BEVERAGES
Beverages are used primarily to relieve thirst; they may also contain
food elements; they may be used for their effect in heat and cold,
for their flavor, which helps to increase the appetite, or for their
stimulating properties.
They are used to aid digestion and the elimination of waste, to promote
sweating, to soothe inflamed air passages or digestive membranes. They
furnish extra nutrition, stimulate nerve action, quench thirst in
fevers, warm the body when it is cold or cool it when it is hot. They
are used in health or disease, from the snows of the arctics to the
palms of the tropics. They may be alkaline or acid, mineral, medicated
or mucilaginous, effervescing or plain. The question of their utility
and preparation is important in any discussion of foods and food
products, though in themselves they are not foods.
The people of all races seemingly crave a stimulant, after bodily or
mental exertion, in fatigue, as a “bracer” in prolonged effort, as
a promoter of sociability, or as an offering of hospitality. These
stimulants are either alcoholic or non-alcoholic.
It is a notable fact that no tribe is so remote that it does not
possess some form of beverage which may be offered to friends or used
to promote feelings of conviviality; or it may be used to stir up rage
if onslaughts against neighboring tribes are contemplated. The craving
is universal and as old as the race.
Those who decry this craving when it takes the form of alcohol are
often themselves addicted to excessive drinking of non-alcoholic
stimulants.
* * * * *
[Sidenote: Tea]
Tea is not a food—it is a stimulant. It is made by steeping the leaves
of a shrub, called Thea, which grows in the tropical regions of Asia
and adjacent islands.
Green tea differs from black in the mode of its preparation. In green
tea the leaves are steamed before they are dried.
The amount of tannin in green tea is greater than in black, hence green
tea is regarded as not so wholesome a drink as black tea.
The young tender leaves are more delicate of flavor.
Varieties of plants differ both in the amount of tannin and the
delicacy of flavor.
Tea should never be boiled or allowed to stand longer than a few
minutes; standing causes the tannin to be extracted from the leaves,
and this tannin disturbs digestion. It is the tannin extracted from the
bark of trees which toughens animal skins into leather.
The best way to make tea is to pour on boiling water and serve within
five minutes.
Because of the uncertainty as to the length of time tea may be allowed
to steep in hotel kitchens or restaurants, it is a wise custom to have
a ball of tea and a pot of hot water served that the guest may make the
tea at the table.
Tea is diuretic, stimulating the action of the kidneys. Through its
stimulant action it relieves fatigue and has been found especially
useful in Arctic explorations and for soldiers on long marches.
When taken hot it will often relieve sick headache. When taken on an
empty stomach, after a long fatiguing tramp or a prolonged “shopping”
excursion, its refreshing effect may be felt for an hour or two.
The ease of its preparation and the quickness of its effect tends to
produce the “tea habit.” When drunk to excess with meals, it causes
the precipitation of the ferments in the digestive juices, retards
digestion, and may cause constipation, particularly if taken after long
infusion.
Strong tea has an overstimulating effect on the nervous system which
reacts, producing depression and restlessness; this may lead to
insomnia, muscular twitchings, and palpitation of the heart.
Habitual users often take from ten to twenty cups of strong tea daily;
in these the evil effects of the tea habit are easily noted.
Americans, or any people whose nerves are highly stimulated, from the
stress of life, or from habitual nerve tension, should particularly
avoid all stimulating beverages.
Poor tea, because of the greater amount of tannin it contains, produces
its ill effects more quickly. From overstimulation of the nervous
system, poor tea, long stewed, has been held to be a contributing
factor in insanity.
Tea should be avoided by the dyspeptic, by those of constipated and
flatulent habit, or by the anemic.
Tannin coagulates the albumin in milk or cream and the addition of
these to tea renders it more indigestible; plain or with lemon juice
it may be well borne by those with whom it disagrees when used with
cream or sugar.
_Thein_, the active principle in tea, is chemically identical with
caffein in coffee.
* * * * *
[Sidenote: Coffee]
Coffee is prepared from the seeds of the coffee tree. The best known
brands come from the Island of Java, Mocha, Rio de Janeiro, and Mexico.
Coffee, like tea, _is not a food_, it is a stimulant.
The active principle is caffein. This is an alkaloid and is a strong
stimulant to the central nervous system. It quickens the heart action,
and the stimulating effect is so apparent with many, that they cannot
sleep for several hours after drinking it. Others drink coffee to
quicken mental activity and to keep them awake.
It must be borne in mind, however, that there is a reactionary effect
from all stimulants, and while coffee is not intoxicating, as alcohol,
it has a similar effect on the nerves and heart.
Coffee has the redeeming feature of having a pleasing aroma, which,
because of the effect on the mind, may incite the flow of gastric
juice. Despite the fact that no morning beverage has quite the same
pleasing aroma, or pungency, ordinarily one is much better without it.
Coffee stimulates the action of the heart and for this reason it is
used in collapse to restore heart action.
It removes the sense of fatigue and is thus beneficial in some cases,
as in the army, when long marches are necessary.
It is valuable as an antidote in opium poisoning or in cases of
alcoholism.
It is given to those addicted to liquor, as a milder stimulant when
they are recovering from a spell of intoxication.
The only use of coffee as a food is that its pleasant aroma stimulates
the flow of gastric juice.
Strong coffee, particularly that which has been boiled for a long time,
retards digestion, and, if much is drunk, it will produce the same
symptoms of over stimulation of the nervous system as are manifest in
the tea habit. Heartburn, constipation, dyspepsia, and insomnia may
result.
Sometimes the habit is manifested by excessive eating of the coffee
bean. Such users show marked symptoms of nervousness; they are usually
thin and their faces are drawn and anxious.
Each person must decide for himself whether or not coffee or tea is
injurious to him and cease the habit if he finds it is interfering
with the proper functioning of the system, remembering always that the
purpose of food is to resupply body waste and produce heat and energy.
One who knows that coffee disturbs his digestion, and yet cannot break
himself from the habit of drinking it, should have sympathy for the one
who is addicted to liquor and finds it difficult to break the habit of
depending on this _so-called_ stimulant.
_Cereal Coffee_ has been discussed under the heading “Cereals.”
“Crust” coffee is made by pouring boiling water on “caramelized” bread
or bread deeply toasted, allowing it to stand ten minutes, then pouring
off the liquid, which may be sweetened to taste or mixed with cream or
milk. It is also made by using crusts of bread which have been dried in
the oven without being allowed to brown.
* * * * *
[Sidenote: Cocoa and Chocolate]
_Cocoa and Chocolate_ are prepared from the cocoa bean.
Cocoa is from the shell of the bean and chocolate from the kernel. As
shown by Table VII, they are more nutritious than the other beverages.
Cocoa butter is the fat of the cocoa bean. It has a pleasant odor and
does not easily become rancid. Its nutritive value depends on its fat.
Most of the fat has been removed from the cocoa made for the use of
invalids, hence the nutritive value of this cocoa is lessened. The
milk and sugar used in its preparation constitute the most of its
nourishment; the cocoa simply gives a flavor.
Part of the value of chocolate is in the sugar used with it. If well
prepared it is digested with ease and forms a nutritious article of
diet. The habit of using large amounts of chocolate in candy, or as
a beverage, disorders the system because of the gastric disturbances
produced by the excess of sugar.
When food is not easily obtained, compressed cakes of chocolate may be
carried, as in traveling, for a temporary food supply.
Chocolate, as sugar, in moderation, constitutes a good food for the
growing child.
The active principle in cocoa and chocolate is _theobromin_ and, though
milder, is similar to caffein in its stimulating effect on the nervous
system.
* * * * *
[Sidenote: Lemonade]
_Lemonade_ and other fruit drinks, particularly those made from the
citrus fruits, slake the thirst more quickly than most drinks.
All fruit drinks are diuretic, and, whenever the action of the kidneys
is sluggish, they are especially desirable.
* * * * *
[Sidenote: Effervescing Waters]
These are made by forcing carbon dioxid, under pressure, into the
bottle. As soon as the cork is removed the escape of the gas causes
effervescence. These drinks are of no special advantage, other than
that they slake the thirst, because the amount of salts of various
minerals they contain is usually small.
When taken in excess they cause flatulence and may lead to gastric
disturbances. The indiscriminate habit of young people drinking
effervescing waters at soda fountains should be discouraged.
These waters added to milk render it more easily digested.
* * * * *
[Sidenote: Water]
There is no beverage nor concoction devised by man equal to water. It
is to be deplored that it is not used as freely as Nature demands—from
eight to ten glasses a day.
The value of water as a food and as an aid to digestion is discussed on
page 26.
_CONDIMENTS_
Condiments are not foods. They have no nutrition in themselves, but by
their flavor they stimulate the nerves of taste, rendering the food
more appetizing and help to make the diet more varied.
They are relishes and are to be employed in this manner judiciously,
and not used generally in the diet.
Some strong condiments, as cayenne pepper, are of use in dyspeptic
conditions to stimulate the gastric mucous membrane.
They are of value in the dietary of the invalid whose appetite must
be stimulated and careful variations in flavoring will aid in varying
a diet which otherwise would be monotonous, but the excessive use
of condiments, particularly the various peppers, salt, horseradish,
ginger, vinegar, and spices, as indulged by many, so overstimulates
the gastric and intestinal membranes, as to cause catarrhal disease
and dyspepsia. They tend to weaken digestion by calling for an undue
secretion of digestive juices, which, if prolonged, tires out the
glands.
The use of salts is discussed on pages 34-37.
A reasonable amount of condiments such as pepper, salt, nutmeg, cloves,
allspice, sage, thyme, ginger, mustard, cinnamon, mace, horseradish,
vanilla, dill, etc., may be used as appetizers, because the pleasing
thought of them may incite the flow of gastric juice; but they should
not be used to excess.
The taste is undoubtedly a cultivated one, and should not be encouraged
in children. The child rarely cares for condiments and it is better
that he continue to relish his food in its natural flavor.
If beef tea, which so soon becomes distasteful to the sick, is flavored
with different savory or aromatic substances, as parsley, sage, or
mint, it is taken with greater relish.
_Mustard_, so commonly used with cold ham or other meat and in salad
dressing, is sometimes of benefit in stimulating the appetite, but when
used in large quantities, or continuously, it may irritate the stomach.
This irritant quality may be used to advantage, when it is deemed
necessary, as a counter-irritant on the skin, as in the well-known
mustard plaster. A teaspoonful of mustard to a pint of lukewarm water
is an effectual emetic in cases in which it is necessary or advisable
to empty the stomach.
_Capers_, the flower buds of a bush grown in the East, are put up in
vinegar and used in sauces for mutton.
_Cinnamon_, _nutmeg_, and _cloves_ are useful in flavoring foods; they
take the flat taste from hot water and impart a pleasant spiciness.
Many can take milk when flavored, and the slight amount necessary is in
no way injurious.
_Preserved ginger_ is of value for flavoring cereal foods and gruels
for invalids.
_Vinegar_, used in excess, reduces the alkalinity of the blood and aids
in the destruction of red blood corpuscles. It may thus produce anemia
when used in excess.
The acetic acid contained in _cider vinegar_ aids the softening of the
muscle fiber of meat and thus facilitates its digestion. Because of its
preservative qualities it is used in pickling vegetables and various
kinds of fish.
Vinegars made from grapes or other fruits are wholesome. Flavored
vinegars, as tarragon, from the herb of the same name, are useful as
appetizers.
Vinegars artificially made from commercial acids are sometimes
injurious.
_Tomato Catsup_, _Worcestershire_, and _Tabasco sauces_ are not harmful
if used moderately and with due regard to enhancing not destroying the
flavor of the food with which they are used.
_PRESERVATION OF FOODS_
This subject is of ever-growing importance. The study of the
preservation of foods has added much to the store of human knowledge.
By this means it is possible for those living in districts remote from
the supply, those who cannot afford to buy them fresh, and those who
have no cellars in which to store them, to have vegetables and fruits
at all seasons of the year.
Nutritious foods can be prepared in such small bulk and of such
excellent keeping quality that explorers, whether to the arctics or
the tropics, can be kept in first-class physical condition, enabled to
withstand fatigue, and be removed to long distances from the base of
supplies without great hardship.
The decomposition of food is occasioned by bacterial action. Air
is necessary to the growth of bacteria. If the air is excluded the
ordinary bacteria are prevented from exerting their deleterious action.
Heat, as in canning, prevents the formation of bacterial products.
Cold, in refrigeration, by inhibiting bacterial activity is also an
excellent preservative.
Other methods in use are smoking, salting, drying, sterilizing, various
antiseptics, and the exclusion of the air, as in coating eggs or meat
for transportation to other countries.
Eggs are preserved for a long period by excluding the air, which
otherwise penetrates the shell. A solution of water glass (silicate of
sodium), dry oats or salt are used for this purpose.
All food intended for preservation should be kept in a clean, cool,
dry, dark place.
Drying, cooking, and sealing from the air will preserve some meats and
fruits, while others require such preservatives as sugar, vinegar, and
salt. The preservative in cider vinegar is acetic acid, in wine vinegar
tartaric acid.
All preservatives which are actual foods, such as sugar, salt,
and vinegar, are to be recommended, but the use of antiseptic
preservatives, such as salicylic acid, formaldehyd, boracic acid, alum,
sulphur, and benzoate of soda, all of which have been used by many
canning merchants, is fraught with danger. By the efforts of the United
States Department of Agriculture the use of such preservatives has
been largely done away with by the most reliable packers and canners.
However, unscrupulous dealers may use this means of disguising fruits
and vegetables not in good condition.
There can be no doubt, that, whenever possible, the best method is for
the housewife to preserve her own food by drying, canning, preserving,
and pickling, with fruits and vegetables which she knows are fresh.
This, however, is not always practicable.
Since economy in food lies in obtaining the greatest amount of
nutriment for the least money, the preparation of simple foods in the
home, with care that no more is furnished for consumption than the
system requires, is the truest economy.
More brands of prepared food are not so much needed as purity of
elements in their natural state.
_In the effort to emphasize the importance of pure food in amount and
quality, pure air and pure water must not be overlooked. Much infection
is carried by these two elements._
_POISONING FROM FOOD_
Owing to the careful inspection given to various preparations of
foods and the education of the people on the dangers attending the
eating of underripe, overripe, or fermenting fruits and vegetables, or
decomposing canned meats or other foods, cases of poisoning from food
are not so numerous as formerly.
One still reads, however, of illnesses and even fatalities in those
who have, at some gathering, partaken of potted or canned meats, or
ice-cream made from impure milk.
Imperfect sterilization allows the micro-organisms, everywhere present
in the atmosphere, to multiply and produce their toxins.
Any food contained in a can which shows a suspicious bulging in top
or sides (not a dent caused by handling) should be unhesitatingly
rejected, for fermentation has developed gases, which, in trying to
escape, have caused the bulging. Though the practice is less common
than formerly, some grocers offer these bulging cans for sale at less
prices and they are thus purchased by those who look for bargains in
foods instead of for quality.
Sometimes the foods have not advanced to a stage in which the poisonous
products are manifested; but in the intestinal canal the germs
contained in these foods manufacture toxins which are readily absorbed
and produce the severe disturbances noted in cases of ptomain poisoning.
The liver, which has been styled the “watchdog of the body,” has a
special power to destroy many of the toxins contained in the food
material passing through it, and it is due to this fact that many
deleterious substances, taken with the food, are neutralized and their
poisons rendered harmless to the system. When the liver is disordered,
this important function may be hindered, or cease to be active.
Therefore, the importance may be readily seen of keeping the liver in
a vigorous condition by means of exercises which will send an active
circulation through it and keep the nerves controlling it in perfect
functioning order.
Ptomain poisoning results most often from tainted meat, milk, and fish.
Putrefactive processes may have begun in meat, which is thus rendered
“high,” but if it is thoroughly cooked the poisons may be made inert.
Many enjoy the flavor of such meat. The Eskimos, as is well known, will
cache a seal or other animal against a time when food is less plentiful
and after months, perhaps, will eat it with relish and without harm,
though it cannot be touched by people with less hearty appetites. Old
eggs, eaten as a luxury by the Chinese, and the fermented fish used by
other races are familiar examples of tainted foods.
The sale of “bob” veal, or the flesh of very young calves, has been
prohibited because in many people its ready decomposition causes active
diarrhea.
The process of smoking various meats affects materially only the
outside portion, the inner may furnish a suitable bed for the
development of germs. Great care should be exercised and thorough
inspection made of any meat which is eaten raw, as dried beef, or any
pork product.
Ice-cream, as made in the home, is usually innocuous, but when it is
made in factories, unless care is exercised to keep containers clean
and sterilized, the cream or milk may become infected from careless
handling, either before or after it reaches the factory—particularly
in warm weather. Toxins which cause serious and often fatal poisoning
develop. Many such cases have resulted from the free eating of infected
ice-cream at picnics or other social gatherings.
One should guard against overripe cheese, though cheese of any
kind acts as a poison with some people. Cases of severe intestinal
disturbance may occur in those who are unable to eat certain articles
of food, as strawberries, lobsters, or oysters; these attacks should be
carefully distinguished from cases of true poisoning.
Sometimes, however, particularly in the case of fish or oysters
which have been frozen, unless they are eaten immediately after they
have been thawed, toxins develop which cause severe constitutional
disturbance, particularly of the nervous system. These toxins do not
seem to affect the gastro-intestinal tract so markedly. Infected
shellfish, particularly mussels, have caused death in two hours by
their effect on the nervous system.
Many fish after being smoked are eaten raw, and if the ptomains have
begun to develop, poisoning follows.
Care must be taken in purchasing fish for the table that the flesh is
firm and the odor absolutely without taint.
Meat or fish may become toxic to the system through substances eaten by
the animal or by its own physical condition at the time it is killed.
Fish and oysters, therefore, are not eaten during the spawning season.
Cow’s milk may be made obnoxious by substances on which the cow feeds.
Wild garlic when eaten by the cow imparts a nauseous taste to the milk.
The flesh from diseased animals slaughtered and sold for food has
occasioned violent sickness. Government inspection, however, has
greatly lessened the dangers from this source.
Unripe or overripe vegetables and fruit may occasion severe vomiting
and diarrhea.
Moldy flour contains a substance which may cause poisoning.
Rye may have a parasite fungus called ergot and if flour is made
from rye contaminated with this growth, a form of poisoning called
“ergotism” may result. It takes some time and a prolonged use of the
flour to cause untoward symptoms.
Pellagra, which has been giving the southern states so much trouble,
was thought to be caused by the use of spoiled corn meal. It is now
thought to be due to the disturbed nutrition following too monotonous
and unbalanced a diet. The excessive use of corn-meal breads with their
heating qualities and the irritation of the intestinal canal may be an
accessory factor.
A food which is so universally used as milk should be surrounded with
every safeguard possible by rigid inspection from producer to consumer,
as many infective epidemics have been traced directly to a careless or
infected handler of this product. Tuberculosis and typhoid fever germs,
diphtheria and scarlet fever may all be communicated by this means.
Live typhoid bacilli have been found in acid buttermilk. Infected water
used in washing the cans will infect the milk.
Other poisoning may occur by the tin or lead in the inside of cans
being dissolved off by the acids in fruits or vegetables. This is more
likely to occur when the cans of fruit have been kept for a long time.
Housekeepers, who use tin cans, should not put up more fruit than will
supply the family for the season.
Tomatoes, asparagus, strawberries, and apricots are especially liable
to dissolve the tin from the can.
Food should be emptied from the can as soon as it is opened, as
the action of the air hastens deterioration. No cooked fruit should
be allowed to stand in a tin saucepan or other vessel. It should be
emptied as soon as the cooking process is complete.
When a can of fruit, vegetables, or meat is opened, if the interior of
the can is even partially black, it is safe to reject the contents. The
tin in the food will be absorbed in the intestinal tract and may cause
severe disturbance.
Large canners of fruit and vegetables, of the better quality, are now
coating the inside of the can with an insoluble varnish which prevents
the acids from acting on the tin.
The best canners are exceedingly careful and everything in their
factories is scrupulously clean.
_THE ADULTERATION OF FOOD_
Laws against food adulteration have been enacted, but unscrupulous
manufacturers find ways to evade them. On account of these laws,
however, the practice is less general and manufacturers are beginning
to take pride in putting up goods that pass the strictest inspection.
The people, also, are being aroused, through the efforts of the
pure-food propagandists, to the ill effects of adulterated foods both
on the body and the pocketbook and are increasingly demanding that the
foods they buy shall be pure and wholesome.
To lessen the cost of production, many foods are mixed with various
substances before being marketed in order to increase the profits
of the manufacturer or dealer. The contained substance may not be
deleterious to health, but it may lessen the value of the article as a
food.
Among foods which may be so adulterated are jellies, jams and
marmalades, catsups and pickles of all varieties, baking powder,
butter, spices, coffee, corn-starch, mincemeat, vinegar, syrups, sugar,
honey, lard, and flour.
Various adulterants which are used are: wood alcohol (a poison) in
flavoring extracts; vinegar made from various acids and colored to
imitate cider vinegar; rice flour and wheat flour used in ground
spices; kaolin and coloring matter used in candies; paraffin in gum
drops; glucose artificially flavored as maple syrup; cotton-seed oil
sold as olive oil; starch and sugar in powdered cocoa and in chocolate;
chicory, sugar, and pea meal in ground coffee; artificial coffee beans
made of starch, molasses, and chicory; alum and ammonia in baking
powders; artificial coloring of canned peas, beans, and catsups,
butter, cheese, milk, and cream.
It must be said, in justice, however, that housewives are responsible
for many of these productions. Dealers who would be glad to sell only
pure articles say that “the trade won’t have them.”
Many insist on a highly colored cheese, thinking that the color denotes
greater richness, whereas a little reasoning would show them that
the richest old cheeses are pale in color, the deeper color of the
cheese being due to the addition of coloring matter to the curd. While
the coloring matter is not deleterious, the color is no evidence of
richness.
Highly colored green pickles, beans, and peas, should not be used.
Pickles which are hard and crisp are usually made so by alum.
Brilliant red catsup is in demand, though the pure variety is known by
its darker and not so attractive hue.
High coloring in any canned fruit or vegetable is usually an indication
that dye stuffs have been used to produce it.
Fruit jams which are of nondescript color or pale when pure are colored
artificially because the ordinary purchaser demands a pretty product.
Through the vigilance of the food inspectors of the boards of health,
and because of some vigorous prosecutions, the adulteration of the
people’s food is, however, not so easy and profitable an occupation as
formerly.
The Bulletins of the Department of Agriculture furnish a mine of wealth
in the gaining of knowledge of various foods and their preparation, and
may be had free on application to this Department at Washington.
_HEAT AND ENERGY_
The second use of foods, as mentioned before, is to furnish heat
and energy for the work of the body. Heat and energy are produced
_automatically_ by the action of the heart, the movement of the
lungs in breathing, and by muscular activity through the digestion,
absorption, and assimilation of food elements, and through the activity
in tearing down and eliminating waste. They are produced _consciously_
by muscular activity in exercise.
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 an engine consists of coal, wood, or oil. As these are
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 should exactly
equal 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 passing off in the smoke, while some may
remain in the cinders.
The amount of heat and energy generated by the body equals the amount
of latent energy released by the burning of food material during
oxidation.
The carbohydrates and fats constitute the most of the fuel.
The body cells are constantly surrounded by the lymph which contains
the food material—the protein, the carbohydrate, and the fat.
The lymph carries all of the food elements, therefore the protein, the
fat, and the carbohydrate reach the tissues at the same time. If the
fat and carbohydrate predominate, their excess serves to keep a portion
of the protein away from the cells. The cells can use carbohydrate more
easily than fat, so the surplus amount of carbohydrate is first used to
produce energy. This spares the protein which is held in reserve for
tissue repair, and the fat, being least readily used, is stored.
When the carbohydrates and fats are not supplied, or when the system
fails for any reason to appropriate those eaten to its use, the protein
is used for heat and energy instead of being used for tissue building.
If the demand, either in mental or physical energy, exceeds the daily
supply for long, the body becomes lean.
In order, therefore, to maintain a perfect equilibrium the supply of
protein, carbohydrate, and fat should bear the proper relation, any
excess at one time being equalized at another. If an overhearty meal
is eaten the next should be light.
Fat is harder to burn than the starches and sugars so that they are
acted on first as an economy of effort, and the fat is held in reserve
until the carbohydrates are exhausted.
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_. If cold, one should depend more on the oxygen within
than on extra clothing. So many people put on more clothing to conserve
the body heat and forget to generate more heat by arousing the fires
within. This is like covering a dying fire, instead of turning on the
draught to create more combustion.
The carbon in the body is burned by being brought into contact with
oxygen in the blood through exercise and full breathing, just as a fire
is fanned to flame by bringing oxygen in contact with the fuel, by
means of a draught of air. Keep all air away from a fire and it “dies
out,” it has exhausted the oxygen and no heat is produced; keep all air
from within the body, by cessation of breathing, and it also dies.
A room is heated with difficulty if the air in it does not contain
sufficient oxygen. Just so the body which is not constantly supplied
with pure air generates very little heat. The effect of oxygen in the
creation of heat is practically demonstrated by voluntary, rapid, deep
breathing, completely filling the lungs with air, while out in the
cold. The body will become quickly warmed on the coldest day by this
practice.
Ten to twelve deep breaths in succession “turn on the draught” inside
and create combustion (heat), just as opening the draught to a stove by
causing more air to circulate within it increases combustion or heat.
Remember that heat is the result of combustion—the more rapid the
combustion in the body, caused by oxygen breathed in through the lungs,
the greater the heat.
Just as much heat is created when fat is burned in the body as when it
is burned outside of the body.
The heat from “burning” wood is produced by the union of the oxygen
from the air with hydrogen and carbon, forming carbon dioxid and water.
The light in the burning of wood is caused by the rapid combustion.
Combustion occurs within the body more slowly, hence no light is
produced.
The exact process by which the potential energy latent in food is
converted into heat and energy is not known. It is partly released
during the digestive process, through the chemical action produced when
the elements of the food come into contact with oxygen and with the
digestive juices. This combustion gives to the digestive organs the
necessary warmth to enable them to do effective work. A certain amount
of heat is necessary for the chemical changes, and digestive juices
flow more freely when the body is warm. Heat is necessary, also, to aid
the peristaltic movements of the digestive organs.
It has been estimated that about one-sixth of the heat liberated
evaporates through the skin, the lungs, and 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 prepared, some of the fuel is not utilized. 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. If more food is taken than is
necessary to produce heat and energy, the excess of material is stored
and if the excess continues the bodily machinery may be clogged. The
relief lies in consuming the excess through exercise. More oxygen is
required to put the excess in condition for use, and the extra amount
of oxygen is gained by means of the deep breathing occasioned by
exercise.
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.
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.
As mentioned before, the fuel for the body consists of _fats, starches,
and sugars_, which, in combination with oxygen, create force.
From the foregoing, it follows that the fuel value of any food depends
on the amount of fats, starches, and sugars it contains.
The chemical combination of oxygen with food elements and with the
body tissue is known as _oxidation_. It is this chemical action of
the oxygen on the food and on the tissues which produces heat and
energy, either in muscle, gland, or nerve. This energy, in the muscle,
expresses itself in movement; in the gland, in chemical action, and in
the nervous system, by activity of brain or nerve centers. The nervous
energy is closely allied to electrical force.
Nature provides for a reserve of heat and energy, above the immediate
needs, by storing a supply of heat-producing material which is
utilized whenever the daily supply is insufficient or is lacking. Many
hibernating animals store up sufficient fat in summer to provide heat
for the entire winter. This fat would not last throughout the winter,
however, were the animal active. Many individuals carry sufficient fat
to supply all of their needs for months, even though all fat-building
elements were omitted from the diet.
The fact that more oxygen is required for combustion of fat than of
starches and sugars is important for those who wish to call on the fats
stored within the body for daily heat and energy and thus reduce in
weight.
If sufficient starches, sugars, and fats are not consumed in the body
to supply the daily heat and energy released by exercise, the body
calls on the reserve store in the tissues. If much fat or carbohydrates
are consumed in the daily food this will be oxidized before the fat
stored in the muscular tissue is called on.
The scientific reduction of weight, therefore, lies in the regulation
of the daily consumption of starches, sugars, and fats, and the
oxidation of more of these substances through an increase in the daily
exercise.
Deep breathing of pure air should accompany all exercises to supply
sufficient oxygen for combustion or oxidation.
In warm weather little fat is needed for fuel, and Nature provides
fresh green vegetables to replace the root vegetables of the cold
weather, 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.
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 in the liberation of heat. During exercise,
a large amount of carbohydrates and fats are released by the movements
and oxidized; the liberated heat is carried to all parts of the system
and the temperature is raised.
Food in the alimentary canal causes an activity in the glands of the
digestive organs maintaining their temperature.
Of course, while digestion and muscular activity are at their height,
the body temperature is highest. The temperature, as a rule, decreases
from about six at night until four or five in the morning, when it is
usually at its ebb. This is a point of importance. A degree or two of
increase in temperature, above normal, if recorded about six at night,
is not, in most conditions, considered alarming by the physician.
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.
Diuretic foods and beverages, such as water and fruits (melons, lemons,
oranges, grapefruit, etc.), which increase the activity of the skin and
the kidneys, also tend to lower the body temperature.
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 and the reaction is cooling. 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 by a tepid shower or a tepid sponge. The
tepid water will not create a strong reaction, and it will cause a
decrease in temperature. Thus, for fever patients or on 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, followed by
friction, is desirable. When the vitality is low, so that reaction is
slow or chilly feelings persist, the bath must be tempered and greater
friction used.
The generation of heat is also increased by solid foods that require
more than normal activity on the part of the digestive organs. For
this reason the food given fever patients should be that most easily
digested and should be reduced in quantity. Liquid or semiliquid foods
are best.
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.
Scientists have measured 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 4 degrees Fahrenheit.
The fuel value of any food denotes the total number of calories which
may be derived from a pound of that food if it be completely oxidized
in the body.
C. F. Langworthy gives the fuel value of proteins, fats, and
carbohydrates as follows:
1 pound of protein yields 1860 calories
1 ” ” fats ” 4220 ”
1 ” ” carbohydrates yields 1860 ”
That is, according to fuel value—the capacity of the nutrients for
yielding heat and mechanical power—a pound of the protein of lean meat
or egg albumen just about equals a pound of starch or sugar, and about
two pounds of these would about equal a pound of the fat of meat or of
the body fat.
The calculation has been made, based on experiments, that one who
does no muscular work needs only an amount of food which will produce
2700 calories. One doing light muscular work needs 3000 calories. An
individual doing moderately heavy work should take 3500 calories, while
heavy muscular work takes 4500 calories.
One hundred grams of protein food, however, gives only fifteen per
cent. of the amount of energy required. About 500 grams of carbohydrate
and 50 grams of fat are needed to make up the 3000 calories which must
be furnished by the daily supply of food for one doing light muscular
work.
The brain worker, who is using brain tissue more rapidly than the day
laborer, should have a diet equally as rich in protein, though less fat
and carbohydrates are needed.
It has been estimated that an ordinary man on full diet excretes about
twenty grams (about five-eighths of an ounce) of nitrogen a day. As
protein material contains about sixteen per cent. of nitrogen, such an
individual needs to take about 120 grams of protein a day to supply the
nitrogen needs of the body. Because of its need for protein, the body
does not store it.
A day laborer needs 0.28 of a pound of protein a day with enough fat
and carbohydrate to give a fuel value of 3500 calories. A professional
man requires 0.25 (1/4) of a pound of protein a day. Much more than
this is usually taken. This means from 1/3 to 1/2 a pound of lean meat.
_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
every man and woman should endeavor 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._