This section is from the book "Philadelphia Cook Book: A Manual Of Home Economies", by Sarah Tyson Heston Rorer. Also available from Amazon: Philadelphia Cook Book.
Man has not only to complete and repair the structure which constitutes his body, but has also to create heat in more or less abundance according to the climate in which he lives; consequently to keep the body in a perfectly healthy condition, he must employ a wise combination of food. In perfect health he requires no rules. Nature teaches him how to live. But deviations from the laws of nature, blunt his instincts so that he can hardly tell what nature is, and tempt him, not only to take greater quantities of food than his economy requires, but also of a more stimulating nature. Idleness, want of mental occupation, and self-indulgence often lead to over-feeding, and the immoderate use of alcoholic stimulants.
Food requirements vary with such wide limits in different individuals and different occupations that it is almost impossible to lay down a general rule as to the quantity of food required. In some persons the process of digestion is so rapid that frequent meals are required, and if food is not taken when the digestive organs call for it, a sensation of sickening and faintness comes on and the appetite is lost.
In prisons or in the army, where all men breath the same atmosphere and follow the same occupation, it is possible to establish approximately the amount of food required. In Edinburg, where a hundred prisoners were confined, experiments were made to ascertain the smallest amount of food required to keep the weight and strength of man in idleness. Seventeen ounces of food per day for two months was given each man; four ounces were muscle-making or nitrogenous food; the remaining thirteen ounces heat and force-producing or carbonaceous food. During this time eighteen men lost one and a half pounds each, eighty-two held their own or gained weight. The same experiment was tried in Dundee, but there they gave molasses with their oatmeal instead of milk, as was given at Edinburg. Fifty of their prisoners lost five pounds each, while the remaining fifty held their own or gained weight. By these and other statisties we find that the system requires nearly five times as much carbonaceous as nitrogenous food.
A thorough acquaintance with these facts cannot be too highly estimated. Two-thirds of all the intemperance in the land is due to ill and unscientific feeding. When I say ill-fed, I do not mean the poor who have scanty nourishment, but also that class who indulge their acquired and unnatural appetites in highly seasoned and over-nitrogenous foods. We must keep steadily before us the principle that it is not the quantity of food received which nourishes the body, but the proportion that can be digested of such food, all else is worse than waste, whose presence clogs and throws out of order the delicate digestive organs. A man may eat till he can take no more and still have an unsatisfied feeling. His food has not been properly proportioned. Each organ requires different elements, and each has the power of taking up from the mass such as are required by them and rejecting all others.
While we take food in the proportions to satisfy each organ, peace and harmony prevail in the system, but let us indulge in over or improper feeding, an excitement is at once produced, and each organ makes an effort to reject its enemy, and the whole system becomes "out of order," and still we cannot read this lesson of nature, teaching us to keep out of our stomachs everything but the proper elements. How few there are who know why we serve potatoes or rice with lean beef, why we put butter on our bread, why it is better to eat sugar and cream on oatmeal and grits, why we eat more fruit and less meat in summer than in winter and vice versa.
To nourish ourselves properly, we must bear in mind that during the process of life we use up and cast away matter which must be replaced by equal substances, and we must find these supplies among such substances as contain in them some of our own elements. Albumen must be replaced by albumen, fibrin by fibrin, etc.
For convenience, here, we will divide our food into three classes: nitrogenous, carbonaceous (organic), and the inorganic foods. The nitrogenous foods, as the name indicates, contain nitrogen. They have for their basis albumen, fibrin, gluten and casein. The principal foods of this class are of animal origin, and eggs and milk. They also exist in some vegetables, as gluten and legumen in wheat, lentils and peas. This class contains a large amount of nutriment, of such material as is easily converted into living tissue. These foods are all digested in the stomach, consequently, should not be given in conditions in which this organ needs rest. Belonging to the carbonaceous foods are the starches, sugars and fats. The first two are of vegetable origin, while the latter is produced by vegetables and animals. The chief use of this class is to give heat and force to the body, and constitutes about three-fourths of our food. Consequently, if we wish to develop our muscles, we must eat lean beef (nitrogenous); if we wish to fortify ourselves against cold, we must eat fat. The carbonaceous foods, being fat-formers, should not be taken in larger quantities than the economy requires by persons cor-pulently inclined.
The third class, the inorganic foods - water, salt, phosphate of lime and iron, cannot in themselves support life, yet we could not live without them. Water enters into the composition of all the body's tissues. Salt is found in almost all our natural foods, but not in sufficient quantity to supply the demand of the system. Iron exists in both animal and vegetable foods in sufficient quantity to supply the economy in perfect health. Phosphate of lime is also supplied in both animal and vegetable foods in sufficient quantity when the system is in perfect health; and thus it is seen that each sort of food must fulfill one or more of the body's requirements; and, as a large proportion of the food we consume must be composed of carbon and hydrogen, and is burnt up in the capillary tissues to create heat and force, this class represented by potatoes, rice, oils and sugars must be taken in larger quantities than lean beef, eggs, etc. Bartholow says: "The food supplies to the organism may be so managed as to secure very definite therapeutical results, and by employment of a special and restricted method of feeding, cures may be effected not attainable by medicinal treatment,"