Watery foods, like many vegetables and fruits, normally give less fuel. A person could not live on lettuce any better than a house could be heated with tissue paper.

If the food does not supply enough energy, a person will burn up part of his own body for fuel and will grow emaciated. Far too often we find children of the very poor who are undernourished because of lack of food fuel. Sometimes even well-to-do young people half starve themselves because they get "notions" about food. One of the terrible tragedies abroad is the hundreds and thousands of men and women and children who are worn and thin and sick for lack of food.

We need food, too, to keep the organs of the body running smoothly. Abroad, people are suffering not only because they have not enough food, but because they have not the right kinds of food. Milk and vegetables and fruits are especially useful. They are the chief sources of the much-needed mineral salts and the two vitamines. The vitamines are substances of great importance about which has centred much discussion lately and which scientists do not yet fully understand, though they realize that they are essential for the growth of children and for health in adults.

The protein of food is used to build the body if we are young, and to restore the daily wear and tear if we are older. The mineral salts are also necessary for this purpose. Protein will be discussed further in the chapter on meat and meat substitutes, but it should be realized here that the protein we eat comes not only from these foods, but also from the cereals. Cereals supply a full half of the protein of many diets.

Cereals are therefore important for their fuel since they are rich in starch, and for their protein, and, if we eat the entire kernel, for their mineral matter and vitamines. They also have the pleasant flavor and texture which we have grown to like.

Wheat is no better than any of the other cereals. It possesses absolutely no nutritional advantage for man or beast over oats, corn, and rye. It has no more protein, and no better protein. It has no more fat and no better fat. It has no better mineral salts and in no larger amounts. It has no more fuel or better fuel. It is just one of the cereals, and there is not the slightest evidence that it is the best one. It has merely become one of our habits.

Corn and wheat and the other cereals are just as well digested if equally well prepared. A soggy piece of wheat bread may, of course, be less readily digestible than a well-made piece of corn-bread, but that is a question of skill in cooking, not of difference in cereals. Complaints have been heard in England about the war bread. It is true that it may be hard on those of frail digestive powers to change their food habits in any way, but Hutchison, an eminent London physician, in tracing down complaints, found that frequently people laid to the new bread ailments from which they had suffered before the war. "When in doubt, blame the war bread," seemed to be the motto.

THE SOCIAL IMPORTANCE OF CEREALS, ESPECIALLY WHEAT

The world eats more cereals than any other kind of food. They are so widely available, so cheap and nutritious, that they are a main reliance of the human race. A shortage is always extremely serious.

Not only is an abundance important, but an abundance of the accustomed kind. In parts of India, the inhabitants use rice as almost the only cereal. When the rice-crop failed some years ago, thousands of people died of starvation with a supply of wheat available. They did not know the use of wheat as food.

Countries like France, which use their cereals chiefly for bread, are the most dependent on wheat, since wheat is the most easily made into bread.

In the United States cereals make up almost one-third of our food. Although wheat in most parts of the country has been the main dependence, we have used a much greater variety of cereals than most people, so that it is comparatively simple for the majority to make increased use of them.

The very poor must depend largely upon cereals because they can get more for their money from them than from other foods. Cereals, to most of them, mean bread. It is such a large part of their diet that doing without it means a far more fundamental and difficult change in their food habits than for the well-to-do with greater freedom of choice. Besides, the already overburdened working woman must get her bread in the easiest possible way—a ready-made loaf from the baker. The burden of scarcity or high prices falls on those least able to bear it.

Europeans eat even larger amounts of wheat than we. Over half the food of the French is bread, so if the wheat shortage were near the danger-line, it might lead to a serious weakening of the marvellous courage of the French people.

WHEAT FLOUR IN WAR-TIME

To use this country's share of the short supply of wheat to the greatest advantage the Food Administration has changed the making of flour to include more of the wheat-kernel. The difference between peace and war time flour is easily understood if the structure of grains is considered. Wheat and other cereals have kernels much alike; all have three principal parts:

The outer covering, called bran, is made up of several layers. This is rich in important mineral salts, and the rest is largely cellulose, or woody fibre.

The germ is the small part from which the new plant will develop. Here the small amount of fat in the kernel is stored.

The largest part of the kernel, called the endosperm, contains the nourishment to be used by the plant as it begins to develop. This is mostly starch, with some protein. It is the part of the wheat, for instance, which is chiefly used to make our white flour.

The kind of flour made depends on how much and what parts of the kernel are used. Graham flour is manufactured by grinding practically all of the wheat-kernel—a 100-per-cent use of the grain, called 100-per-cent extraction. Some people still fail to realize that Graham flour and Graham bread are wheat, perhaps because of the different name and brown color. The so-called "whole-wheat" flour is often 95 per cent of the kernel only, but may be as little as 85 per cent, depending on the amount of the bran and germ removed in the making.

Ordinary white flour contains the endosperm alone, with practically none of the bran and germ. Some brands before the war used up as little as 56 per cent of the wheat, leaving the rest of it to be turned into lower-grade flours and cattle-feed. White flour thus uses less of the wheat for human food than Graham or whole-wheat flour.

Yet to convert all the country's wheat into Graham flour would not be a wheat-saving measure, because it is not so well suited to our trade conditions. Graham flour, for one thing, does not keep so well as flour of lower extractions, as the fat in the germ may become rancid in a comparatively short time. Flour in this country is often thirty days or longer in transit and may be months in warehouses, stores, and homes. A flour to be satisfactory under extreme conditions here or for shipment abroad must keep at least six months—too long to be sure that Graham flour will keep. In small countries like England, where flour is used up more promptly, a high extraction is more practicable than in the United States.

Moreover, while Graham and whole-wheat flours with their larger quantities of mineral salts are a more desirable food for some people than white flour, they are occasionally irritating to people with weak digestions, so that it would be unfortunate to have only these flours on the market.

The Food Administration, therefore, has considered that the most effective use of