exercise, requires about seventy-one
and one-half ounces of water daily, which equals about nine glasses
(one glass of water weighs one-half pound); a part of this is consumed
in the food. By reference to the following tables it will be noted
that water forms a large percentage of all food, particularly of green
vegetables and fruits.
The importance of water for children must not be overlooked. It is the
heat regulator of the body, and the more energy used, either in work or
in play, which results in more heat and evaporation, the more water is
required. An animal, if warm, immediately seeks water.
The body will subsist for weeks upon the food stored about its tissues;
it will even consume the tissues themselves, but it would burn itself
up without water, and the thirst after a few days without water almost
drives one insane. It should be furnished freely, in small quantities
at a time, to fever patients.
Few people, give much thought to its re-supply; yet they suffer from
the loss of it, in imperfect digestion and assimilation, and with
kidney and intestinal difficulties, ignorant of the cause.
Water softens and dissolves the food and aids in its absorption;
it is one chief agent in increasing the peristaltic action of both
the stomach and intestines, thus aiding in mixing the food with the
digestive juices and aiding the movement along the alimentary canal;
it increases the flow of saliva and of digestive juices and aids these
juices in reaching every particle of food more promptly; it aids in the
distribution of food materials throughout the body, carrying them in
the blood and the lymph from the digestive organs to the tissues, where
they are assimilated; it forms a large part of blood and lymph.
The theory has long been held that water drinking at meals is
injurious, the objection being that the food is not so thoroughly
masticated if washed down with water, and that it dilutes the digestive
juices. But this theory is not so strongly held as formerly—in fact, it
is now rightly disputed by the best authorities.
_When water drinking at meals is allowed to interfere with mastication
and is used to wash down the food, the objection is well taken_, but
one rarely drinks while food is in the mouth, the water being taken at
rest periods between mouthfuls. _Thorough mastication and a consequent
free mixing of the food with saliva is one of the most essential steps
in digestion_, and the flow of gastric juice, as the flow of saliva, is
stimulated by the water.
If, on the other hand, the food is not thoroughly masticated, water is
most essential to furnish that which the saliva would otherwise supply
to soak up and dissolve the food, in order that the gastric juice may
more readily reach all parts of it.
It is singular that the use of water at meals has long been considered
unwise when the free use of milk, which is about seven-eighths water
has been recommended.
The copious drinking of cool water from a half hour to an hour before
a meal will cleanse the stomach and incite the flow of saliva and
gastric juice. Moreover, the digestive cells secrete their juices more
freely and the sucking villi absorb more readily when the stomach and
intestines are moderately full, either of food or water, and to fill
the stomach with food requires too much digestion. The water passes
through the stomach before the food.
In building up about seven thousand thin women, results show that
the free drinking of liquid at meals has a tendency to put on flesh.
Probably one reason for this is because of the cleanliness and greater
freedom given to the absorbing and secreting cells of the mucous lining
of the digestive tract, as well as to the stronger peristalsis.
_It will be noted that water drinking at meals has many more arguments
in its favor than against it._
One important use to which water is put is to cleanse the digestive
tract and the kidneys. This cleansing within is more necessary than the
cleansing of the surface of the body. One cannot form a better habit
than that of drinking two to three glasses of water upon first arising
and then working the stomach and intestines by a series of exercises
which alternately relax and contract their walls, causing a thorough
cleansing of these organs.
In case of gastritis, or a catarrhal condition of the stomach, often
a pint of slimy mucus will collect in the stomach over night and the
cleansing of the mucous lining of the digestive tract is then most
important.
The drinking of warm (not too hot) or cold water in the morning depends
upon the condition of the individual. If in good condition, two to
three glasses of cold water, the vigorous exercises for the vital
organs, and deep breathing of _pure_ air, followed by a cold bath,
will do more to _keep_ the health, vigor, clear skin, and sparkling
eye than fortunes spent upon seeking new climates, mineral waters, or
tonics. There is no tonic like water, exercise, and fresh air, as above
prescribed.
Soft water, that is water containing no lime or other mineral matter,
is best for cooking purposes; hard water, which causes any degree of
curdling of soap, or a lime crust in the bottom of a tea kettle, is
hard on digestion. Bacterial germs are killed and much of the mineral
matter deposited by boiling the water. For drinking purposes it should
be aerated that it may regain its original, fresh taste, otherwise
boiled water tastes flat or insipid. It may be aerated by filling a jar
half full of water, leaving the other half for air, and then shaking
the water in the jar so that the air passes through it.
Many claim that one’s thirst, as in the desire for food, is the only
safe guide, as to the amount and time of drinking, but these desires
are largely matters of habit, and tastes are often perverted. Unless
the condition is abnormal or the mind becomes so intensely active that
one fails to listen to the call of nature, the system calls for what
_it has been in the habit of receiving_ and at the stated times it has
been in the habit of receiving it. The safe method is to form the habit
of eating and drinking a stipulated amount at regular periods and not
allowing this regular habit to be broken, unless, for some cause, the
system be out of order, and then the habit should only be broken for a
time.
* * * * *
[Sidenote: Salt]
Milk furnishes salt in proper proportion for the baby, and later, when
the child is through nursing, eggs should be added to the diet of cow’s
milk. It is especially essential that growing children be furnished
milk and eggs that they may be assured of the proper proportion and
quantity of calcium salts, as these form the substances of bones and
teeth, which constitute about one-sixth of the body weight.
All vegetables, fruits, cereals, legumes, and nuts furnish both calcium
salts and sodium, potassium, and magnesium, which are the salts used
in the blood and lymph. Minerals are abundant in dried legumes, (beans
and peas). A diet consisting largely of vegetables needs the addition
of sodium chlorid (common table salt) to supply sufficient salts
for foods; likewise more salt than is contained in grass and fodder
is needed for animals, particularly for those producing milk. The
scientific farmer salts his cattle regularly, while wild animals travel
miles and form beaten paths to springs containing salt.
In rectal feeding, it is known that food absorbs more readily through
the large intestine if salted. It is probable that salt, in normal
proportions, also aids absorption in the stomach and small intestine.
Salt should not, however, be used immoderately.
The minerals of the food, or of the body, form the ashes in burning.
* * * * *
[Sidenote: Iron]
Iron is an inorganic substance and is necessary in making red blood
corpuscles.
If, by some disturbance in the digestion, absorption, or assimilation
of food, more iron is excreted from the body than is made use of from
the food, the blood making organs do not receive sufficient iron and
the blood is lacking in red corpuscles. It becomes poor in hemoglobin
and the individual becomes pale. This condition is known as _Anaemia_.
Where there are not sufficient red blood corpuscles, it is of
vital importance that one keep up a good circulation; the stomach,
intestines, liver, and spleen must be strengthened through exercise and
one must breathe deeply of pure air, for the red blood corpuscles are
oxygen carriers, and the insufficient supply must do double duty or the
waste of the system will not be oxidized and eliminated.
A diet rich in iron must be supplied. It will most often be found that
one whose blood is lacking in hemoglobin and in the proper proportion
of red blood corpuscles, has had a dislike for the foods rich in iron,
or, perhaps, has not been able to get the right kind of food.
The yolks of eggs, the red meats (such as steak, mutton or the breast
of wild game), and the deep colored greens, (such as spinach, chard,
dandelions, etc.) contain a goodly proportion of iron. The dark color
of greens and of the dark meats is given to them by the iron which
they contain. The dark leaves of lettuce, celery, and cabbage contain
iron, but these vegetables are apt to be bleached before being put upon
the market.
The yolks of two eggs are better than one whole egg, as the iron is in
the yolk. A good way to take the yolk of eggs is in egg lemonade or in
eggnog, with a little nutmeg for spice.
FOOTNOTES:
[2] Winfield S. Hall, Ph. D., M. D., Prof. of Physiology, Northwestern
University Medical School, Chicago.
Carbonaceous Foodstuffs
The carbonaceous foods are those used by the body for heat and
energy and are so named because they contain a large proportion of
carbon,—heat producing element. It is the carbon in wood, which,
uniting with oxygen, produces heat and light.
The carbonaceous foods are all composed of carbon, hydrogen, and
oxygen, the difference being in the different proportions in which
these elements are combined.
They are divided into two classes, Fats and Carbohydrates. The
carbohydrates embrace the sugars and starches and include such
substances as the starches of vegetables and grains (notably corn,
rice, wheat, and the root vegetables), and the sugar of milk, of
fruits, vegetables, and the sap of trees. Their chief office is to
create energy. They are almost entirely absent from meat and eggs, the
animal having converted them into fats.
Carbohydrates are easily digested.
* * * * *
[Sidenote: Fat]
Fat is the most concentrated form of fuel and is readily oxidized. It
is almost pure carbon, hence less chemical work is required to convert
it into fuel, but more oxygen is needed. A pound of fat has about three
times as much fuel value as a pound of wheat flour, which consists
largely of starch.
Fat forms about fifteen per cent of the weight of the normal body, and
it has about twice the fuel value of carbohydrates.
Carbohydrates and fats are each composed of carbon, hydrogen, and
oxygen, the difference being that there is less oxygen in fat, hence,
more oxygen from the air is required for combustion of fat than for
carbohydrates. One pound of starch requires one and one-fifth pounds of
oxygen for perfect combustion, while one pound of suet requires three
pounds of oxygen. For this reason the Eskimo, who depends largely upon
the fats for body heat and energy, must have plenty of fresh air. One
ounce of fat yields two and one-half times as much energy as an ounce
of sugar or starch.
If sufficient fat is not consumed, or is not formed from the
carbohydrates (starches and sugars), a certain portion of the protein
of the body is converted into fat and used in energy. When the food
supply is short, or much energy is called for, the surplus supply
of carbohydrates is first used, and, if the carbohydrates are not
sufficient, the proteins are used. Of the proteins, the gelatinoids
are used first, and next the albuminoids, or tissue builders. If the
demand, either in mental or physical energy, exceeds the daily supply
for a length of time, the body becomes lean.
In warm weather little fat is needed for fuel and nature provides
fresh, green vegetables to replace the root vegetables of the winter,
which, consisting largely of starches and sugars, are readily converted
into heat. In cold weather, especially in high altitudes or latitudes,
more fuel foods are required to keep the body warm and more fat is
eaten in winter.
Those who store up an abundance of fat suffer most from a rise in
temperature, because combustion not only creates heat, but heat also
aids combustion.
Fats are not digested in the stomach. The connective tissue about
the fat is digested here, and the fat is passed on into the small
intestine, where it is acted upon by the carbonates and by lipase, one
of the enzymes of the intestinal juices. These first change the fat
into an emulsion and then into a form of soap and glycerine. In this
saponified form, it is in condition to be absorbed into the circulation
and carried out to the tissues, where it is assimilated and used in
energy; a similar chemical change is produced in the conversion of oil
into soap.
Common examples of fats are butter, cream, the fat of meats and of
nuts, and the oil of grains and seeds,—notably the cocoanut, olive,
and, of the grains, oatmeal.