GOOD FOOD AT REASONABLE COST.

BY C. F. LANGWORTHY, PH. D.

Expert in Nutrition, Office of Experiment Stations, U. S. Department

of Agriculture.

The human body needs food, air, and water for its growth and maintenance just as do all living things. An engine can not run a machine or draw a train unless it has fuel, which is converted into energy or, as we say, which is used to generate power. In the same way the body must have fuel for the work of all sorts which it performs, for instance, for the work expended by a mason in laying stone, or by a carpenter in sawing or driving nails, by a woman who sweeps or does her housework, or by a child who runs or plays, and the body must also have fuel for the work which goes on inside it, such as the beating of the heart, or the movement of the chest when we breathe, a sort of work which is less often thought about and so less familiar to most of us.

Everyone knows that a large engine requires more fuel than a small one and that if the work is severe more fuel is needed than is the case when the engine is simply running and little or no work is done. It is the same way with the human body. A large vigorous man needs more food than a small child or a woman who is not more than twothirds his size, and if a man or woman is engaged in severe work each needs more food than when idle, the need being manifested by "a better appetite." Age also has a decided effect on the kind and amount of food needed, an aged man or woman naturally requiring less food than a man in youth or middle life, since the daily tasks and the amount of work done gradually decrease until in extreme old age most of the time is passed in quiet. Soft foods and simple dishes are more suited to old age when teeth are few and body vigor is much less than in the prime of life than are the hearty foods which strong men and women need. The infant needs the mother's milk and later the simple foods-eggs, milk, bread, vegetables, cereals, fruits, etc., which are the best foods for childhood and are most certain to build up a vigorous body. As childhood passes, the mixed diet with which most of us are familiar is commonly followed and, all things considered, is doubtless the most satisfactory for ordinary persons in health. Such a diet is made up of vegetables, fruits, flour and other products from cereal grains, meat, fish, dairy products, eggs, and so on.

Many persons have an idea that there is some special food, some ideal

diet suited to each kind of work and to every condition of life and that if we possessed full knowledge of the subject it would be desirable to prescribe the daily fare with the same care and accuracy with which a physician prescribes his medicines, but this does not seem to be the case. We do not regulate with such exactness the work we do, the leisure we take, the amount of clothing we wear, and all other conditions of our daily lives, and so it is for our best interest simply to regulate our diet along general lines in accordance with good sense, economy, and the knowledge which has been gained from a scientific study of the subject, taking care that the different foods are so combined that all the needs of the body are provided for, that excessive waste is prevented, and that both undernourishment and excess or overeating are avoided.

It is essential that foods should be of good quality, clean and wholesome, and that they should be well cooked. The dishes that are most relished and the methods of preparing them will vary in different countries and in different regions of the same country, for each race, and indeed each region, has its favorite foods and its special methods of cookery. However, when the question of food is carefully studied we find that value of the diet expressed in scientific terms is practically the same the world over when we consider persons of like size and weight performing equal amounts of work. This means that just as an engine of a given size would require in China the same amount of fuel for a given work which would be needed in the United States, so the human machine in any part of the world requires the same amount of fuel, that is, food, for a given task which would be required in any other region.

With the engine it is immaterial whether the fuel be wood, coal, or anything else which is convenient provided the quality is satisfactory and the engineer knows how to use it. With the human machine it is something the same. All ordinary foods are useful when rightly combined and each country will naturally make use of the food supply which may be most easily and economically produced.

A study of the various materials which are used as food shows that they are composed of comparatively few constituents, namely, water, mineral matter, starch, sugar, and other bodies which are called carbohydrates, fat, and nitrogenous material commonly called protein, such as the white of egg and the lean of meat. The human body is made up of the same constituents. All of the body tissues contain the nitrogenous material, protein, which is similar to that found in the lean of meat, the white of egg, in gluten of wheat, etc., and so it is understandable that the body must be supplied with food containing nitrogenous material

enough for forming this tissue and for replacing any which, like the skin, finger nails, etc., may be worn away by the various conditions of our daily life and also for other purposes for which the body requires protein. In the case of the infant the nitrogenous material needed for body growth is supplied by the milk-a food comparatively rich in this constituent as well as in the other nutrients. Later in life the nitrogenus material is supplied largely by milk, cheese, eggs, meat, cereals, beans and similar foods.

As has been said, men, the world over, of like size and performing like amounts of work apparently eat practically the same amounts of food when considered from the standpoint of its composition, and students of nutrition questions are very generally of the opinion that this fact is more than a coincidence and that these average quantities eaten actually represent average needs. Values deduced from such observations are commonly referred to as dietary standards, that is, guides for food management.

Expressed in its simplest terms, the dietary standard for a man of medium size, say 150 pounds in weight, in good health and performing a moderate amount of work, calls for 100 grams (or 3.5 ounces) of nitrogenous material (protein), and fat and carbohydrates enough to supply with the protein 3,500 calories of energy in the amount of food provided per day. There is always some waste in cooking and serving food and if we consider the food purchased the values are 115 grams protein (4) ounces) and 3,800 calories. These terms are unfamiliar to most persons and it is unfortunate that some terms which are more familiar can not be found, but it is true here as everywhere else that each subject requires its own terms. We can measure cloth by the yard or milk by the quart, but we must measure work by horsepower or electricity by terms which are even less familiar. Fortunately, in the case of food and diet the matter can be explained in other ways so that the results can be applied in home management without undue difficulty.

The housekeeper who wishes to estimate the nutritive value of the food she prepares, in order that she may conform with the suggested dietary standards, can readily do so by the use of such a table as the one here given, which shows the protein and energy value of the portions ordinarily served of the more common food materials, the values given being approximately only as it would be hardly desirable to state absolute figures for such a purpose as that for which the table is designed.

The weights of the food portions included in the table are given in both grams, the unit of weight commonly used in scientific work, and in ounces, the more common household unit. To avoid unusual fractions

of an ounce the nearest 1⁄2 ounce or 4 ounce or some similar common fraction is used instead of more accurate equivalents.

In such a table the protein content of the food gives an idea of its relative value for building body tissue. The value of the food as a source of power for carrying on work is expresed by the energy it supplies when utilized in the body as fuel is burned under a boiler, and is measured as calories. A calorie is equal very nearly to 1.54 foot-ton, that is, it represents force which would be sufficient to lift one ton 1.54 feet and is a more convenient unit for such purposes than horsepower or other similar unit.

APPROXIMATE WEIGHT AND NUTRITIVE VALUE OF AN AVERAGE PORTION OF SOME COMMON FOODS.

The table may be conveniently used by supposing that the food eaten by one member of the family will represent in character and amount the food for the entire family. To estimate by means of the table the food value of the diet the portions of each article used at each meal should be set down in order, together with the protein and energy which each supplies and the total sum of the protein and of the energy will represent the amount eaten in the whole day.

Suppose, for instance, that breakfast for the man of the family, a mechanic whose work calls for a medium expenditure of physical strength, consists of two slices of bread, one portion of butter, a potato, two cups of coffee and two eggs. Each slice of bread, as the table shows, supplies 4 grams protein and 175 calories. Two slices would therefore supply 8 grams protein and 350 calories. A portion of butter supplies 95 calories of energy. Butter, as will be noted, contains no protein. One potato would supply 4 grams of protein and 145 calories; two eggs 14 grams protein and 192 calories. Tea and coffee in themselves supply so little nutritive material that they may be neglected. The sugar and cream, however, which would be used should be taken into account. If in each cup of coffee a teaspoonful of sugar is used the amount for two cups would of course be two teaspoonfuls and the energy value 80 calories. As the table shows, sugar contains no protein. When 14 gill of cream is used for each cup of coffee 1⁄2 gill will be used for two cups and according to the figures in the table would supply 2 grams protein and 130 calories. If these foods eaten at breakfast and the protein and energy which they supply are set down in order and the quantities added together, the total shows the amount eaten for breakfast as follows:

FOOD VALUE OF BREAKFAST.

In the day's ration which has been selected we will suppose that the man carries his lunch and that it consists of two sandwiches (made from four slices of bread, one portion of butter and two portions of cheese), a slice of cake and a banana, and that for dinner he has one