think nutrition concerns are modern? Read on! Vegetarians may not like this one...How many people, I wonder, ever pause to consider that their bodies are merely machines to do work, furnaces in which necessary fuel is burned, workshops in which worn-out parts are supplied, and store rooms in which fuel and food are laid away for use when needed. Further, like any other piece of apparatus the body works better under certain circumstances: its fires burn better with fuels of certain sorts, mixed in certain proportions and it cannot keep in perfect condition unless furnished with proper materials.
Man thinks he eats because he is hungry; he really eats because his body is crying out for building materials with which to repair the waste that is always going on, and for fuel to keep itself warm—and it is rather "finicky" as to the supply it wants for each of these purposes. At a pinch, it can use almost anything digestible for either, but it groans and complains, and punishes its unfortunate possessor if it is not properly treated.
What the body considers proper treatment is not always that which the palate or the sense of taste considers such. In fact, the palate is the spoiled child of the house; he is always demanding things that are not good for him, and like other spoiled children, the more he is indulged, the more he demands. Sometimes he can make things very unpleasant, for he may refuse to permit any food to pass the portal where he stands on guard, and hence may bring the whole machinery to a standstill. As a rule, however, if treated firmly, he will give in and work for the good of all.
"Savoury" food pleases the palate and causes a greater flow of the various juices and ferments and so promotes digestion. It is therefore a good thing within proper limits, but what the body really needs is "protein" and heat.
"Protein" is a word with which few of us are familiar; we are familiar enough with the thing, however, and it is really impossible to talk about these matters without using one or two scientific words. The lean of meat, the white of eggs, the gluten of wheat are all mostly protein, and we all know how necessary a supply of one or more of these, or of similar things, is to us, if we do not wish to suffer from hunger or from need of nourishment.
While protein can be used for heating, if necessary, its natural use is for repairing purposes, and for this end the body needs one-fourth of a pound a day. Different amounts are required for old and for young, for men and for women, for those living in cold and for those living in hot climates, for laborers and for clerks, but one-fourth of a pound is the right amount for a full-grown man living in a temperate climate and doing moderately active work.
So much for repairing; now for heat. The body, one will say, needs a definite amount of this too. Scientific men have ascertained through countless experiments, the amount necessary for the average man and have found that it is equal to 3,050 "calories" of heat. (Dear me, there goes another unusual word!) A "calorie" is the amount of heat that will raise the temperature of about one pound of water four degrees Fahrenheit. Sugar, starch, and fats are ideal fuels, though protein will burn well, if necessary. Nothing, however, will take the place of protein as a rebuilding material.
What the body needs, then, is a daily supply of one-fourth of a pound of protein and enough sugar, starch, and fat to supply it with 3,050 calories of heat. This is an average for the year, of course. In our climate, the ration, especially the fuel ration, should be varied with the seasons.
True, certain other elements also are needed by the body, but they are required in very minute quantities, and are so widely distributed in nature, that their supply is always assured. On the other hand, any food which supplies protein and fuel in different proportions than these, is not perfect; if it supplies too much heat to the right amount of protein, it is wasteful, if nothing worse; if it supplies too much protein to too little heat, it compels the body to use some of the protein for fuel, which throws an undue strain on the digestion and will probably result in disease sooner or later.
As most of us know, the price of food has little relation to its value to our bodies, however much it may have to our taste. The larger part of the price of the costlier foods is due to their fine appearance, or their pleasant flavor, or their rarity. Tenderloin of beet is less nutritious than shoulder, but it costs more, as you will find out if you go to buy it; and so with many other articles.
Then again, some foods are more digestible than others, as we have all proved again and again, generally when we have eaten something particularly nice. We live, of course, not on what we eat but on what we digest.
During the last eight or ten years, scientific men have been hard at work finding out the facts in regard to all the commoner articles of food; and these facts have been set forth in huge tables of figures that it makes one's head ache merely to look at. They contain some interesting facts, however, if one has the patience to dig them out.
Ordinary white bread, for instance, is about one-third water, one-twelfth protein, and one-half other digestible matters. If all were used as fuel, a pound of bread would supply 1,200 calories; two and a half pounds per day will supply 3,000 calories, about the amount required. If the protein in the bread be used for its usual purpose of rebuilding, leaving the other digestible substances for fuel, three pounds of bread would furnish just a trifle more of both fuel and protein than is required in a temperate climate by a man doing moderately active muscular work. Bread alone, then, is theoretically very nearly a perfect or "balanced" diet—though three loaves a day would certainly stir that bad boy, the palate, to rebellion.
If a man lived on bread alone he would eat, in a lifetime of seventy years, about 75,000 pounds; or say, he would devour a loaf 30 feet high by 10 feet square, which would cost him about $4,000.
But living wholly on lean meat would be a good deal worse than living wholly on bread. To do this, a man would have to eat three and one-half pounds a day to supply himself with needed food, and would not thrive then as he would on bread. One and a half pounds of meat would supply him all the protein needed, but would yield, in addition, only about one thousand calories of heat. To make up the balance, two pounds more of meat must be eaten, all of it for fuel. Meat is a very poor fuel, and to burn two pounds of it a day would throw a heavy strain on the digestion and probably lead to disease. Fancy eating three and a half pounds of meat a day!
Living on lean meat alone, a man would eat, in seventy years, an ox about thirty-five feet long, fifteen feet high and twelve feet thick, supposing it to consist of solid meat without bones. This would weigh about 90,000 pounds and cost about $15,000.
Thus, bread alone worries the palate and is in time refused; meat alone furnishes too much protein and not enough heat; candy, pastry, and the like supply too much heat, which must be laid away in fat in the body's storehouse or be worked off in nervous energy. No one of the three is good without the others.
On the other hand, a mixed diet makes things a great deal better all around. One pound of bread, one and one-third pounds of lean meat, and one-sixth of a pound of butter daily would supply almost the exact ideal proportions. In seventy years, this would run to 25,000 pounds of bread, 33,000 pounds of meat and 4,000 pounds of butter—62,000 pounds in all, costing, say, $9,000.
If a man lived wholly on fish, he would require eleven pounds a day, or 275,000 pounds in a lifetime—say, a fish 70 feet long by 30 deep by 10 thick. If he lived on rice alone, he would have to eat three pounds a day, or 75,000 pounds in a lifetime—an amount which would furnish him with about 50 per cent, more heat than he had any use for. By combining fish and rice, however, as the Chinese do, in the proportion of one pound of the former and two of the latter, he could live very well. The relative cost in this country would be about $30,000 for fish alone, and $6,000 for rice alone. The two combined would, of course, cost much less than the fish alone.
His hardest time, however, would be when he tried to live on green vegetables or fruits alone, avoiding bread and beans, both of which play such a part in vegetarian bills of fare. Of ordinary vegetables, such as beets, cabbages, tomatoes, and the like, he would have to eat 20 pounds daily. Of fruits, he would have to eat 30 pounds daily, and even of potatoes, 15 pounds.
On the other hand, two pounds of rye bread, two pounds of potatoes, and a taste of fat, either animal, or vegetable, make a very cheap, well-balanced ration, costing only about $1,500 in a lifetime. Thousands of Russian peasants live on just such a diet.
As I said before, all these estimates are for a man doing moderately active muscular work in a temperate climate. A man doing hard muscular work requires about one-fifth more and a man in an office about one-fifth less. Boys require only one-half as much at six years of age and nine-tenths as much at sixteen. Women generally require one-fifth less than men of equal activity.