body.

There is no question as to the value of health either from the standpoint of comfort or of economy. And the knowledge which will enable one to spread the good work intelligently cannot but raise the standards of living throughout the entire community.

In taking up the study of dietetics, the student is introduced to some of the fundamental principles governing the health and well-being of a people, since dietetics includes a study of food and its relation to the body.

The relationship between right food and good health is very close; how close is being demonstrated constantly in experimental fields of scientific research.

To be able to judge whether the food one eats daily is giving the best possible value from a physiological and economic standpoint, requires a definite knowledge of food, its source, composition and nutrient value, as well as its relation to the body in health and disease.

No one is capable of giving constructive advice upon matters pertaining to diet, unless he has acquired this knowledge through training. A nurse should obtain this training during her course in the hospital, through the class room, the wards and the diet kitchen.

The dividing line between health and disease is frequently almost imperceptible, and without a knowledge of the normal body, it is, at times, impossible to tell where the normal leaves off and the abnormal begins. For this reason a nurse must understand normal nutrition, that is, the behavior of food in the healthy body, before undertaking the task of ministering to the body attacked by disease.

In a text of this kind, it is impossible to cover all phases of the subject, especially since day by day new discoveries are being made with relation to food and its uses in the body. But with careful attention to the principles set forth, a nurse should be able to carry out the dietary orders given her by the physician and dietitian in the hospital. And, when her course of training is finished, she should find herself equipped to assist in raising the standard of health through her knowledge of dietetics. With this brief summary of the aims and object of the study of dietetics, we will begin the actual work with a study of Food.

Food Materials.—Food is the name given to any substance which, taken into the body, is capable of performing one or more of the following functions:

For the convenience of study scientists have arranged the foodstuffs in groups:

All foods are composed of certain chemical elements; namely, carbon, oxygen, hydrogen, nitrogen, sulphur, phosphorus, iron, magnesium, potassium, chlorine, sodium, calcium, with traces of various others. The manner in which these elements are combined and the amounts in which they occur determine the group to which the combination belongs, and give to the foodstuff its characteristic position in human nutrition.

COMPOSITION OF THE FOODSTUFFS

The chemical elements are combined in food and in the body, as: (a) carbohydrates, composed of carbon, oxygen and hydrogen; (b) fats, composed of carbon, oxygen and hydrogen; (c) proteins, composed of carbon, oxygen, hydrogen, nitrogen and sulphur; (d) water, composed of hydrogen and oxygen; (e) mineral salts. The first three foodstuffs constitute the Organic Food group. The last two include the remaining chemical elements, calcium, phosphorus, sodium, potassium, chlorine, magnesium, iron and traces of others which make up the Inorganic Food group.

Each of the foodstuffs belonging to the organic group is capable of being burned in the body to produce heat for: (a) the maintenance of the body temperature; (b) internal and external work.

Neither water nor mineral salts alone can be burned to produce heat; nevertheless, they enter into the composition and take part in every function performed by the carbohydrates, fats and proteins; therefore one foodstuff cannot be said to be of greater importance than another, since the needs of nature are best met by a judicious combination of all. However, the wear and tear of life can be more efficiently accounted for, and the strain upon the organism reduced more nearly to a minimum when the various foodstuffs are furnished in amounts which science is proving to be necessary for the health and well-being of the organism.

The sixth essential food substance, the Vitamines, together with the adjustment of the five foodstuffs just mentioned—the amounts and types of each in the dietary which will assure the body of the best results—has been, and still is a subject of grave interest. Even on the most perfect adjustment of these foodstuffs, the diet would fail to give the desired results without the inclusion of the sixth, or vitamine factor, which has proved to be essential for the growth and development of the normal body, as well as for its protection against certain deficiency diseases.

In order to obtain the best results from food, both from a health and an economic standpoint, it is necessary to become familiar with the foodstuffs as they are combined to make up the various common food materials. One foodstuff may be a producer of heat, but may lack certain chemical elements which are essential to the building of tissues; another may be able to accomplish both functions in the body, but will prove too expensive to use as fuel, except when it is absolutely necessary to do so. Thus, it is essential for the nurse to understand where and how both the foodstuffs and the vitamines occur in nature, in order to make use of them more advantageously. The following table gives the sources of the foodstuffs, after which a description of the individual foodstuffs and vitamine factors will serve to point the way to their use in the dietary: