CLASSIFICATIONOF FOOD ELEMENTS
Byfoodstuffis meant the chemical elements, appropriated by the animal for the use of the body, as described above. Byfoodsis meant those articles of diet found in the market which contain the chemical elements used by the body in various combinations. Bread, for example, contains all of the foodstuffs and has been called the staff of life, because it sustains life. Foods may contain elements, not foodstuffs, and not used by the body, but cast out as waste, while certain foods, such as sugar, cornstarch, olive oil, and egg albumen, contain only one foodstuff, as will be noted in the following classification of foods and foodstuffs—grouped according to the body uses.
There are many classifications but the following tables, as compiled by a leadingdietitian[2]for his practical work in classes, are clear and concise.
The above classifications are made because of the preponderance of certain elements in them, not because they do not contain other substances; e.g. vegetables are mixtures of sugars and starches; fruits are mixtures of sugars, vegetable acids, and salts; milk, legumes, cereals, and nuts contain a more equal division of sugars, fats and proteins and are therefore represented as carbo-nitrogenous; lean meats, with the exception of shellfish, contain no starch, but all meats contain fat, protein, and water, and all, except liver, contain ash.
In the table below, examples are given of foodstuffs in which the chemical elements are almost pure representatives of their classes. Cornstarch, sago, and tapioca are almost pure starch, containing very little of any other element; glucose, cane sugar, syrups, and honey are almost pure sugar; butter, lard, and olive oil are nearly all pure fat; egg albumen, gluten, and lean meat are almost pure protein.
Theproteinscontain nitrogen, sulphur, and phosphates. The predominance of nitrogen has given the proteins the name nitrogenous. The carbonaceous foodscontain none of these elements, but are rich in carbon, hence the name carbonaceous.
As previously stated, no food contains but one element of foodstuffs and all elements are formed into compounds of plant life from the elements in the soil, air and water by the action of the sun’s rays. The rays of heat and light seem to store something of their power in latent heat and energy within the combinations of these compounds. The end of plant life is the completion of its compounds,—it first generates the compounds, then matures them, and then dies.
Allorganicmatter is thus formed by the action of the sun’s rays uponinorganicmatter. All meats are first in the form of plant life and are converted into other compounds by the chemical processes of the animal. This chemical action of the animal converts the energy latent in the foods into more concentrated form. The animal thus performs a part of the chemical work for man.
The classification of foods, as previously stated, is based upon the principal organic foodstuffs contained. Proteins contain carbon and salts, and carbonaceous foods contain salts and nitrogen, but these arenot in appreciable quantity. The preponderance of these elements determines the use of the foodstuffs in the body. It will be remembered that the chief uses are the production of heat and energy, the building of new tissue of the growing child, and the repair of the waste in the child and the adult.
Water
No one element of food is more important for the needs of the body than water. It comprises about two-thirds of the body weight and is a component part of all foods. It is composed of oxygen and hydrogen.
In order that the body may do efficient work in digestion and in the distribution of the nutrient elements of the foods, and that the evaporations from the body may be re-supplied, the water in the foods, together with the beverages drunk, should consist of about seventy-five per cent liquid to twenty-five per cent nutrient elements, or about three times as much in weight as proteins, fats, and carbohydrates combined. If undue evaporation or perspiration is occasioned, a larger proportion is required.
Water passes directly into the circulation without chemical change. It is beingconstantly evaporated through the lungs and the skin, and every forty-five seconds it passes from the kidneys into the bladder.
The average individual at normal exercise, requires about seventy-one and one-half ounces of water daily, which equals about nine glasses (one glass of water weighs one-half pound); a part of this is consumed in the food. By reference to the following tables it will be noted that water forms a large percentage of all food, particularly of green vegetables and fruits.
The importance of water for children must not be overlooked. It is the heat regulator of the body, and the more energy used, either in work or in play, which results in more heat and evaporation, the more water is required. An animal, if warm, immediately seeks water.
The body will subsist for weeks upon the food stored about its tissues; it will even consume the tissues themselves, but it would burn itself up without water, and the thirst after a few days without water almost drives one insane. It should be furnished freely, in small quantities at a time, to fever patients.
Few people, give much thought to its re-supply; yet they suffer from the loss ofit, in imperfect digestion and assimilation, and with kidney and intestinal difficulties, ignorant of the cause.
Water softens and dissolves the food and aids in its absorption; it is one chief agent in increasing the peristaltic action of both the stomach and intestines, thus aiding in mixing the food with the digestive juices and aiding the movement along the alimentary canal; it increases the flow of saliva and of digestive juices and aids these juices in reaching every particle of food more promptly; it aids in the distribution of food materials throughout the body, carrying them in the blood and the lymph from the digestive organs to the tissues, where they are assimilated; it forms a large part of blood and lymph.
The theory has long been held that water drinking at meals is injurious, the objection being that the food is not so thoroughly masticated if washed down with water, and that it dilutes the digestive juices. But this theory is not so strongly held as formerly—in fact, it is now rightly disputed by the best authorities.
When water drinking at meals is allowed to interfere with mastication and is used to wash down the food, the objection is well taken, but one rarely drinks whilefood is in the mouth, the water being taken at rest periods between mouthfuls.Thorough mastication and a consequent free mixing of the food with saliva is one of the most essential steps in digestion, and the flow of gastric juice, as the flow of saliva, is stimulated by the water.
If, on the other hand, the food is not thoroughly masticated, water is most essential to furnish that which the saliva would otherwise supply to soak up and dissolve the food, in order that the gastric juice may more readily reach all parts of it.
It is singular that the use of water at meals has long been considered unwise when the free use of milk, which is about seven-eighths water has been recommended.
The copious drinking of cool water from a half hour to an hour before a meal will cleanse the stomach and incite the flow of saliva and gastric juice. Moreover, the digestive cells secrete their juices more freely and the sucking villi absorb more readily when the stomach and intestines are moderately full, either of food or water, and to fill the stomach with food requires too much digestion. The waterpasses through the stomach before the food.
In building up about seven thousand thin women, results show that the free drinking of liquid at meals has a tendency to put on flesh. Probably one reason for this is because of the cleanliness and greater freedom given to the absorbing and secreting cells of the mucous lining of the digestive tract, as well as to the stronger peristalsis.
It will be noted that water drinking at meals has many more arguments in its favor than against it.
One important use to which water is put is to cleanse the digestive tract and the kidneys. This cleansing within is more necessary than the cleansing of the surface of the body. One cannot form a better habit than that of drinking two to three glasses of water upon first arising and then working the stomach and intestines by a series of exercises which alternately relax and contract their walls, causing a thorough cleansing of these organs.
In case of gastritis, or a catarrhal condition of the stomach, often a pint of slimy mucus will collect in the stomach over night and the cleansing of the mucous liningof the digestive tract is then most important.
The drinking of warm (not too hot) or cold water in the morning depends upon the condition of the individual. If in good condition, two to three glasses of cold water, the vigorous exercises for the vital organs, and deep breathing ofpureair, followed by a cold bath, will do more tokeepthe health, vigor, clear skin, and sparkling eye than fortunes spent upon seeking new climates, mineral waters, or tonics. There is no tonic like water, exercise, and fresh air, as above prescribed.
Soft water, that is water containing no lime or other mineral matter, is best for cooking purposes; hard water, which causes any degree of curdling of soap, or a lime crust in the bottom of a tea kettle, is hard on digestion. Bacterial germs are killed and much of the mineral matter deposited by boiling the water. For drinking purposes it should be aerated that it may regain its original, fresh taste, otherwise boiled water tastes flat or insipid. It may be aerated by filling a jar half full of water, leaving the other half for air, and then shaking the water in the jar so that the air passes through it.
Many claim that one’s thirst, as in the desire for food, is the only safe guide, as to the amount and time of drinking, but these desires are largely matters of habit, and tastes are often perverted. Unless the condition is abnormal or the mind becomes so intensely active that one fails to listen to the call of nature, the system calls for whatit has been in the habit of receivingand at the stated times it has been in the habit of receiving it. The safe method is to form the habit of eating and drinking a stipulated amount at regular periods and not allowing this regular habit to be broken, unless, for some cause, the system be out of order, and then the habit should only be broken for a time.
Salt
Milk furnishes salt in proper proportion for the baby, and later, when the child is through nursing, eggs should be added to the diet of cow’s milk. It is especially essential that growing children be furnished milk and eggs that they may be assured of the proper proportion and quantity of calcium salts, as these form the substances of bones and teeth, which constitute about one-sixth of the body weight.
All vegetables, fruits, cereals, legumes, and nuts furnish both calcium salts and sodium, potassium, and magnesium, which are the salts used in the blood and lymph. Minerals are abundant in dried legumes, (beans and peas). A diet consisting largely of vegetables needs the addition of sodium chlorid (common table salt) to supply sufficient salts for foods; likewise more salt than is contained in grass and fodder is needed for animals, particularly for those producing milk. The scientific farmer salts his cattle regularly, while wild animals travel miles and form beaten paths to springs containing salt.
In rectal feeding, it is known that food absorbs more readily through the large intestine if salted. It is probable that salt, in normal proportions, also aids absorption in the stomach and small intestine.
Salt should not, however, be used immoderately.
The minerals of the food, or of the body, form the ashes in burning.
Iron
Iron is an inorganic substance and is necessary in making red blood corpuscles.
If, by some disturbance in the digestion, absorption, or assimilation of food, moreiron is excreted from the body than is made use of from the food, the blood making organs do not receive sufficient iron and the blood is lacking in red corpuscles. It becomes poor in hemoglobin and the individual becomes pale. This condition is known asAnaemia.
Where there are not sufficient red blood corpuscles, it is of vital importance that one keep up a good circulation; the stomach, intestines, liver, and spleen must be strengthened through exercise and one must breathe deeply of pure air, for the red blood corpuscles are oxygen carriers, and the insufficient supply must do double duty or the waste of the system will not be oxidized and eliminated.
A diet rich in iron must be supplied. It will most often be found that one whose blood is lacking in hemoglobin and in the proper proportion of red blood corpuscles, has had a dislike for the foods rich in iron, or, perhaps, has not been able to get the right kind of food.
The yolks of eggs, the red meats (such as steak, mutton or the breast of wild game), and the deep colored greens, (such as spinach, chard, dandelions, etc.) contain a goodly proportion of iron. The dark color of greens and of the dark meatsis given to them by the iron which they contain. The dark leaves of lettuce, celery, and cabbage contain iron, but these vegetables are apt to be bleached before being put upon the market.
The yolks of two eggs are better than one whole egg, as the iron is in the yolk. A good way to take the yolk of eggs is in egg lemonade or in eggnog, with a little nutmeg for spice.
FOOTNOTES:[2]Winfield S. Hall, Ph. D., M. D., Prof. of Physiology, Northwestern University Medical School, Chicago.
[2]Winfield S. Hall, Ph. D., M. D., Prof. of Physiology, Northwestern University Medical School, Chicago.
[2]Winfield S. Hall, Ph. D., M. D., Prof. of Physiology, Northwestern University Medical School, Chicago.