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What is Nutrition?

The following piece was not written by me, but it has guided my practice of clinical nutrition since I first came across it several years ago. I keep a framed copy in the waiting room of my office and have referred many a colleague, friend, and patient to it.

(Source: The American Journal of Clinical Nutrition, May 2003, page 1093. Reprinted from the January-February 1953 issue.)

What Is Nutrition? In an attempt to define the limits of the field which this journal should cover, members of the Editorial Board were asked, in effect: "What is nutrition?"

To the surprise of practically no one, there emerged no boundary line which could be unanimously accepted. The cause lies not in our humble ignorance of so vast a science, but is inherent in the role of nutrition in all life processes. From the cataclysmic union of sperm and ovum, through intrauterine development, through birth, growth, maturity and simultaneous decline and senescence, through disease and injury, until at last vital forces are overcome and all metabolic activity ceases, the processes of nutrition are absolutely essential.

The very functions of life are completely dependent on energy, which in turn is derived from the combustion of foodstuffs. Growth and the unceasing process of repair depend on the utilization of protein and allied nutrients. The life of the individual cell is dependent on oxygen and water; but it is the iron-porphyrin-protein, hemoglobin, which carries the oxygen to the cell, and it is the ultimate breakdown of carbohydrate and interrelated nutrients which, with the fluids we drink, supplies the water. Enzymes and vitamins are the two sides of a coin; ubiquitous minerals come from the earth and from flesh to reach every cell.

As the branch of biology dealing with nutrients—substances ingested and necessary for the proper functioning of the body, nutrition is a large and vital part of all the medical sciences. At once cause and effect, it has no beginning and no end. Without adequate nutrition, there is disease, starvation, and death. With improper amounts or unbalanced combinations of nutrients, there are violent disturbances in every part of the body.

The ramifications of nutrition are universal.

Think of the obstetrician—he is concerned with the nutrition of the fetus through the mother, the anemias of pregnancy, the management of toxemias; the pediatrician—he is greatest role is that of defender of good nutrition and hence of the normal growth and development of the child; the internist—he is preoccupied with nutrition as an essential in the management of the diabetic, hypertensive, cirrhotic, anemic, nephritic, the obese and the lean, the pellagrin, ad infinitum; the surgeon—he pioneered in recognizing the essentiality of fluid balance and nitrogen replacement; yes, and the geriatrician—for he holds out to the elderly the hope of happier years through sane eating. Why, all physicians are involved with nutrition, for it is not the disease that is important, but the person who has the disease—and each person is the product of his nutrition.

No one can foretell what future advances in this old, yet young, science will bring forth. How much closer to realization will be the happier, fuller life when the food supply of all peoples is adequate, when scientific progress, industrial efficiency and common knowledge have built for everyone the very basis of good health—good nutrition.

What is nutrition? It is the cornerstone of preventive medicine, the handmaiden of curative medicine, and the responsibility of every physician.