Read Ebook: What to eat and when by Cocroft Susanna
Font size: Background color: Text color: Add to tbrJar First Page Next Page Prev PageEbook has 2284 lines and 128496 words, and 46 pagesThe 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. 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. 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. 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. CLASSIFICATION OF FOOD ELEMENTS 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. { Water { Corn-Starch { Inorganic { Salts Starches { Sago { { Tapioca { { Carbonaceous { Glucose { { { Syrups { { { Honey Foodstuffs { { { { { Lard { Organic { Fats { Olive Oil { { { Butter { { { { { Egg Albumin { Nitrogenous { Proteins { Gluten { 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. 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. Add to tbrJar First Page Next Page Prev Page |
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