What to eat and when

by Susanna Cocroft

ILLUSTRATIONS

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Susanna Cocroft	[Frontispiece]
Diagrammatic Representation of Villus	[146]

What to Eat and When

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CHAPTER I
PURPOSES OF FOOD

The purposes of food are:

To supply the material out of which the body may rebuild the tissues.

To produce heat, and to liberate muscular and mental energy.

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 effort of the brain in the process of thinking, every motion, and every muscular movement requires energy which the food must supply.

The body is composed of a vast number of cells varying according to the tissue or organ in which they are found. The characteristic of all living matter is that it constantly reproduces itself. Cells perform their appointed work, wear out, and must be replaced by new ones or derangements follow.

The new cells constantly being formed, increase in size and in so doing push the worn-out, dying, and dead cells out of the way. The process of building and eliminating continues within the body and on its surface every instant of life.

An idea of the number of dead cells constantly being thrown off from every part of the body may be gained by noticing the amount of dead skin cast off. The fine scales of “scarf” or “dead” skin, which we easily rub off in a friction bath, are composed of these dead cells which have been crowded out by the hosts of vital cells constantly forming beneath. The process is the same in every tissue and organ. The dead or worn-out matter within the body is burned by oxygen and put in condition to be carried by the blood to the organs of elimination, the kidneys, intestines, lungs, and skin.

Much waste is eliminated in liquid form through the sweat glands. It is said that stokers throw off four pounds of water and waste a day through the skin.

In the growing child the process of building and of eliminating is active and rapid. In the youth it is less rapid, in the adult still less, but unless the process is kept active, stagnation and death ensue.

Daily exercise is necessary to keep up the body activities; yet very few take the trouble to secure daily a complete, thorough circulation of blood, especially through the vital organs and the deeper tissues. Perfect circulation is the key-note of health.

Activity of any kind necessitates the expenditure of energy. The process is a chemical one and in all chemical processes heat is necessary to cause the decomposition of elements and their recomposition into different substances.

Heat in its turn has two functions. It enables the chemical changes to be carried on which fit the food for the use of the various tissues, and it burns to an ash the worn-out products of the body’s activity, fitting them for elimination.

It keeps the tissues flexible and the secretions fluid; coagulation takes place when the secretions become cold.

As previously stated, food in the body, then, is needed for two purposes:

(1) to build and maintain the cell until its work is done;

(2) to furnish the heat necessary to decompose the food into its elements, and to produce the energy by which all the body processes are carried on.

Food Elements

That the food may be appropriated by the body it must be not only proper in kind and quantity, but the body must also be in condition to digest, absorb, and assimilate it and to eliminate the waste, otherwise the body needs are not met.

It is the nourishment which the body assimilates and appropriates to its needs which counts in food economy, not necessarily the amount consumed.

Therefore if the food is to economically serve its purpose, the body must be in a condition to digest and assimilate it—this condition depends largely on perfect circulation, correct position of organs, and correct breathing habits.

Of the fifteen to twenty substances contained in foods and comprised in the body, the principal ones are oxygen, hydrogen, carbon, nitrogen, chlorin, sodium, potassium, magnesium, iron, calcium, phosphorus, and sulphur. The differences in the forms of matter lie in the proportions in which these elements are combined.

Those containing the largest proportion of nitrogen are called Nitrogenous foods or Protein—such as meat, eggs, and some vegetables.

Those containing the largest proportion of carbon are known as Carbonaceous—such as cereals, sugar, and fat.

The four food elements, indispensable to life, either of plant or animal, are oxygen, hydrogen, carbon and nitrogen.

Carbon combined with oxygen forms carbon dioxid.

Oxygen, nitrogen, and carbon dioxid largely form the air.

Oxygen and hydrogen form water.

Calcium, iron, magnesium, sodium, and potassium are used in the formation of the various tissues and secretions of the body.

The substances contained in living organisms are the same as those in inorganic matter, only in different complexities as appropriated to the needs of each organism.

The difference between living and non-living matter is in the relative proportion and arrangement of the same elements.

Before it is fit to supply the needs of the body, the raw material must undergo a chemical change.

It has been demonstrated by scientific investigation that no unorganized elements, such as pure nitrogen, pure iron or magnesium, are assimilated by the system and converted into its various structures.

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, it has been converted into complex substances called proteins.

The muscles, ligaments, and labor-performing structures contain the largest amount of nitrogen.

The fat contains the largest amount of carbon.

The brain, the nerves, and the bones contain the largest proportion of phosphorus compounds.

Yet, while the brain contains phosphorus, and the tissues 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.

Plants 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 salts, putting them in condition for man and other animals to appropriate to their use.

All plant life is compounded from the elements in the soil, air, and water, by the action of the sun’s rays. The rays of heat and light store something of their power in latent heat and energy in these plant compounds.

The end of plant life is the completion of its compounds—when it has matured them, the plant dies.

All organic matter is thus formed by the action of the sun’s rays on inorganic matter.

The gluten of wheat is formed from the chemical union of nitrogen in the air and nitrogen in the soil with other substances.

The starch of wheat and other grains is from carbon which the plant has taken from the soil and combined with other substances.

All meats are largely derived from plants which have appropriated the elements from the soil, water, and air. The chemical processes of the animal convert the energy latent in the plant foods into the more concentrated form of meat. The animal thus performs a part of the chemical work for man—the digestive organs of one animal convert the food contained in certain plants, into a substance more easily assimilated by another animal.

Man would need to eat a large amount of nitrogen-containing plants in order to get as much protein as is contained in one egg or in a piece of lean meat the size of an egg. It is because the nitrogen is in such condensed form in meat and eggs that one is likely to take more than the system can handle, if he eats too freely of these two foods, particularly of meat. We will discuss this question more fully under “Proteins.”

Most domestic animals take their food elements from air and water, as well as from the compounds which the plants have formed, while wild animals and some domestic ones, such as hogs and chickens, make use of meat as well.

The greater part of muscle, nerve, and gland is composed of protein.

When the muscles are exercised constantly they use up their protein and must have it resupplied, or the muscle substance will waste. When the muscles are exercised freely, as in the laborer, or the athlete, they need more building material.

The skeleton is composed largely of deposited salts, as calcium. If, therefore, the growing child be not supplied with a sufficient amount of this substance, the bones will be weak and liable to deformity and the teeth will be slow in coming or will be small and malformed. Children need foods rich in lime.

The elements which supply heat and keep up muscular activity are starches, fats, and sugars.

It must be apparent to every thoughtful person, that, since the nerves, muscles, and glands are composed largely of protein and the skeleton largely of calcium salts, in order to furnish the body with the elements necessary for growth and repair, all of these elements, as also the energy-producing substances, must be provided.

Each individual, therefore, should learn how much he requires to replace his daily waste, both for rebuilding tissue and for supplying heat and energy.

The day laborer, though he may do more muscular work than an athlete in training, expends scarcely any nervous energy. Therefore he needs less protein in his diet than one does who expends both nervous and muscular activity, as does the athlete.

CHAPTER II
CLASSIFICATION OF FOOD ELEMENTS

By foodstuffs are meant the chemical elements appropriated by the animal for the use of the body, as previously described.

By foods are 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. This refers to bread made from the whole of the grain. White bread, as commonly eaten, is not the “staff of life.”

Foods may contain elements, not foodstuffs, and not used by the body, but cast out as waste. Certain foods, such as sugar, corn-starch, olive oil, and egg albumin, contain only one foodstuff, as will be noted in the following classification, in which the foodstuffs are grouped according to the body uses.

The classification of foods is based on the principal organic foodstuffs they contain. The preponderance of the elements in any one food determines its chief use in the body.

It will be remembered that the chief uses of foods are to produce heat and energy, to build the tissue of the growing child, and to repair the tissues in the child and the adult.

Nearly all foods are made up of a combination of substances.

The following tabulations give the classification of foods based on their predominating elements.

Nitrogenous foods:

Lean meat
Eggs
Gluten

Carbonaceous foods:

Sugars
Starches
Root and tuberous vegetables
Green vegetables
Fruits
Fats

Carbo-nitrogenous foods:

Cereals
Legumes
Nuts
Milk

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 shellfish, contain no starch, but all meats contain protein, fat, and water.

Foodstuffs		Inorganic		Water		Starches		Corn-Starch
				Salts				Sago
								Tapioca
				Carbonaceous		Sugars		Glucose
				(producing				Cane Sugar
				heat & energy)				Syrups
								Honey
						Fats		Lard
		Organic						Olive Oil
								Butter
						Proteins		Egg Albumin
				Nitrogenous				Gluten
				(for growth				Lean Meat
				and repair)

In the above tabulation, examples are given of foodstuffs which are almost pure representatives of their classes.

Corn-starch, sago, and tapioca are practically 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 albumin, gluten of flour, and lean meat are almost pure protein.

As previously stated, however, no food contains but one element of foodstuffs.

NITROGENOUS FOODSTUFFS OR PROTEINS

Protein is a complex combination consisting of seventeen elements. The digestive organs split up protein into these seventeen substances, and they enter the blood thus split. When they reach the tissues, each tissue selects the elements it needs and recombines them according to its own peculiar functional uses.

Meat and eggs contain the complete protein.

Protein exists in all vegetables, but few vegetables contain protein which is made up of the whole seventeen substances, hence more vegetable food has to be eaten to secure the protein in the quantity and combination necessary to maintain life.

Of these seventeen elements the predominating ones are nitrogen, sulphur, and phosphates. The predominance of nitrogen has given the proteins the name nitrogenous.

Proteins are the tissue builders.

In this connection it may be well to state that blood is a tissue; thus meat and eggs build the blood, as well as muscle and sinew.

All nitrogenous foods contain considerable carbon—mostly in the form of fat in the meat elements—but the carbonaceous foods contain so little protein that the protein elements do not appreciably enter into the nutrition.

Carbon and nitrogen in the carbo-nitrogenous foods are about equal in proportion.

The nitrogenous or protein elements in the body constitute about one-fifth of its weight. They form the basis of blood, lymph, muscle, sinew, bone, skin, cartilage, and other tissues.

Worn-out body tissue is constantly being torn down and eliminated and the protein in the foods must daily furnish material for repair, as well as for building new tissue.

A young animal’s first need is for growth, as it has not learned to exercise sufficiently to use much latent energy. The first food it receives is an animal product—milk to babes and other mammals—while the young chicken or bird is nourished by the yolk of the egg contained within it. Sufficient yolk substance remains within the chick when it is hatched to sustain its life for the first day or two.

Nitrogenous foods are more concentrated and contain less waste; thus a smaller bulk is required than of vegetables and fruits. According to recent experiments, the average adult requires from two to four ounces of nitrogenous foods a day, to repair the waste. Happily, when more is consumed, the system has the power up to a certain limit (depending on the physical condition and the daily activity), to eliminate an excess.

It is needless to say that if the daily waste is not replaced, digestion and nutrition suffer. The system must have the two to four ounces necessary to supply the nitrogen daily excreted, or the tissues themselves will be consumed.

The proteins, of which meat is the principal member, are classified as:

Albuminoids: albumin (white of eggs), casein (curd of milk), myosin (the basis of lean meat and gluten of wheat);

Gelatinoids: (connective tissue of meat);

Extractives: (appetizing and flavoring elements).

If protein material is taken into the body in excess of its needs the excess is used as fuel. While vastly more expensive, an excess of protein is worth no more as fuel than starch is; 1 gram of protein produces 4.1 calories of heat, no more than 1 gram of starch.

The proteins produce heat and energy when the supply of sugars, starches, and fats is exhausted, but proteins alone form muscle and the larger part of blood and sinew. They are, in this sense, the most important of foods; they are also the most costly.

An excess of protein, usually eaten in the daily intake of food, then, is of no practical use and can be eliminated with great benefit to the pocketbook. Meat once a day is sufficient. The excessive consumption of meat can be lessened with no lack of nutrition to the body. The trouble is that meat is the first thing thought of for a meal; it is easily prepared and housewives are not willing to use the thought and effort necessary to secure a balanced meal without it.

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—the 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 between them being in the different proportions in which these elements are combined.

They are divided into two classes, Carbohydrates and Fats.

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Carbohydrates

The carbohydrates embrace the sugars and starches and include such substance 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.

The starches are converted into sugar, so they are together given the one name of carbohydrate. The name means that carbon and hydrogen are contained in them in such a proportion that when oxygen unites with the hydrogen, water is produced and the carbon is liberated. In this chemical process heat is produced. One gram of carbohydrate produces 4.1 calories of heat.

They are almost entirely absent from meat and eggs, the animal having converted them into fats.

When the digestive organs are in a normal condition carbohydrates are easily digested.[2] They do not play a large part in the growth of the body tissues, but they are utilized by the body to spare the consumption of the fat which is stored in the tissues as a reserve. This explains their action in preserving but not producing fat. When there is an excess of fat and the desire is to reduce, the carbohydrates should be limited that the body may call on the reserve fat for heat and energy.

Few realize that after the starches and fats have been consumed in heat and energy the tissues are consumed.

The assimilation of the carbohydrates is almost complete, so that the energy derived from them may be closely calculated.

SUGAR

There are many varieties of sugar. Those commonly used as foods are, cane sugar (sucrose), fruit sugar (levulose), sugar of milk (lactose), sugar of malt (maltose), sugar of grapes or corn (glucose), maple sugar, honey, and saccharin—a coal-tar product. They are derived from plants, from trees, and from tubers or other vegetables.

Cane sugar (sucrose) is derived from the juice of the sugar cane and from beets. One-third of the world’s supply of sugar is derived from the sugar cane and two-thirds from beets. From two to ten per cent. of sucrose may be obtained from the maple tree. It is also found in the sugar pea.

All sugars are carbohydrates—carbon, hydrogen, and oxygen—the oxygen and hydrogen being in the proportions which form water (two atoms of hydrogen and one of oxygen).

Brown sugar is granulated sugar in an early stage of refinement.

Maple sugar is obtained by boiling down the sap of the maple tree. It is often adulterated with other sugars or with glucose from corn, because they are cheaper. This adulteration does not make it unwholesome, but causes it to lose its distinct maple taste.

The nutritive value of sugar is said to be about ninety-five per cent.

Glucose was formerly derived almost entirely from grapes. Later the process was discovered by which the starch in corn was converted into glucose. It is produced so much more cheaply from corn that this is now the chief source of supply.

Glucose is also found in most of the fruits, in combination with other sugars. It needs little change to be absorbed by the system and quickly overloads the digestive apparatus if much of it is eaten.

It is pure, wholesome, and cheap, and for this reason it is often combined with other sugars. It is not so sweet as cane sugar, though just as nutritious. Many of the syrups on the market are made from it.

Candy is often made from glucose instead of from molasses or cane sugar.

Much candy, unless one is actively exercising, tends to produce indigestion.

While glucose is wholesome, it ferments readily.

Before sugar can be used by the system, it is changed into the easily absorbed form of the sugar in grapes, by a ferment in the small intestine. Hence digested sugar in the body is called grape sugar.

Milk sugar needs less chemical change than other sugars and is taken almost at once into the circulation. It is contained in the natural food for the infant.

The digested sugar (grape sugar) is further changed in the body into glycogen. When an excess of sugar or starch is consumed, it is stored within the body as glycogen, until required.

Sugar is perhaps a better food than starch, because less force is required for its digestion and it is easily assimilated, being more readily converted into dextrose than are starches.[3] Moreover it furnishes the heat and energy needed by those having small power to digest starch.

Sugar is soon oxidized, and, for this reason may be eaten by those who need to use an extra amount of muscular strength, or to get strength quickly. It yields heat and energy within thirty minutes after eating, and in times of great exertion or exhausting labor, the rapidity with which it is assimilated gives it advantage over starch. Because it is so quickly converted into energy it is valuable for children at active play.

Experiments with soldiers on forced marches, and in Arctic explorations, have shown the value of sugar as a food, in enabling the men to withstand hunger, thirst, and fatigue. Taken in excess, however, particularly by those of sedentary habits, it clogs the system as does any other excess of material, creating difficulties for the liver and kidneys.

During muscular activity, four times as much sugar is consumed in the body as is ordinarily used in the body processes.

Used in limited quantities, therefore, according to the muscular or brain power exercised, sugar is one of the best foods for the production of energy.

When much sugar is eaten the starches and fats in the food should be lessened to avoid overloading the system.

When eaten in excess, sugar may temporarily appear in the urine unaltered.

It might be inferred that, as all starch must be converted to sugar before it can be used by the body, starches might be discarded and replaced by sugars. A small quantity of sugar, however, soon surfeits the appetite, and if the foods were confined to those having a surplus of sugars, sufficient food would not be eaten to supply other needs of the body. This lack of appetite occasioned by an excess of sugar is due, partly, to the fact that the gastric juice is not secreted so freely when there is much sugar in the stomach.

Because of the slower secretion of gastric juice and the surfeit of the appetite occasioned by them, sweetened foods should not be used at the beginning of a meal, and, while a moderate amount of sugar is desirable, a surfeit will cause indigestion. This is particularly liable when one eats sufficient starch and sugar at a meal and then eats candy between meals.

Sugar is so readily oxidized and supplies heat and energy so promptly, that the fats stored in the tissues are not called on until the latent energy in the sugar is used. The power of sugar to fatten thus lies in sparing the use of body fat; when starch and fat are used in addition to sugar an excess of fat quickly results. Therefore, those who wish to reduce in flesh should eat sparingly of sugar that the starches and fats may be used to furnish energy, but sugar should be as freely used as the system can handle it, by those who wish to build up in flesh.

Broadly speaking, about one-fourth of a pound of sugar, daily, in connection with other foods, is well utilized by the system, the quantity depending on whether one leads an active or a sedentary life.

The natural flavor of fruits and grains is very largely destroyed by sugar, which is used too freely on many articles of diet. Sugar should never be added to fruits while cooking, if intended for immediate use, as the acids of the fruits neutralize a portion of the sugar. More sugar is thus used than is needed after the cooking process is completed.

The sweet taste in all fruits and vegetables is due to the presence of sugar. Sweet potatoes, beets, carrots, parsnips, turnips, grapes, figs, and dates are especially rich in sugar, and when these are furnished with a meal, in any appreciable quantity, the starches should be restricted—notably bread, Irish potatoes, and rice.

Those who do hard work in the open air, because of the increased oxidation, can consume larger quantities of sugar in pie or other pastry, which ordinarily would be difficult to digest. One who lives an indoor life should refrain from an undue indulgence in such foods.

For one who is undernourished, sugar is a desirable food, if the starch be diminished in proportion as the amount of sugar is increased; but the tendency in sweetening foods is to take more starch also than the system requires, since it is the carbohydrate foods which are ordinarily sweetened—not the proteins.

On account of their latent heat and energy, sugars are more desirable in cold weather than in warm. For this reason Nature supplies them more abundantly in the root vegetables, eaten more freely in cold weather. More puddings and heavier desserts may be eaten in cold weather.

The desire of the child for sweets is a natural one, because the child uses much energy, and sugar supplies this energy with less tax of the digestive system. When the child begins to eat more solid foods, if sugar is used in abundance for sweetening, he is no longer attracted by the mild sweetness of fresh milk, and it is well not to sweeten cereals or other foods, also to limit other sweets, when the child turns against milk, in order to restore the taste for this valuable food. Many authorities state that a child, up to its third year, should not be allowed to taste artificial sweets, in order that the appetite may not be perverted from the natural sweets of milk.

Sugar is better supplied the child in a lump or in home-made molasses candy, rather than in the sweetening of porridge, oatmeal, or bread and milk, etc.

Molasses is readily absorbed and is mildly laxative, and when young children are not allowed to eat too much, it assists in keeping the bowels open.

Sweet fruits, fully ripened, contain much sugar and should be freely given to the child.

Starch

Starch is one of the most important carbohydrates. It is formed from the carbon dioxid and water in the air and in the soil by the chemical action of the sun’s rays on the cells of living plants.

As stated, corn-starch, sago, tapioca, and arrowroot are practically pure starch. Rice is almost pure starch.

Corn-starch is obtained from young maturing corn; tapioca comes from a tropical plant, cassava; sago from the pith of the sago palm; arrowroot from a plant of the same name, a native of the West Indies.

Starch lacks flavor and for this reason all starchy foods are seasoned with salt. Salt increases the activity of the saliva and pancreatic juices.

All starches must undergo much chemical change by action of the saliva and the intestinal juices, before they can be used by the body.

The digestion is begun by the saliva in the mouth and is continued in the stomach, by the saliva, until the gastric secretions begin to act.

Starch is not acted on by the gastric juice but passes unchanged into the intestines, where it is converted, by the pancreatic juice, into dextrin, maltose, and glucose. It is thus absorbed into the blood.

After the digested starch passes into the blood it is taken to the liver and is there changed into glycogen and is stored in reserve. When the system needs to produce energy it is first furnished by the glycogen. When this is exhausted the fats and proteins are used.

The starches and sugars then are really the energy “reserves” of the body, any excess over the daily needs being stored until required.

Starchy foods should not be given to any one in whom, from disease or derangement, the starch-converting ferments, ptyalin in the saliva and pancreatin in the pancreatic juice, are lacking.

Because the child has not developed the ferment in sufficient quantities necessary for starch digestion, starchy food must not be given to a child under twelve to eighteen months; at least not until he has teeth and chews his food. Then he should be given starchy food in the form of a crust or hard cracker which he chews thoroughly and mixes with saliva.

Potatoes or bananas which the child does not masticate, should not be given him under the age of two years.

Fat

Fat is the most concentrated form of fuel and is readily oxidized. It has about twice the fuel value of carbohydrates. It is almost pure carbon, hence less chemical work is required to convert it into fuel, but more oxygen is needed.

The average fat person does not breathe deeply and does not take in sufficient oxygen to cause a combustion of the fat and produce energy. He is thus inclined to be lethargic.

A pound of fat has about three times as much fuel value as a pound of wheat flour, which consists largely of starch.

Common examples of fat are butter, cream, the fat of meat and of nuts, and the oil of grains and seeds—notably the cocoanut, olive, and oatmeal.

Fat forms about twenty per cent. of the weight of the normal body.

The body cannot remain in health for long unless a proper amount of fatty food is eaten. Muscular and nerve action, and the formation of the digestive secretions are all dependent on the energy derived from the combustion of fat. Its use in this way spares the tissues from destruction in the chemical processes necessary to life.

Both carbohydrates and fats are composed of carbon, hydrogen, and oxygen, the difference being that there is less oxygen in fat. 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. One ounce of fat yields two and one-half times as much energy as an ounce of sugar or starch.

Fats are not digested in the stomach. The connective tissue about the fat is dissolved here, and the fat is passed on into the small intestine, where it is acted on by the bile and the intestinal juices. These first change the fat into an emulsion and then into the form of soap and glycerin. In this saponified form, it is in condition to be absorbed and carried to the tissues, where it is assimilated and used in energy. The commercial production of soap from oil is similar to the chemical change in the body of fat into soap.

The supply of fat stored in the body depends on the quantity consumed with the food, on the quantity used up in heat and energy in muscular or mental exercise. The quantity assimilated depends somewhat on the condition of the nerves. If the nerves are weak, they do not strongly direct digestion and assimilation and less fat is used in the digestive and assimilative processes; thus, in case of weak nerves more fat is often stored in the tissues. An excess of fat often indicates sluggish nerve activity.

Manual laborers require more fat for energy than do people whose habits are sedentary. School-children, or children who play hard, should have sufficient fat and sugar.

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Butter and Cream. The fat present in milk, depends of course, on the quality of the milk. There is as much butter-fat in a glass of fresh Jersey milk as in a glass of cream from the milk of some cows. The cream from some Jersey cows is eighty per cent. butter-fat.

Skimmed milk contains very little fat. If milk is drunk by the adult, as a means of storing up more fat within the body, the cream, if assimilated, should be stirred into it.

The Fat of Meat. This should be thoroughly cooked. All meats in the process of baking or frying should be covered, in order to retain the moisture. The fat in well-roasted beef is nutritious, but to make fat easily digestible it should be well masticated so as to break up the tissue fibers which surround it.

While fried foods are difficult of digestion (see page [192]) because the surface albumin is coagulated and the hot fat forms a coating around it, making it difficult for the digestive juices to reach the tissue, the fat of bacon is more easily dissolved because of the delicacy of the fibers surrounding the fat cells. If thinly sliced and fully immersed in its own grease in the process of frying, bacon is an easily digested fat. The process of smoking the bacon renders it easier of digestion.

Cooked bone-marrow is an easily digested form of fat which is usually relished by those to whom any other fat is repulsive. It is useful in some forms of anemia, as it contains considerable iron.

Eels, salmon, and mackerel contain much fat.

The Eskimos extensively use both whale and seal oil as a food.

The yolks of eggs are also rich in fat.

Cod-Liver Oil, pressed from the liver of the codfish, is easily absorbed and assimilated by some. The odor is not pleasant and a little lemon juice, salt, baking soda, or any flavoring substance may be added to make it palatable. The pure oil taken in this way is, perhaps, preferable to the prepared emulsions.

Olive Oil is derived from ripe olives. It is often used when cod-liver oil is not well borne. Many take olive oil for the purpose of rounding out the figure with fat. If the system will assimilate fat, taken in quantities, the fat may be stored; but, as a rule, one is underweight because of a failure to assimilate the regular diet and overloading the digestive organs with fat will not cause a better assimilation. If the lack of flesh is due to sluggish assimilation exercise should always accompany a diet for the building of flesh.

Olive oil, in moderation, is a good food when much heat and energy are required, but if one’s occupation is sedentary, much fat is not necessary.

Cotton-seed Oil is often substituted or mixed with the cheaper grades of olive oil. It is wholesome, if fresh, but has not the pleasing flavor of the olive.

Nut Oils are good, but, with the exception of peanut butter, are not often used. English walnuts, hickory nuts, pecans, cocoanuts, and Brazil nuts contain much oil. Nut oils are not well borne by some, hence nuts must be sparingly used by them. If taken they should be used with salt, and be thoroughly masticated.

Almond oil and olive oil are used in cooking, to some extent.

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To summarize—digested sugar is called dextrose or glucose; digested starch becomes first dextrin, then maltose (animal sugar); digested protein is peptone; and digested fat is saponified fat.

WATER

No food element is more important for the needs of the body than water. It is composed of oxygen and hydrogen. It forms the large part of the blood and lymph.

The body will subsist for weeks on the food stored in its tissues; it will even consume the tissues themselves, but it would soon burn itself up without water, and the thirst after a few days without it almost drives one insane.

Though it produces force only indirectly, it is entitled to be classed as a food, because it composes about two-thirds of the weight of the body and a large part of all the tissues and secretions. Yeo estimates that the supply of water to the body should be averaged at half an ounce for each pound of body weight.

It has been estimated that from four to five pints of water are excreted each day by the body and therefore a similar amount should be consumed daily. 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). Some of this may be obtained from the food.

By reference to Tables I to V it will be noted that water forms a large percentage of all food, particularly of green vegetables and fruits.

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 evaporation from the body may be maintained, 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.

Much of the water taken passes through the system without chemical change and is constantly being thrown off by the skin, lungs, kidneys, and intestines.

Some of the water is split up into hydrogen and oxygen to unite with other substances in the chemical changes carried on during the process of digestion, and some water is obtained from the food by the union of hydrogen and oxygen liberated by the action of the digestive juices.

Few people give much thought to its resupply; yet, ignorant of the cause, they suffer from its loss, in imperfect digestion and assimilation, and in kidney and intestinal difficulties. If it is withheld from the diet for a while, marked changes occur in the structure and processes of the body. The effect is seen in the lessening of the secretions, the increasing dryness of all the tissues, including the nerves, and if the lack is long continued, in progressive emaciation, weakness, and death.

Water 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.

It is constantly being used in the body to form solutions in which the waste products are held so that the eliminative organs may dispose of them.

It is the chief agent in increasing the peristaltic action of both the stomach and intestines, thus aiding in mixing the food with the digestive juices and assisting the movement along the alimentary canal.

It increases the flow of saliva and of the digestive juices and aids these juices in reaching every particle of food.

It dissolves the foods, and helps 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.

The blood carries the water to the various secreting and excreting glands and its increased pressure aids both the secreting and excreting activity. The digestive organs secrete their juices more freely, digestion is aided, more nutriment is rendered absorbable, more carbon dioxid is liberated, and more oxygen is taken into the blood which thereby is made richer and more life-giving.

One engrossed in business or household cares may forget to take water between meals. In such a case, the blood, in order to preserve its volume, must draw the water from the tissues, which, in consequence, become less moist. The mouth becomes dry, saliva is scanty, appetite fails, the digestion is not so active, the digestive and other secretions are lessened in quantity, the food in process of digestion becomes more solid, its absorption in the intestine is more difficult, it moves slowly along the intestinal canal, and constipation results. The body is not so well nourished and falls a more ready prey to disease.

The supply of fluid furnished to the kidneys is not sufficient, the urine becomes more concentrated and irritation may result. The foundation is thus laid for derangements of the kidney function.

To maintain the equilibrium of the body forces, water drinking should be established as a permanent habit and be firmly adhered to as a part of the daily program.

Many claim that one’s thirst, as in the desire for food, is the only safe guide 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. It does not always call for what is good for it.

Plants thrive after a shower because the falling water brings down the impurities in the air which constitute plant food. Rain-water for household use, therefore, should never be collected during the early part of a shower or rain storm.

Spring water, from its filtration through earth rich in mineral deposits, usually contains a certain percentage of those minerals, as salt, sulphur, or iron, dissolved through the action of the carbon dioxid contained in the water. Some of these springs have become famous health resorts. The contained carbon dioxid gives spring water its pleasant, sparkling taste. Spring water is remarkably free from organic life.

Water as used in cities usually needs careful filtration and purification to rid it of its contained sand and other impurities. The housewife whose water supply is derived from rivers does this on a small scale when she strains out the mud and sand from the water which she is often compelled to use when the river is in flood and full of impurities.

Drinking water should be perfectly clear and without odor. Even a small amount of decomposing vegetable or animal matter can be detected by its odor, if the water is confined for a short time in a bottle or closed jar.

The health of the body depends to a large degree on the purity of the water. Contaminated water is a menace to health.

Water which appears perfectly clear may be badly contaminated with typhoid or other germs. For this reason no water should be used until it has been boiled if one is not sure of its purity. Water from wells near barns and cesspools is often impure.

“Hard” water, as derived from wells, is usually rich in calcium and magnesium. When water contains a large percentage of these substances, it usually causes constipation and indigestion and may aid in the formation of gall-stones or gravel.

The kidneys are especially the great eliminators of water and aid in maintaining the equilibrium of the blood. Except in conditions in which they need rest, water should be freely drunk in order to stimulate them to activity and to assist them in throwing off the body waste held in solution.

One cannot form a better habit than that of drinking two or three glasses of water on first arising and then exercising the stomach and intestines by a series of movements which alternately contract and relax the walls of those organs, causing their thorough cleansing.

This internal bath is as necessary as the cleansing of the skin. Often, in gastritis or a catarrhal condition of the stomach, a large amount of mucus will collect in the stomach over night, and the cleansing of the mucous lining of the digestive tract is then most important.

If in good health, two or three glasses of cool water, 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 on seeking new climates, mineral waters, or tonics.

When cool water in the morning seems to chill one, a glass of hot water may be followed by a glass of cool.

The free drinking of water aids the activity of the skin, keeping the tissues moist and the glands active.

Effervescing waters are usually drunk for their cooling and refreshing effect. They should not be drunk to excess as they are usually combined with syrups or sugar and will thus occasion derangement of digestion, flatulence, and in some cases palpitation from the excess of gas which presses on the diaphragm and impedes the action of the heart.

Mineral waters are drunk for the action of the salts which they contain and are used for their laxative or their medicinal effect. Kissengen, Hunyadi Janos, Epsom, Carlsbad, and our own Saratoga are examples of laxative waters. These all contain sodium and magnesium sulphates and are known as “bitter” waters.

Table waters, as Apollinaris, Vichy, or others containing carbon dioxid are refreshing and wholesome and may be used in nausea and vomiting for their quieting effect. Those who are unable to take milk will often find its digestion will be aided if the milk be mixed with Vichy or seltzer water.

When water is used as a hot drink it should be freshly drawn, brought to a boil, and used at once. This sterilizes it and develops a better flavor.

Cold water should be thoroughly cooled, but not iced. Water is best cooled by placing the receptacle on ice rather than by putting ice in the water. Impure or contaminated ice will contaminate water.

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 now rejected 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 need rarely drink while food is in the mouth; the water should be 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.

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, thus aiding digestion.

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 digestive and eliminative activity.

Water taken before meals passes through the stomach before the food, washes away any mucus that may have collected over the mouths of the gastric glands, stimulates them to activity, and prepares the stomach to receive the food.

Results obtained, in building up about twenty thousand thin women, show that the free drinking of liquid at meals has a tendency to increase flesh. Probably one reason for this is the cleanliness and greater freedom it gives to the absorbing and secreting cells of the mucous lining of the digestive tract, the stronger peristalsis it occasions, and the consequent better digestion.

When one wishes to reduce in flesh, water drinking at meals is restricted.

If the contents of the stomach have become too concentrated or solid, the water will render it more liquid, hence will aid the admixture with the gastric juices and will enable it more readily to pass the pyloric orifice.

Drinking at meals, therefore, has many more arguments in its favor than against it.

All who have a tendency to the deposit of uric acid in the tissues, as in gout, should drink freely of water to lessen the deposit of salts from the blood which must maintain its proportion of fluid.

More water should be drunk if the meal consists largely of protein. The nitrogen it contains is eliminated in a short time by the kidneys, the amount of urine is increased, and more water must be drunk to make up the loss.

In sickness, as in fever, the increased respiration causes a corresponding loss of water from the skin and the lungs. If the bowels are active as in diarrhea, much water is lost in this way. The increase in the heat of the body also tends to dry all the secretions, hence water must be taken to keep them in proper fluidity.

The patient is often too ill to ask for water or will forget to ask for it. Constipation may result from this cause. It must be a part of the nurse’s duty to see that a sufficient amount is taken. An excess of cold water, if hastily taken, may cause cramps. If slowly sipped it will do no harm.

Water may be given in fever in the form of lemonade; a small pinch of soda will make it effervescent and more refreshing.

There is no tonic like water, exercise, and fresh air. The safe method is not to allow the habit of drinking water with regularity to be broken, unless for some necessary purpose, and then the habit should be reinstated as soon as possible.

Soft water, that is, water containing no lime or other mineral, is best. Hard water which causes any degree of curdling of soap, or a lime crust in the bottom of a teakettle, renders digestion difficult.

Bacteria are killed and much of the mineral matter is deposited by boiling the water. Boiled water tastes flat or insipid. It may regain its original, fresh taste by filling a jar half full of water, and shaking the jar so that the air passes through the water.

SALTS

The salts of sodium, potassium, magnesium, calcium and some other substances, are necessary for proper bodily functioning. Taken with the food, they pass into the tissues without change and can be recovered, unchanged, from the tissues and the urine.

The uses of some of these substances are not thoroughly understood, but if deprived of them, the nutrition of the body suffers.

Lime (calcium) is necessary for the bones and teeth and to preserve the coagulability of the blood.

Sodium chlorid (common salt) aids the formation of hydrochloric acid and the activity of the pancreatic juice.

The salts of iron are necessary for the blood.

Other salts are also needed to carry on the chemical reactions in the digestive system.

Cereals, all vegetables, fruits, and nuts furnish both calcium salts and sodium, potassium, and magnesium, which are the salts in the blood and lymph. Minerals are also abundant in dried legumes (beans and peas).

Fruits and nuts contain the least amount of these salts, and meats, vegetables, and cereals follow in the order named, cereals, that is the whole of the grain—not the white flour—containing the most. Any diet, therefore, which recommends the use of fruits and nuts to the exclusion of other foods, depletes the system of some of the body-building elements. The system may seem to thrive for a time on such food because, perhaps, of the rest given to overworked organs, but eventually the body lack will manifest itself; anemia may appear or malnutrition become evident.

Milk furnishes salts in proper proportion for building the bones and teeth of the baby; because of the lime which it contains it is a good food for the growing child. After the child is one year old, eggs may be added to the diet. During the first year the albumin and fats in the egg are not well digested. It is especially essential that children be furnished milk and eggs that they may be assured of the proper proportion and quantity of calcium salts for growth.

Sodium chlorid (common salt) has been for ages recognized as an important element in food, so important that in Eastern countries it is the symbol of hospitality and friendship.

When taken in moderate quantities, salt increases the activity of the gastric secretion and aids the appetite. When taken in excess, as many who have formed the salt-eating habit do, it is an irritant to the mucous membrane of the stomach and intestines and may interfere with nutrition, causing dyspepsia, gastroenteritis or diarrhea from the continued irritation.

The habit indulged by some of nibbling at salted nuts of various kinds, at and between meals, may for a short time satisfy the needs of the body for more salt than is usually taken with the food, but such a habit persisted in will cause acidity of the stomach from overstimulation of the hydrochloric acid producing glands; it will also decrease the fluidity of the blood by causing the water to be drawn from the blood for the use of the tissues. Irritative action is also exerted on the kidney, as any excess of salt is excreted by this organ. For this reason salt is often prohibited for those suffering from any inflammation of the kidney, in Bright’s disease, etc.

When chemical tests show an excess of hydrochloric acid, salt should be omitted from the diet.

A diet consisting largely of vegetables needs the addition of sodium chlorid to supply sufficient salt for body uses; 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.

Potassium is next in importance to sodium as it constitutes the chief salt in the muscles. It also aids the action of the digestive secretions and the maintenance of the reaction of the urine. Potatoes and apples are valuable foods on account of the potassium they contain.

Calcium, if in excess, may cause the formation of calculi, renal or biliary. It is also found in the tartar which accumulates on the teeth, in the hardening walls of the arteries in arteriosclerosis, etc. All of the cabbage family are rich in calcium. Many mineral waters and the water from many wells contain it in excess.

Those addicted to gall-stones, gravel, etc., should particularly avoid “hard” water.

Phosphorus and sulphur are obtained by the body from eggs and milk and from such vegetables as corn, cauliflower, asparagus, and turnips.

Iron is necessary in forming the pigment of the red blood corpuscles.

If, through some disturbance in digestion, absorption or assimilation, the iron taken in the food is not utilized, or is insufficient in amount, the blood-making organs do not receive the necessary amount of this substance and the red corpuscles are not formed in sufficient numbers. The blood becomes poor in hemoglobin, and the individual becomes pale and loses vitality. This condition is known as anemia.