Volume 3 — Lesson XIII

CLASSIFICATION OF FOODS AND FOOD TABLES

LESSON XIII

Simple Classification of Foods

While there is a dominating substance in all foods, yet they usually contain many compounds which render them, from a chemical standpoint, very difficult to classify accurately. For example, the principal nutrients in wheat are carbohydrates (starch and sugar), yet wheat contains mineral salts, fat, and protein, the latter being a compound consisting of carbon, hydrogen, oxygen, nitrogen, and sulfur. Wheat would, therefore, be placed in the carbohydrate class, but it would overlap into several other classes. What is true of wheat, is true of nearly all other articles of food. Furthermore, foods do not chemically reproduce themselves when taken into the body, but in the process of metabolism they are converted either into other elements or into other compounds. From this it will be understood that the articles listed under the following headings are classified according to the nutritive substance which predominates in them, and are given for the purpose of guiding the practitioner in the selection of such foods as will supply the various chemical constituents of the body.

Foods which contain two or more substances in generous proportions may appear under two or more of the following headings, as in the case of peanuts. This humble article of food contains 19 per cent carbohydrates, 20 per cent protein, and 29 per cent fat, hence it is listed under the three headings—carbohydrates, proteids, and fats.

The tables comprise the best selections of food available in all countries and at all seasons of the year. They contain everything the body needs under the varying conditions of age, climate, and activity, except, perhaps, in some parts of the frigid zone.

In compiling these tables I have selected only such articles of food as experience has proved most useful.

SIMPLE CLASSIFICATION OF FOODS BASED ON PRINCIPAL NUTRITIVE SUBSTANCES

/——————Carbohydrates——————\ Fats Proteids Foods rich in Mineral Salts

Chocolate Honey Vegetables— Butter Cheese Vegetables—

Fruits— Nuts— Asparagus Cheese Eggs Asparagus

Dates Chestnuts Bananas Chocolate Fish Beet-tops

Figs Peanuts Beets Cream Legumes— Cabbage

Grapes Pignolia or Cabbage Nuts— Beans—dried Carrots

Persimmons pine nuts Carrots Almonds Lentils—dried Celery

Raisins Sirups Celery Brazil-nuts Peas—dried Dandelion

Grains— Sugar Lettuce Cocoanuts Milk Green peas

Barley Tapioca Onions Hickory-nuts Nuts— Lettuce

Corn Parsnips Peanuts Peanuts Onions

Oats Potatoes—sweet Pecans Pignolia or Radish-tops

Rice Potatoes—white Pignolia or pine nuts Romaine

Rye Pumpkin pine nuts Poultry Spinach

Wheat Spinach Walnuts Vegetables— String beans

Squash Oils— Cabbage Turnip-tops

Turnips Cottonseed Lettuce Watercress

Nut-oil Onions Wheat bran

Olive-oil Spinach

Turnips

Wheat bran

PURPOSES WHICH THE DIFFERENT CLASSES OF FOOD SERVE IN THE HUMAN BODY

While all the articles of food in the four above-named classifications contain other elements than the one under which heading they appear, yet the body uses or appropriates them for the following purposes:

PURPOSE OF CARBOHYDRATES

The carbohydrate substance in food is used by the body chiefly for the purpose of keeping up body-weight; that is, for the purpose of supplying the various fluids which fill the cell-structure. If one is suffering from emaciation, the carbohydrate element in food should predominate. While some of the more soluble proteids, especially milk and eggs, will give a rapid gain in weight, the weight will not be permanent unless sufficient carbohydrates are taken to supply the blood with all the required elements of nutrition, or, in other words, to level or to balance the body requirements.

PURPOSE OF FATS

Fats are used by the animal body primarily for the purpose of producing heat. Food is burned or oxidized in the blood, undergoing very much the same action as does the combustion of coal in a grate. The heat thus generated is delegated to the blood, and the blood, by its circulation, distributes this heat throughout the body. The carbon dioxid or waste matter formed during the circulation, is carried to the lungs, where it reunites with the oxygen which we breathe, and thereby again passes back into the atmosphere.

PURPOSE OF PROTEIDS

Proteid is a compound containing chiefly nitrogen, oxygen, and carbon. Its purpose is to form the muscular and the tissue structure of the body. To use a homely illustration, proteid may be compared to the material which makes the honeycomb, while the carbohydrate substance may be compared to the honey; that is, to the fluids which fill the cells.

Those performing heavy or active muscular labor should eat liberally of the proteid class of foods.

Under normal conditions, natural hunger will call for the quantity of proteid needed. The tendency, however, should be toward the minimum; that is, one should take the lowest quantity of proteid that the body requires to keep up the cell-structure. (See Lesson VI, p. 216.) Modern investigations have shown that, in many cases of extreme athletic tests, a low proteid diet has given the greatest endurance. This is accounted for by the fact that nearly all carbohydrates, especially of the grain family, contain from 8 to 12 per cent of proteids, which is quite sufficient, in many instances, to supply the body with all the tissue-building material necessary.

Inasmuch as the several nutritive elements found in a single article of food are better proportioned by Nature, than man can usually proportion them, the relation of one substance to another will be better divided if the entire meal be made to consist of only one kind of food, and both digestion and assimilation will therefore be more perfect. Under these conditions the blood will be laden with very little waste matter, which is the thing that reduces our powers of endurance. Therefore, when it is possible to secure the carbohydrate, the proteid, and the fatty substances from a single article of food which will give to the body greater strength and endurance than when we secure these substances from several sources, we should confine our menus to single articles of well-proportioned food. This thought, carried to its logical end, leads one more and more, as experience progresses, toward the mono-diet system.

PURPOSE OF MINERAL SALTS

Mineral salts serve two distinct purposes in the body:

1 They assist in building up the cartilage and the body-structure

2 They assist in the digestion, and in the dissolution of other foods, especially of the carbohydrate group, and more especially of the grain family

Grains are very difficult to subdivide into their constituent elements; that is, to reduce to a solution so fine that assimilation will be perfect. A liberal use of the foods containing mineral salts aids very materially in this process of solution.

DIFFERENCE BETWEEN DIGESTIBILITY AND ASSIMILABILITY

The true interpretation of the word "digestion" is the preparation of food by the action of:

1 The saliva

2 The gastric juice

3 The bile, and

4 The pancreatic juice

When food is properly prepared by mastication by the time it reaches the pancreas, it should be thoroughly split up or subdivided, in which state it is ready for assimilation.

The true interpretation of the word "assimilation" is the absorption of all food substances through the walls of the intestinal tract, and the final passing of them into the circulation.

It is nothing unusual, however, for a person to become afflicted with predigestion, and, at the same time, with poor or faulty assimilation; in other words, digestion being too rapid, and assimilation being too slow. This condition frequently occurs in cases of superacidity. On account of the excess of acid, the food digests or passes from the stomach prematurely; that is, before it has been dissolved by the action of the hydrochloric acid. The food, thus super-charged with acid, passes from the stomach into the lower intestines, and sets up a condition of irritation. This irritation or swelling of the mucous surface (lining) of the intestines, closes the small canals, or winking valves, as they are sometimes called, thus seriously interfering with the passing of the dissolved food matter into the circulation.

The following table is designed to show the comparative assimilability of the leading articles of food, together with their starch, sugar, and water content:

TABLE SHOWING COMPARATIVE ASSIMILABILITY AND CARBOHYDRATE AND WATER CONTENT OF CEREALS, LEGUMES, AND VEGETABLES

FOOD Assimilability Percentage of

Starch Sugar Water

CEREALS

Barley Somewhat Difficult 61.6 1.5 13.7

Buckwheat Difficult 48.0 6.0 12.0

Corn Difficult 60.5 3.0 12.2

Oats Difficult 54.0 2.0 12.0

Rice Medium 79.1 0.4 13.0

Rye Somewhat Difficult 62.0 0.95 15.06

Wheat Medium 62.0 0.95 15.08

LEGUMES

Beans—dried Good 53.0 3.0 12.0

Lentils—dried Good 50.0 2.0 11.0

Peas—dried Good 57.0 4.0 11.0

* VEGETABLES

Banana—very ripe Very good 8.0 11.0 48.0

Beets Good 1.7 7.8 68.0

Cabbage Medium 4.3 — 78.0

Carrots Very good 1.0 6.1 83.0

Parsnips Very good 1.5 6.0 82.0

Potatoes { Sweet Good 24.4 5.6 69.0

{ White Very good 19.8 .7 72.0

Pumpkin Very good 3.9 2.0 74.3

Squash Very good 4.1 1.2 83.0

Turnips Good 5.1 2.1 91.0

* While all the vegetables mentioned in the above table belong to the carbohydrate class, yet the starch element contained in them is very much more assimilable than the starch contained in grains or legumes, therefore these vegetables may be eaten freely by those having rheumatic or gouty tendencies.

The starch and the sugar content in fresh vegetables appears low owing to the fact that they contain a large percentage of water. Eliminating the water, these foods rank in their starch and sugar content with cereals and legumes, and are much more easily digested and assimilated. In other words, if the chemist should reduce the water content to the same per cent as that of cereals, the carbohydrate content would rise in the same ratio as the water content is reduced. Both the starch and the sugar content of these vegetables is more digestible, and more readily assimilated than the starch and the sugar found in cereals and legumes.

PURPOSE OF THE VIENO TABLE

The student should remember that not only the quantity but the quality of food must be considered. The vieno system of food measurement, as herein explained, is the simplest system of food measurement that has ever been published. It is amply complete, and accurate enough for the purpose for which it is intended, and that is the calculation of the energy and the available nitrogen contained in natural dietaries.

This measurement is really a quantitative measurement; that is, it measures the quantity, not the quality. In order to have a full knowledge of a bill of fare, it is necessary to know, in addition to the quantity, the exact chemical nature of each particular food, and also to know the other foods with which that food will combine.

This food table tells accurately the amount of energy that may be derived from food by chemical analysis, but it does not tell the amount of energy that the body must expend in the work of assimilation. This cannot be given in a table, because it varies with the individual and the condition of his digestive organs.