1 The most usable list of these portions is to be found in the appendix of Feeding the Family, by Mary Swartz Rose. (Macmillan, 1917.)

100-calorie portions

A sufficient diet

In order to find actual figures to state the body's requirements, studies were made in two ways. The first, known as the statistical method, was a study of the actual food consumed by groups of people living a normal life and performing the same type of work. Many of these studies have been made all over the world. The other one, known as the experimental method, was a study of the actual food requirements of different individuals living under different conditions. This required an elaborate apparatus known as the respiration calorimeter by which it was possible to measure under fixed conditions the amount of energy given off from the body in the form of work and heat. The results obtained from both of these methods showed that the food required varies directly with the amount of energy expended; that is, the man digging a ditch in the street and the lumberman at work in the Maine woods require far more food than a man who sits at his desk all day, or even than the man who stands behind the counter day after day. Food requirements were also found to vary with the age of the individual, the sex, the body weight, and the mode of life. Growing boys and girls, particularly between the ages of fourteen and twenty, were found to require actually more food than their fathers and mothers, though their body weight was less. As the individual grows older, the life processes slow down and not so much food is required. With these points in mind, certain definite standards on a twenty-four hour basis have been adopted for different occupations as follows:

Dietary standards

Mode of Life

Women (Calories)

Men (Calories)

Those who sit at their work.................

2000

2500

Those who stand at their work . . . . . . . . .

2400

3000

Those who use back muscles at their work..

2800

3500-6000

It might be of interest to note that the United States Army active service ration is 4500 calories, and that at one of our big boys' schools, the boys were eating 5000 calories a day. The average amount needed by a woman doing her own housework is 2400 to 2500 calories a day. The days she does the washing or hard scrubbing, she should eat more than on other days, and she should not allow herself to become so tired that she cannot eat at all. This can be prevented by taking a glass of milk with bread and butter in the middle of the morning before she gets too tired to eat her dinner.

When speaking of food requirements, we must take into consideration other things besides the fuel value of the food itself. According to our definition of food, the providing of energy and heat is only half of the work done by foods. The other half is the providing of the actual material out of which the body is built; that is, our bodies are far more wonderful than any man-made machine. If an automobile bursts a tire or loses an important nut, no amount of gasoline burned in the engine will mend the tire or will replace the nut. If, however, a child breaks an arm or has a cut finger, all that the doctor does is to set the bone straight, or make sure that there is no dirt in the cut. The healing process in both cases is carried on entirely by the body itself. The blood brings to the injured tissue those elements which are necessary to make new tissue.

Need for building material

The building material needed by the body and to be supplied by the food has already been spoken of, but we will review it rapidly here. The most important is nitrogen, which is provided in all protein foods and is required for different tissues. It is thought that different proteins provide building material for different tissues. Some of the proteins in our foods are better than others for muscle-building material, and so we have what are known as complete and incomplete proteins. Gelatine belongs to this latter class of proteins. Since the value of protein foods varies in this way, it is well to use a variety of protein foods and not to rely upon a single food for the sole source of nitrogenous material in the body.

The quantity of protein absolutely required by each man in twenty-four hours has been under discussion for some years. Dr. Atwater felt that 125 grams was not too much. In recent years, however, it has been found possible to maintain bodily health on a smaller quantity, from 80 to 90 grams. With war conditions, the protein content of the diet was very greatly reduced in some countries, especially in Belgium and

Protein needed

Germany. What effect this will have on the future health of the nation time alone will show, although figures are already coming in which indicate a great loss of power to resist disease, an increase in tuberculosis, and a greatly increased death-rate. A recent newspaper report from Russia indicated that it is thought the great increase in the number of babies which are born blind is due to the under-nourished condition of the mothers.

If the diet of an adult contains from 2 1/2 to 3 ounces of protein foods in a day, it is thought that sufficient nitrogen will be provided the body for all ordinary requirements. Convalescents, who need more building material, should have slightly more, and care should be taken that growing children should have, not more protein foods necessarily, but that the protein should be of the best type, such as is found in milk and eggs. In order to help the housekeeper figure out how much protein the family are getting, a table of half-ounce protein portions has been devised.1 This must not be confused with the one hundred calorie portion, since that gives total fuel value, while this gives the amount of food which would contain approximately one half ounce of protein. These are as follows:

One half Ounce Protein Portions

Milk, whole or skimmed, 1 pint

Eggs, 2

Cottage cheese, 1/4 cup, or 2 ounces

American cheese, 1 1/4 inch cube, or 2 ounces

Peanuts, shelled, 2 ounces

1 This table and the following ones are taken from Food and the War, published by the United States Food Administration, 1918.

Lean meat, without bone, 2 1/4 ounces, or a piece 2 x 2 x 3/4 in. Fish, a similar piece Beans, dried, cooked, 1 1/2 cups Cereal, cooked, 2 1/3 to 3 cups Bread, 6 slices, 3 1/2 X 3X 1/2 in.

In order to get two and a half to three ounces of protein a day, five or six of these portions should be included in the course of the day's meals.

Sulphur and phosphorus are both essential ingredi-ents of all body protein, and occur in foods wherever nitrogen is found. Phosphorus is also found in other foods, so that if the protein content of our food is sufficient, these will be also.

The body must also have certain mineral salts in order to keep it in good condition. The iron needed by the blood and entering into the structure of all active cells is found in egg-yolks, green vegetables, especially spinach, and meats. It is thought that 15 milligrams of iron are required daily. Social workers find that among the poor the diet is apt to lack iron more than any other constituent. The following list shows por-tions of food each of which contains approximately two milligrams of iron, so that seven and a half of these portions should be used daily:

Portions containing Two Milligrams Iron

White flour, 200 grams, enough for 3/4 pound bread

Graham flour, 40 grams, or 2 medium slices of bread

Egg-yolk, 22 grams, or from 1 1/2 to 2 eggs

Lean meat, 50 grams, about 2 ounces

Spinach, raw, 2 ounces, cooked, about 1/3 cup

String beans, a little over 1/3 pound, about 1 1/4 cups

Other sub-stances needed

Potato, 1 good-sized

Sweet potato, almost 1 pound

Oranges, 4 large

Milk, 810 grams, almost 1 quart

Another mineral which is very important for the growth of bones and teeth is calcium. The chief source of calcium in the diet is milk but it is also found to some extent in other foods. The body's daily requirement for calcium is 0.67 gram. This is found in the following foods:

Portions containing Total Calcium Requirement for One Day

Milk, less than 1 1/4 pints Cheese, 2 1/2 ounces White flour, over 7 pounds Beef, 21 pounds Turnips, 2 1/3 pounds Carrots, 2 1/2 pounds

The other chemical elements necessary for the proper health and growth of the body are found in fruits and green vegetables; so also are the "vitamine" substances essential for growth. If this class of foods is well represented in the diet, together with a variety of other foods, all these substances will be provided in sufficient amounts.