Nutritional Notes

                NUTRITION, briefly stated, is the process whereby ingestion and digestion of the foods necessary for the maintenance of life is accomplished. Dietetics is the study of nutrition. In the study of dietetics, it is necessary to consider in addition to foods, anatomy, physiology, chemistry, psychology, and many other sciences. Nutrition and dietetics is of first importance in the building and maintenance of dental and physical health.

The human body contains approximately seven pound of mineral matter. Minerals in the body are stored chiefly in the bones and teeth. The body requirements demand eight important minerals, and others in small amounts. The eight are: phosphorus, sulphur, potassium, sodium, calcium, magnesium, chlorine and iron. Aside from building the skeletal structure, minerals are needed for the processes that provide energy. Muscles need calcium, potassium, and phosphorus for contraction. The blood needs iron for hemoglobin. The thyroid gland requires iodine for thyroxilin, the controller of metabolism. In a balanced diet, sufficient minerals are provided. However foods vary in their mineral content. The mineral in meat varies according to the quality of the pasturage of the animal. Vegetation varies in mineral content according to the soil.

Next to oxygen, water is the most importantnutritional requirement. Water conveys all nutrients to the cells and carries away the wasted products of metabolism. Water exists in all the body tissues. Deprived of water, man will die in sixty to seventy hours. Abstinence from food may continue a month or more without death. Water is absorbed into the body through the small and large intestine, not from the stomach. It is eliminated through the kidneys, lungs, skin and bowels. The evaporation of water through the lungs and skin is the chief factor in the regulation of the body temperature.

The particular adaptability of animals to types of foods is reflected in their alimentary tract. In man, the length of the alimentary tract is five times his body length, horse thirteen times, camel sixteen times, sheep thirty times, and the cat only four times. The intestinal capacity of man is fourteen quarts, horse 220 quarts, ox 360 quarts, dog seven quarts, and the cat one quart. This indicates that man is intended to subsist partly on a diet of fish and meat.

Butter, cream and fish liver oils should be substituted for fats by those who find an intolerance to this dietary factor. Lard, bacon and vegetable oils only aggravate the condition. Fruits and carbohydrates aid the digestion of fats by burning them in the process of oxidation. Fats are an essential part of the dietary and aid materially in producing body heat.

The cheapest and most abundant form of food is carbohydrate. Carbohydrates are the energy and heat forming foods. They are fattening, only if the person does not take the necessary exercise to utilize the energy and heat produced. People doing manual labor or exercising strenuously, find carbohydrates a necessity.

Fish is similar in nutritive value to meat. In the northern countries fish is the most popular of all foods. In this country fish is daily becoming more used. The rich source of minerals and vitamins in fish have made them an important factor in the dietary.

Stimulants have a questionable place in the dietary. They act on the nervous system, to produce a mild irritation. This is followed by a period of depression. The use of stimulants to relieve depression becomes a habit, and their effect is readily lost.

There are five reasons for eating fats. In the intestines fats are converted into soaps, and this lubricating action aids elimination, prevents constipation, and hastens absorption of foods. Fats are a concentrated food and reduce the general bulk of the diet. Certain fats are rich in Vitamins A and D, and should be selected for this factor. The calorific value of fats is twice that of an equal amount of carbohydrates or protein. Fat is readily stored in the body and can be later utilized to advantage.

In consideration of eggs as a food, it must be remembered that an egg is an undeveloped chicken and as such must contain all the food requirements for the formation of living matter. It is therefore readily seen that the egg contains protein, carbohydrate, fat and minerals in quantities sufficient for the development of the chick. The white of an egg contains protein (12.6%), water (85.7%), mineral matter (0.59%) and fat (0.25%). The yolk contains protein (16.2%), water (50.9%), mineral matter (1.09%), and fat (31.75%). Digestibility of the egg depends largely upon the form in which it is taken. A lightly boiled egg is more easily digested than a raw egg. A finely chopped hardboiled egg is digested almost as easily as a soft boiled egg. Eggs are easily absorbed and leave little residue.

Because of the abundant supply of minerals in milk, it is a most important requisite in the dietary from a dental standpoint. McLester and McCollum discuss in a convincing manner, “the superior physical development and greater stamina of pastoral peoples who live largely on milk and milk products.”

In a large part of the experimental work that has been done on nutrition and dietetics, animals have been used. One group of animals are usually fed a normal diet, this is called the control group. Another group is placed on a special feeding, sometimes one element is taken from the diet, other times one food factor is increased and the comparison between the control group and the experimental group furnishes evidence that has been of great value in determining the effect of certain food elements. It is of course not proven until the same effect has been produced in humans.