Combination Important

Two proteins both incomplete may be deficient in different ways so that the combination of two or more incomplete proteins may be sufficient to supply all the nitrogenous combinations and thus make a complete protein food.†

A monotonous diet of grain being also deficient in alkaline salts (see footnote, page 27) and, as or-narily prepared, lacking in certain vital substances called vitamines by Funk, care must be taken that these be supplied in other ways. (See Chapter IX (Vitamines)).

The Protein Of Corn

A single grain usually contains more than one protein as, e. g. wheat with its gliadin, a protein that will maintain body weight, and its glutenin, one which will stimulate growth, and while zein a prominent protein of corn is unable to even maintain the body, yet corn also contains another protein called globulin which will maintain and even cause growth. If intelligently combined with other foods, corn is a valuable addition to the dietary. It, however, could not be depended upon as a sole source of protein. It is interesting to note that the protein of green vegetables will supplement the protein of corn.

The proteins of meat, milk, and eggs have been found to be complete in themselves. Accordingly a diet of grains and milk is a complete food in so far as its proteins are concerned. Recent experiments have shown that the protein of the peanut and the soy bean are of very good character.

†The proteins of the pea or bean, when taken as the sole source of nitrogen, are of very low biologic value, and they will not supplement the protein of corn though they improve the protein of wheat. Bean protein will not supplement those of oat, though pea proteins and oat proteins are said to. supplement each other.

Know Foods. Avoid Monotony

Again we would emphasize the need for a knowledge, by the vegetarian, of foods and their values that the meatless diet may not prove to be a deficient one. A complete diet without the use of flesh food is very possible and a great advantage, but care must be taken that intelligent combinations be made and that monotony be avoided. Green vegetables and fruits supply many elements lacking in grains and with a knowledge of food values and an intelligent daily variation in foods served one need be in no danger of limiting his diet to one deficient either in quantity or quality of protein. But how important that the housewife be educated along these lines and so be understandingly efficient as she carries on the important work of supplying the family table.

Following are grouped some of the more important staple protein foods in such a way as to show at a glance those having the highest proportion of the nitrogenous element.* With these, many attractive dishes may be prepared and, as meat substitutes, supply the necessary protein.

♦The percentages of protein in these tables are of the total food values and not of the weight.

Class 1. Very High Protein Foods

(Foods of high total food value of which the protein is above 20%).

"Soy beans introduced in the U. S. more than 100 years ago primarily for use as a forage crop, are in reality one of the most nutritious of the legumes when used as human food, according to specialists of the U. S. Department of Agriculture. . . . Since they furnish proteins and valuable fat they are especially important to turn to as an emergency addition to the usual dietary or as a substitute for other foods furnishing protein and fat. Moreover, the fact that they contain no starch makes them valuable for invalids who cannot eat starchy foods." - Food thrift series No. 2, U. S. Department Of Agriculture.

Class 2. High Protein Foods

(Foods with high total food value of which the protein is from 15 to 20%).

Class 3. Medium Protein Foods

(Foods with high total food value of which the protein is from 11 to 15%).

Class 4. Foods With Low Total Food Value Of Which A High Proportion Is Protein

* See Chapter IX (Vitamines).

♦Complete proteins, or proteins containing all of the tissue building stones, are found in the foods of Class 4 as well as in the outer-layer of all other vegetables, the outer layer and germ of grain, and in milk, eggs, and meat.