WHAT KIND OF FOOD SHOULD WE EAT?
Generally speaking, our Appet.i.tes will Guide us. Our whole body is an ingenious machine for catching food, digesting it, and turning the energy, or fuel value, which it contains, into life, movement, and growth.
Naturally, two things follow: first, that the kind and amount of food which we eat is of great importance; and second, that from the millions of years of experience that the human body has had in trying all sorts of foods, it has adapted itself to certain kinds of food and developed certain likes and dislikes which we call _appet.i.tes_. Those who happened to like unhealthy and unwholesome foods were poisoned, or grew thin and weak and died off, so that we are descended solely from people who had sound and reliable food appet.i.tes; and, in the main, what our instincts and appet.i.tes tell us about food is to be depended upon.
The main questions which we have to consider are: How much of the different kinds of food it is best for us to eat, and in what proportions we should use them. Both men and animals, since the world began, have been trying to eat and digest almost everything that they could get into their mouths. And what we now like and prepare as foods are the things which have stood the test, and proved themselves able to yield strength and nourishment to the body. So practically every food that comes upon our tables has some kind of real food value, or it wouldn"t appear there.
The most careful study and a.n.a.lysis have shown that almost every known food has some peculiar advantage, such as digestibility, or cheapness, or pleasant taste as flavoring for other more nutritious, but less interesting, foods. But some foods have much higher degrees of nutritiousness or digestibility or wholesomeness than others; so that our problem is to pick out from a number of foods that "taste good" to us, those which are the most nutritious, the most digestible, and the most wholesome, and to see that we get plenty of them. It is not that certain foods, or cla.s.ses of food, are "good," and should be eaten to the exclusion of all others; nor that certain foods, or cla.s.ses of food, are "bad," and should be excluded from our tables entirely; but that certain foods are more nutritious, or more wholesome, than others; and that it is best to see that we get plenty of the former before indulging our appet.i.tes upon the latter.
Beware of Tainted Food. The most dangerous fault that any food can have is that it shall be tainted, or spoiled, or smell bad. Spoiling, or tainting, means that the food has become infected by some germs of putrefaction, generally _bacteria_ or _moulds_ (see chapter XXVI). It is the poisons--called _ptomaines_, or _toxins_--produced by these germs which cause the serious disturbances in the stomach, and not either the amount or the kind of food itself. Even a regular "gorge" upon early apples or watermelon or cake or ice cream will not give you half so bad, nor so dangerous, colic as one little piece of tainted meat or fish or egg, or one cupful of dirty milk, or a single helping of cabbage or tomatoes that have begun to spoil, or of jam made out of spoiled berries or other fruit. This spoiling can be prevented by strict cleanliness in handling foods, especially milk, meat, and fruit; by keeping foods screened from dust and flies; and by keeping them cool with ice in summer time, thus checking the growth of these "spoiling" germs. The refrigerator in the kitchen prevents colic or diarrhea, ice in hot weather is one of the necessaries of life. Smell every piece of food to be eaten, in the kitchen before it is cooked, if possible; but if not, at the table avoid everything that has an unpleasant odor, or tastes queer, and you will avoid two-thirds of the colic, diarrhea, and bilious attacks which are so often supposed to be due to eating too much.
[Ill.u.s.tration: A CHEAP HOME-MADE ICE BOX
This should not cost over twenty-five cents. The sketch shows an ordinary soap box; inside is a tin pail surrounded by a sheet of tin, so that there is a circular air s.p.a.ce between the pail and the sheet of tin. Sawdust is packed around the tin, and cracked ice (two cents a day) fills the tin pail around the milk bottle. The newspapers inside the cover help to keep out the warmth of the outside air. Recommended by the Boards of Health of New York City and Chicago.]
Variety in Food is Necessary. Man has always lived on, and apparently required, a great variety of foods, animal and vegetable--fish and flesh, nuts, fruit, grains, fat, sugar, and vegetables. Indeed, it was probably because man could live on anything and everything that he was able to survive in famines and to get so far ahead of all other sorts of animals.
We still need a great variety of different sorts of food in order to keep our health; so our tendency to become tired of a certain food, after we have had it over and over and over again, for breakfast, dinner, and supper, is a sound and healthy one. There is no "best food"; nor is there any one food on which we can live and work, as an engine will work all its "life" on one kind of coal, wood, or oil. No one kind of food contains all the stuffs that our body is made of and needs, in exactly the right proportions. It takes a dozen or more different kinds of food to supply these, and the body picks out what it wants, and throws away the remainder.
Even the best and most nutritious and digestible single food, like meat, or bread and b.u.t.ter, or sugar, is not sufficient by itself; nor will it do for every meal in the day, or every day in the week. We must eat other things with it; and we must from time to time change it for something which may even be not quite so nutritious, in order to give our body the opportunity to select from a great variety of foods the particular things which its wonderful instincts and skill can use to build it up and keep it healthy. This is why every grocery store, every butcher shop, every fish market, and every confectioner"s shows such a great variety of different kinds of foods put up and prepared in all sorts of ways. Although nearly two-thirds of the actual fuel which we put into our body-boilers is in the form of a dozen or fifteen great staple foods, like bread, meat, b.u.t.ter, sugar, eggs, milk, potatoes, and fish, yet all the lighter foods, also, are needed for perfect health.
It is possible, by careful selection, and by taking a great deal of trouble, to supply all the elements of the body from animal foods alone, or from vegetable foods alone. But practically, it has everywhere, and in all ages, been found that the best and most healthful diet is a proper combination of animal and vegetable foods. Our starches, for instance, which furnish most of our fuel,--though they give us _comparatively little_ to _build up_, or _repair_, the body with,--are found, as we have seen, in the vegetable kingdom, in grains and fruits; while most of our proteins and fats, which chiefly give us the materials with which to build up, or repair, the body, are found in the animal kingdom. There is no advantage whatever in trying to exclude either animal food or vegetable food from our dietary. Both animal and vegetable foods are wholesome in their proper place, and their proper place is on the table together.
Those nations which live solely, or even chiefly, upon one or two kinds of staple foods, such as rice, potatoes, corn-meal, or yams, do so solely because they are too poor to afford other kinds of food, or too lazy, or too uncivilized, to get them; and instead of being healthier and longer-lived than civilized races, they are much more subject to disease and live only about half as long.
THE THREE GREAT CLa.s.sES OF FOOD-FUEL
Food is Fuel. Now what is the chief quality which makes one kind of food preferable to another? As our body machine runs entirely upon the energy or "strength" which it gets out of its food, _a good food must have plenty of fuel value_; that is to say, it must be capable of burning and giving off heat and steaming-power. Other things being equal, the more it has of this fuel value, the more desirable and valuable it will be as a food.
From this point of view, foods may be roughly cla.s.sified, after the fashion of the materials needed to build a fire in a grate or stove, as Coal foods, Kindling foods, and Paper foods. Although coal, kindling, and paper are of very different fuel values, they are all necessary to start the fire in the grate and to keep it burning properly. Moreover, any one of them would keep a fire going alone, after a fashion, provided that you had a grate or furnace large enough to burn it in, and could shovel it in fast enough; and the same is true, to a certain degree, of the foods in the body.
How to Judge the Fuel Value of Foods. One of the best ways of roughly determining whether a given food belongs in the Coal, the Kindling, or the Paper cla.s.s, is to take a handful or spoonful of it, dry it thoroughly by some means,--evaporating, or driving off the water,--and then throw what is left into a fire and see how it will burn. A piece of beef, for instance, would shrink a good deal in drying; but about one-third of it would be left, and this dried beef would burn quite briskly and would last for some time in the fire. A piece of bread of the same size would not shrink so much, but would lose about the same proportion of its weight; and it also would burn with a clear, hot flame, though not quite so long as the beef. A piece of fat of the same size would shrink very little in drying and would burn with a bright, hot flame, nearly twice as long as either the beef or the bread. These would all be cla.s.sed as Coal foods.
Then if we were to dry a slice of apple, it would shrink down into a little leathery shaving; and this, when thrown into the fire, would burn with a smudgy kind of flame, give off very little heat, and soon smoulder away. A piece of raw potato of the same size would shrink even more, but would give a hotter and cleaner flame. A leaf of cabbage, or a piece of beet-root, or four or five large strawberries would shrivel away in the drying almost to nothing and, if thoroughly dried, would disappear in a flash when thrown on the fire. These, then, except the potato, we should regard as Kindling foods.
But it would take a large handful of lettuce leaves, or a big cup of beef-tea, or a good-sized bowl of soup, or a big cuc.u.mber, or a gallon of tea or coffee, to leave sufficient solid remains when completely dried, to make more than a flash when thrown into the fire. These, then, are Paper foods, with little fuel value.
CHAPTER IV
THE COAL FOODS
Kinds of Coal Foods. There are many different kinds of Coal foods, such as pork, mutton, beef, bread, corn-cakes, bacon, potatoes, rice, sugar, cheese, b.u.t.ter, and so on. But when you come to look at them more closely, and to take them to pieces, or, as we say, a.n.a.lyze them, you will see that they all fall into three different kinds or cla.s.ses: (1) _Proteins_, such as meat, milk, fish, eggs, cheese, etc. (2) _Starch-sugars_ (_carbohydrates_), found pure as laundry starch and as white sugar; also found, as starch, making up the bulk of wheat and other grains, and of potatoes, rice, peas; also found, as sugar, in honey, beet-roots, sugar cane, and the sap of maple trees. (3) _Fats_, found in fat meats, b.u.t.ter, oil, nuts, beeswax, etc.
This whole cla.s.s of Coal foods can be recognized by the fact that usually some one of them will form the staple, or main dish, of almost any regular meal, which is generally a combination of all three cla.s.ses--a protein in the shape of meat; a starch-sugar in the form of bread, potatoes, or rice; and a fat in the form of b.u.t.ter in northern climates, or of olive oil in the tropics.
PROTEINS, OR "MEATS"
Proteins, the "First Foods." There are proteins, or "meats," both animal and vegetable; and no one can support life without protein in some form. This is because proteins alone contain sufficient amounts of the great element called _nitrogen_, which forms a large part of every portion of our bodies. This is why they are called proteins, meaning "first foods," or most necessary foods. Whatever we may live on in later life, we all began on a diet of liquid meat (milk), and could have survived and grown up on nothing else.
Composition of Proteins. Nearly all our meats are the muscle of different sorts of animals, made of a soft, reddish, animal pulp called _myosin_; the other princ.i.p.al proteins being white of egg, curd of milk, and a gummy, whitish-gray substance called _gluten_, found in wheat flour. This gluten is the stuff that makes the paste and dough of wheat flour sticky, so that you can paste things together with it; while that made from corn meal or oatmeal will fall to pieces when you take it up.
The jelly-like or pulp-like myosin in meat is held together by strings or threads of tough, fibrous stuff; and the more there is of this fibrous material in a particular piece or "cut," of meat, the tougher and less juicy it is. The thick, soft muscles, which lie close under the backbone in the small of the back, in all animals, have less of this tough and indigestible fibrous stuff in them, and cuts across them give us the well-known porter-house, sirloin, or tenderloin steaks, and the best and tenderest mutton and pork chops.
Fuel Value of Meats. Weight for weight, most of the butcher"s meats--beef, pork, mutton, and veal--have about the same food value, differing chiefly in the amount of fat that is mixed in with their fibres, and in certain flavoring substances, which give them, when roasted, or broiled, their special flavors. The different flavors are not of any practical importance, except in the case of mutton, which some people dislike and therefore can take only occasionally, and in small amounts.
The amount of fat in meats, however, is more important; and depends largely upon how well the animal has been fed. There is usually the least amount of fat in mutton, more in beef, and by far the greatest amount in pork. This fat adds to the fuel value of meat, but makes it a little slower of digestion; and its presence in large amounts in pork, together with the fact that it lies, not only in layers and streaks, but also mixed in between the fibres of the lean as well has caused this meat to be regarded as richer and more difficult of digestion than either beef or mutton. This, however is not quite fair to the pork, because smaller amounts of it will satisfy the appet.i.te and furnish the body with sufficient fuel and nutrition. If it be eaten in moderate amounts and thoroughly chewed, it is a wholesome and valuable food.
Veal is slightly less digestible than beef or mutton, on account of the amount of slippery _gelatin_ in and among its fibres; but if well cooked and well chewed, it is wholesome.
The other meats--chicken, duck, and other poultry, game, etc.--are of much less nutritive value than either beef, pork, or mutton, partly because of the large amount of waste in them, in the form of bones, skin, and tendons, and partly from the greater amount of water in them.
But their flavors make them an agreeable change from the staple meats.
Fish belongs in the same cla.s.s as poultry and consists of the same muscle substance, but, as you can readily see by the way that it shrinks when dried, contains far more water and has less fuel value. Some of the richer and more solid fishes, like salmon, halibut, and mackerel, contain, in addition to their protein, considerable amounts of fat and, when dried or cured, give a rather high fuel value at moderate cost. But the peculiar flavor of fish, its large percentage of water, and the special make-up of its protein, give it a very low food value, and render it, on the whole, undesirable as a permanent staple food. Races and cla.s.ses who live on it as their chief meat-food are not so vigorous or so healthy as those who eat also the flesh of animals. As a rule, it is not best to use fish as the main dish of a meal oftener than two or three times a week.
[Ill.u.s.tration: A BABY-MILK STATION
The milk sold here for a few cents is perfectly clean and pure, and is variously adapted to the needs of different babies. In many cities such milk stations have been established.]
Milk. Milk is an interesting food of great value because it combines in itself all three of the great cla.s.ses of food-stuffs,--protein, starch-sugar, and fat. Its protein is a substance called _casein_, which forms the bulk of curds, and which, when dried and salted, is called cheese. The fat is present in little tiny globules which give milk its whitish or milky color. When milk is allowed to stand, these globules of fat, being lighter, float up to the top and form a layer which is called cream. When this cream is skimmed off and put into a churn, and shaken or beaten violently so as to break the little film with which each of these droplets is coated, they run together and form a yellow ma.s.s which we call b.u.t.ter. In addition to the curd and fat, milk contains also sugar, called milk-sugar (_lactose_), which gives it its sweetish taste. And as a considerable part of the casein, or curd, is composed of another starch-like body, or animal starch, this makes milk quite rich in the starch-sugar group of food-stuffs.
All these substances, of course, in milk are dissolved in a large amount of water, so that when milk is evaporated, or dried, it shrinks down to barely one-sixth of its former bulk. It is, in fact, a liquid meat, starch-sugar, and fat in one; and that is why babies are able to live and thrive on it alone for the first six months of their lives. It is also a very valuable food for older children, though, naturally, it is not "strong" enough and needs to be combined with bread, puddings, meat, and fat.
Soups and Broths. Soups, broths, and beef teas are water in which meats, bones, and other sc.r.a.ps have been boiled. They are about ninety-eight per cent water, and contain nothing of the meat or bones except some of their flavor, and a little gelatin. They have little or no nutritive or fuel value, and are really Paper foods, useful solely as stimulants to appet.i.te and digestion, enabling us to swallow with relish large pieces of bread or crackers, or the potatoes, rice, pea-meal, cheese, or other real foods with which they are thickened. Their food value has been greatly exaggerated, and many an unfortunate invalid has literally starved on them. Ninety-five per cent of the food value of the meat and bones, out of which soups are made, remains at the bottom of the pot, after the soup has been poured off. The commercial extracts of meat are little better than frauds, for they contain practically nothing but flavoring matters.
Protein in Vegetables. Several vegetable substances contain considerable amounts of protein. One of these has already been mentioned,--the gluten or sticky part of bread,--and this is what has given wheat its well-deserved reputation as the best of all grains out of which to make flour for human food.
There is also another vegetable protein, called _legumin_, found in quite large amounts in dried beans and peas; but this is of limited food value, first because it is difficult of digestion, and secondly because with it, in dried peas and beans, are found a pungent oil and a bitter substance, which give them their peculiar strong flavor, both of which are quite irritating to the average person"s digestion. So distressing and disturbing are these flavoring substances to the civilized stomach, that, after thousands of attempts to use them more largely, it has been found that a full meal of beans once or twice a week is all that the comfort and health of the body will stand. This is really a great pity, for beans and peas are both nourishing and cheap. Nuts also contain much protein, but are both difficult of digestion and expensive.
Virtues and Drawbacks of Meats. Taken all together, the proteins, or meats, are the most nutritious and wholesome single cla.s.s of foods.
Their chief drawback is their expense, which, in proportion to their fuel value, is greater than that of the starches. Then, on account of their attractiveness, they may be eaten at times in too large amounts.
They are also somewhat more difficult to keep and preserve than are either the starches or the fats. The old idea that, when burned up in the body, they give rise to waste products, which are either more poisonous or more difficult to get rid of than those of vegetable foods, is now regarded as having no sufficient foundation. Neither is the common belief that meats cause _gout_ well founded.
The greatest danger connected with meats is that they may become tainted, or begin to spoil, or decay, before they are used.
Unfortunately, the ingenious cook has invented a great many ways of smothering, or disguising, the well-marked bad taste of decayed, or spoiled, meat by spices, onions, and savory herbs. So, as a general thing, the safest plan, especially when traveling or living away from home, is to avoid as far as possible hashes, stews, and other "made"
dishes containing meat. This is one of the ways in which spices and onions have got such a bad reputation for "heating the blood," or upsetting the stomach, when it is really the decayed meat which they are used to disguise that causes the trouble. Highly spiced dishes rob you of the services of your best guide to the wholesomeness of food--your nose.
Risks of Dirty Milk. The risks from tainting or spoiling are particularly great in the case of milk, partly on account of the dusty and otherwise uncleanly barns and sheds in which it is often handled and kept, and from which it is loaded with a heavy crop of bacteria at the very start; and partly because the same delicateness which makes it so easily digestible for babies, makes it equally easy for germs and bacteria to grow in it and spoil, or sour, it. You all know how disagreeable the taste of spoiled milk is; and it is as dangerous as it is disagreeable. A very large share of the illnesses of babies and young children, particularly the diseases of stomach and bowels which are so common in hot weather, are due to the use of spoiled, dirty milk.
[Ill.u.s.tration: CLEAN, DRY SUNNING YARDS AT A MODEL DAIRY]
There is one sure preventive for all these dangers, and that is _absolute cleanliness_ from cow to customer. All the changes that take place in milk are caused by germs of various sorts, usually floating in the air, that get into it. If the milk is so handled and protected, from cow to breakfast table, that these germs cannot get into it, it will remain sweet for several days.