In taking up this new group of food substances, that of vegetables and fruit, there is need for emphasis on increasing their consumption in the United States. We use a comparatively large amount of fresh fruit, but the total amount of fruit and vegetables consumed is low when measured by their value in the diet. We fall short particularly in the use of the staples, especially the potato, cabbage, beets, and turnips, as compared with the amount used on the continent of Europe. To be sure, we use a relatively large amount of string beans and peas, but small amounts of the matured and dried beans and peas. The potato in this country is regarded not as a staple of the diet, as it is in Germany, but as an addition to it like a green vegetable. Though regularly on our tables, it appears only in small quantities usually once a day, though sometimes twice. Since it contains 20 per cent of starch it could easily be used to replace grain products in a mixed diet, counting five parts of potato the equivalent of one part of grain. Singularly enough, universal as is its use, it is shipped from one farming community to another farming community which adds the cost of transportation and storage to its price to the consumer. The price, of course, when taken in relation to the food value ought to approximate that of grain, pound for pound one fifth that of grain.

There are whole sections of our population in which the leaf vegetables are practically unknown. Their consumption is low all over the United States except among the foreign-born. Neither are the root vegetables used to so great an extent as they should be.

The value of vegetables in the diet does not lie entirely in their actual chemical composition for they all contain a large amount of water, sometimes as much as 95 per cent, especially such foods as tomatoes, cabbage, celery, and berries of different kinds. The amount of protein is small, but they are a cheap source of this important food nutrient when vegetables are abundant. It is to be noted that in respect to the protein content, potatoes are not so valuable in the diet as bread, since potatoes contain only about 2 per, cent of nitrogenous matter whereas bread contains 12 per cent. The amount of starch in the vegetables varies with the type of vegetable or fruit. As we have already said, the potato contains 20 per cent, the sweet potato has about the same amount, and an unripe banana about 22 per cent. Some starch is found in all of the underground vegetables but in no other of them is there so much as in the potato. We also find traces in the vegetables of the other carbohydrate, sugar, which may increase in quantity to the 15 per cent found in sugar beets and to the far larger quantity found in fruits, especially the dried ones.

The chief value of the vegetables in the diet, however, is as a source of mineral salts. They are an important source of iron, and stand next to milk as a supply of calcium. They also contain potassium and the sodium salts of organic acids. These form alkaline or basic substances in the blood and tissues which help to maintain the normal neutrality of the blood and are capable of neutralizing acids produced in protein metabolism. For this reason alone the greater the quantity of meat, fish, and eggs used in the diet, the more vegetables and fruit should be used. To put the same statement in terms of money, the same amount should be spent for milk, fruit, and vegetables as is spent for meat, fish, and eggs.

Composition

A source of minerals

Besides these definite chemical constituents we have been told recently by Dr. McCullom and others that the leaves of plants contain minute quantities of some substances that are absolutely essential for normal growth and health. It was found by experimentation that it was impossible to nourish young animals adequately on seeds alone or the products of seeds. These were lacking in three important points; their proteins were of poor quality, they were poor in three of the nine mineral elements required, and they were lacking in that "vitamine" known as the "fat-soluble A."These deficiencies were made up by a combination of leaves and milk with the seeds, or of meat, leaves, and seeds. A mixture of leaves and seeds alone gave fairly good results. Hence the leaves of plants are the second protective food, milk and its constituents being the first. Experiments are being made to get meals and flour in which dried and pulverized leaves are added to the product of the seed. For instance, 20 to 30 per cent of dried spinach or celery makes up the deficiencies of a seed product.

This "fat-soluble A" which is found in the leaves of plants is present in the germ of the grain to a slight extent but is usually lost in the milling process, nor is it found in the vegetable oils extracted from the grain.

A source of "vitamines"

Both "vitamines" "A" and "B" are present in all vegetables so that it is perfectly possible to have a successful diet entirely of foods of plant origin. It is not altogether wise, however, as variety of diet tends towards safety and towards a more perfect nourishment of the body. There is no harm in using milled products or canned goods if their deficiencies are made up by combinations with plenty of fresh foods. The "fat-soluble A" is thought to be unchanged by heat, but the "water soluble B" is in time hurt by heat and more rapidly if in alkaline solutions.

There are several ways of grouping vegetables and fruit. They may be grouped according to their general composition, such as (1) watery, (2) starchy, and (3) sweet. In the first group would come all the green vegetables, the berries, and other watery fruits such as pears, apples, and cherries. In the second group would come the potatoes, both white and sweet, bananas, and some tropical fruits such as the breadfruit. Under the third heading we would place the dried fruits, such as dates, figs, and raisins. Another way of grouping the vegetables alone would be above ground and below ground. And still a third way would be according to the part of the plant that is used, as roots (beets, carrots, and turnips), stems (asparagus and celery), leaves (spinach, beet greens, lettuce, cabbage, etc.), flowers (cauliflower, Brussels sprouts), and fruit (tomato, cucumber, corn, peas and beans, etc.).

For cooking purposes it is somewhat easier to divide them into the two groups of strong-juiced and sweet-juiced. Certain vegetables like onions and cabbage are always strong-juiced, while others, such as beets and carrots, may be strong-juiced in the winter, and sweet-juiced when they are young and fresh from the home garden. Strong-juiced vegetables should be cooked in a large quantity of water in order to modify the flavor, and the water may be changed once or even twice during the course of the cooking. For sweet-juiced vegetables, however, the purpose should be to save all the flavor possible so that cooking in water is wasteful. If water at all is used, as small a quantity as possible to keep the vegetables from burning is all that is necessary and this should be made into a sauce and served with the vegetable. If a larger quantity of water is required as for corn and asparagus, it should be boiling when the vegetable is put in, and drained off just as soon as the vegetable is tender. It takes far less time than is usually supposed to cook these vegetables sufficiently. Water in which vegetables are cooked can be used in making soup or in gravies. Boiling vegetables is necessarily a wasteful way of cooking them since the mineral salts for which they are particularly valuable in the diet are partially lost in the water. It is better to steam them or bake them. In fact, a properly baked potato is the only form in which a potato should be given to a very young child or an invalid. If a fork is run into the potato when it is taken from the oven, it allows the steam to escape and prevents the potato from becoming soggy as it cools.

Grouping of vegetables

Cooking of vegetables

The aesthetic qualities of fruit are the ones that are emphasized since the purpose of the fruit by nature is to insure the scattering of the seed, hence it is highly colored and flavored in order to attract birds and insects. We have then certain definite uses for fruit in the diet besides the ones we have already mentioned. They are a valuable source of

Uses of fruit