I think there is no more important single question about health than the question of how much food we should eat. It is one about which there is a great deal of controversy, even among the best authorities. We shall try here for a common-sense solution. At the outset we have to remind ourselves of the distinction we tried to draw between nature and man. To what extent can civilized man rely upon his instincts to keep him in perfect health?

Let us begin by considering the animals. How is their diet problem solved? Horses and cattle in a wild state are adjusted to certain foods which they find in nature, and so long as they can find it, they have no diet problem. Man comes, and takes these animals and domesticates them; he observes their habits, and gives to them a diet closely approaching the natural one, and they get along fairly well. But suppose the man, with his superior skill in agriculture, taking wild grain and planting it, reaping and threshing it by machinery, puts before his horse an unlimited quantity of a concentrated food such as oats, which the horse can never get in a natural state—will that horse's instincts guide it? Not at all. Any horse will kill itself by overeating on grain.

I have read somewhere a clever saying, that a farm is a good place for an author to live, provided he can be persuaded not to farm it. But once upon a time I had not heard that wise remark, and I owned and tried to run a farm. I had two beautiful cows of which I was very proud, and one morning I woke up and discovered that the cows had got into the pear orchard and had been feeding on pears all night. In a few hours they both lay with bloated stomachs, dying. A farmer told me afterwards that I might have saved their lives, if I had stuck a knife into their stomachs to let out the gas. I do not know whether this is true or not. But my two dead cows afford a perfect illustration of the reason why civilized man cannot rely upon his instincts and his appetites to tell him when he has had enough to eat. He can only do this, provided he rigidly restricts himself to the foods which he ate in the days when his teeth and stomach and bowels were being shaped by the process of natural selection. If he is going to eat any other than such strictly natural foods, he will need to apply his reason to his diet schedule.

In a state of nature man has to hunt his food, and the amount that he finds is generally limited, and requires a lot of exercise to get. Explorers in Africa give us a picture of man's life in the savage state, guided by his instincts and very little interfered with by reason. The savages will starve for long periods, then they will succeed in killing a hippopotamus or a buffalo, and they will gorge themselves, and nearly all of them will be ill, and several of them will die. So you see, even in a state of nature, and with natural foods, restraint is needed, and reason and moral sense have a part to play.

What do reason and moral sense have to tell us about diet? Our bodily processes go on continuously, and we need at regular intervals a certain quantity of a number of different foods. The most elementary experiment will convince us that we can get along, maintain our body weight and our working efficiency upon a much smaller quantity of food than we naturally crave. Civilized custom puts before us a great variety of delicate and appetizing foods, upon which we are disposed to overeat; and we are slow observers indeed if we do not note the connection between this overeating and ill health. So we are forced to the conclusion that if we wish to stay well, we need to establish a censorship over our habits; we need a different diet regimen from the haphazard one which has been established for us by a combination of our instincts with the perversions of civilization.

Up to a few years ago, it was commonly taken for granted by authorities on diet that what the average man actually eats must be the normal thing for him to eat. Governments which were employing men in armies, and at road building, and had to feed them and keep them in health, made large scale observations as to what the men ate, and thus were established the old fashioned "diet standards." They are expressed in calories, which is a heat unit representing the quantity of fuel required to heat a certain small quantity of water a certain number of degrees. In order that you may know what I am talking about, I will give a rough idea of the quantity of the more common foods which it takes to make 100 calories: one medium sized slice of bread, a piece of lean cooked steak the size of two fingers, one large apple, three medium tablespoonfuls of cooked rice or potatoes, one large banana, a tablespoonful of raisins, five dates, one large fig, a teaspoonful of sugar, a ball of butter the size of your thumbnail, a very large head of lettuce, three medium sized tomatoes, two-thirds of a glass of milk, a tablespoonful of oil. You observe, if you compare these various items, how little guidance concerning food is given by its bulk. You may eat a whole head of lettuce, weighing nearly a pound, and get no more food value than from a half ounce of olive oil which you pour over it. You may eat enough lean beefsteak to cover your plate, and you will not have eaten so much as a generous helping of butter. A big bowl of strawberries will not count half so much as the cream and sugar you put over them. So you may realize that when you eat olive oil, butter, cream, and sugar, you are in the same danger as the horse eating oats, or as my two cows in the pear orchard; and if some day a surgeon has to come and stick a knife into you, it may be for the same reason.

The old-fashioned diet standards are as follows: Swedish laborers at hard work, over 4,700 calories; Russian workmen at moderate work, German soldiers in active service, Italian laborers at moderate work, between 3,500 and 3,700 calories; English weavers, nearly 3,500 calories; Austrian farm laborers, over 5,000 calories. Some twenty years ago the United States government made observations of over 15,000 persons, and established the following, known as the "Atwater standards": men at very hard muscular work, 5,500 calories; men at moderately active muscular work, 3,400 calories; men at light to moderate muscular work, 3,050 calories; men at sedentary, or women at moderately active work, 2,700 calories.

In the last ten or fifteen years there has arisen a new school of dietetic experts, headed by Professors Chittenden and Fisher of Yale University. Professor Chittenden has published an elaborate book, "The Nutrition of Man," in which he tells of long-continued experiment upon a squad of soldiers and a group of athletes at Yale University, also upon average students and professors. He has proved conclusively that all these various groups have been able to maintain full body weight and full working efficiency upon less than half the quantity of protein food hitherto specified, and upon anywhere from one-half to two-thirds the calory value set forth in the former standards.

When I first read this book, I set to work to try its theories upon myself. During the five or six months that I lived on raw food, I took the trouble to weigh everything that I ate, and to keep a record. It is, of course, very easy to weigh raw foods exactly, and I found that I lived an active life and kept physical health upon slightly less than 2,500 calories a day. I have set this as my standard, and have accustomed myself to follow it instinctively, and without wasting any thought upon it. Sometimes I fall from grace; for I still crave the delightful cakes and candies and ice cream upon which I was brought up. I always pay the penalty, and know that I will not get back to my former state of health until I skip a meal or two, and give my system a chance to clean house. The average man will find the regimen set forth in this book austere and awe-inspiring; I do not wish to pose as a paragon of virtue, so perhaps I should quote a sarcastic girl cousin, who remarked when I was a boy that the way to my heart was with a bag of ginger-snaps. I live in the presence of candy stores and never think of their existence, but if someone brings candy into the house and puts it in front of me, I have to waste a lot of moral energy in letting it alone. A few years ago I had a young man as secretary who discovered this failing of mine, and used to afford himself immense glee by buying a box of chocolates and leaving it on top of my desk. I would give him back the box—with some of the chocolates missing—but he would persist in "forgetting it" on my desk; he would hide and laugh hilariously behind the door, until my wife discovered his nefarious doings, and warned me of them.

Professor Chittenden states quite simply the common sense procedure in the matter of food quantity. Find out by practical experiment what is the very least food upon which you can do your work without losing weight. That is the correct quantity for you, and if you are eating more, you certainly cannot be doing your body any good, and all the evidence indicates that you are doing it harm. You need not have the least fear in making this experiment that you will starve yourself. Later on, in a chapter on fasting, I shall prove to you that you carry around with you in your body sufficient reserve of food to keep you alive for eighty or ninety days; and if you draw on a small quantity of this you do not do yourself the slightest harm. Cut down the amount of your food; eat the bulky foods, which contain less calory value, and weigh yourself every day, and you will be surprised to discover how much less you need to eat than you have been accustomed to.

One of the things you will find out is that your stomach is easily fooled; it is largely guided by bulk. If you eat a meal consisting of a moderate quantity of lean meat, a very little bread, a heaping dish of turnip greens, and a big slice of watermelon, you will feel fully satisfied, yet you will not have taken in one-third the calory value that you would at an ordinary meal with gravies and dressings and dessert. The bulky kind of food is that for which your system was adapted in the days when it was shaped by nature. You have a large stomach, many times as large as you would have had if you had lived on refined and concentrated foods such as butter, sugar, olive oil, cheese and eggs. You have a long intestinal tract, adapted to slowly digesting foods, and to the work of extracting nutrition from a mass of roughage. You have a very large lower bowel, which Metchnikoff, the Russian scientist, one of the greatest minds who ever examined the problems of health, declares a survival, the relic of a previous stage of evolution, and a source of much disease. The best thing you can do with that lower bowel is to give it lots of hay, as it requires; in other words, to eat the salads and greens which contain cellulose material. This contains no food value, and does not ferment, but fills the lower bowel and stimulates it to activity.

If you eat too much food, three things may happen. First, it may not be digested, and in that case it will fill your system with poisons. Second, it may be assimilated, but not burned up by the body. In that case it has to be thrown out by the kidneys or the sweat glands, and this puts upon these organs an extra strain, to which in the long run they may be unequal. Or third, the surplus material may be stored up as fat. This is an old-time trick which nature invented to tide you over the times when food was scarce. If you were a bear, you would naturally want to eat all you could, and be as fat as possible in November, so that you might be able to hunt your prey when you came out from your winter's sleep in April. But you are not a bear, and you expect to eat your regular meals all winter; you have established a system of civilization which makes you certain of your food, and the place where you keep your surplus is in the bank, or sewed up in the mattress, or hidden in your stocking. In other words, a civilized man saves money, and the habit of storing globules of grease in the cells of his body is a survival of an old instinct, and a needless strain upon his health. Not merely does the fat man have to carry all the extra weight around with him, but his body has to keep it and tend it; and what are the effects of this is fully shown by life insurance tables. People who are five or ten per cent over weight have five or ten per cent more chance of dying all the time, while people who are five or ten per cent under weight have five or ten per cent more than the average of life expectation. There is no answer to these figures, which are the result of the tabulation of many hundreds of thousands of cases. The meaning of them to the fat person is to put himself on a diet of lean meat, green vegetables and fresh fruits, until he has brought himself down, not merely to the normal fatness of the civilized man, but to the normal leanness of the athlete, the soldier on campaign, and the student who has more important things to think about than stuffing his stomach.

There is, of course, a certain kind of leanness which is the result of ill health. There are wasting diseases; tuberculosis, for example, and anemia. There are people who worry themselves thin, and there are a few rare "spiritual" people, so-called, who fade away from lack of sufficient interest in their bodies. That is not the kind of leanness that I mean, but the active, wiry leanness, which sometimes lives a hundred years. Nearly always you will find that such people are spare eaters; and you will find that our ideal of rosy plumpness, both for adults and children, is a wholly false notion. We once had in our home as servant an Irish girl, who was what is popularly called "a picture of health," with those beautiful flaming cheeks that Irish and English women so often have. She was in her early twenties, and nobody who knew her had any idea but that her health was perfect. But one morning she was discovered in bed with one side paralyzed, and in a couple of weeks she was dead with erysipelas. The color in her cheeks had been nothing but diseased blood vessels, overloaded with food material; and with the blood in that condition, one of the tiny vessels in the brain had become clogged.

In the same way I have seen children, two or three years old, plump and rosy, and considered to be everything that children should be; but pneumonia would hit them, and in two or three days they would be at death's door. I do not mean that children should be kept hungry; on the contrary, they should have four or five meals a day, so that they do not have a chance to become too hungry. But at those meals they should eat in great part the bulky foods, which contain the natural salts needed for building the body. If a child asks for food, you may give it an apple, or you may give it a slice of bread and butter with sugar on it. The child will be equally well content in either case; but it is for you, with your knowledge of food values, to realize that the bread with butter and sugar contains two or three times as much nutriment as the apple, but contains practically none of the precious organic salts which will make the child's bones and teeth.

So far I have discussed this subject as if all foods grew on bushes outside your kitchen door, and all you had to do was to go and pick off what you wanted. But as a matter of fact, foods cost money, and under our present system of wage slavery, the amount of money the average person can spend for food is strictly limited. In a later book I am going to discuss the problem of poverty, its causes and remedies. All that I can do here is to tell you what foods you ought to have, and if society does not pay you enough for your work to enable you to buy such foods, you may know that society, is starving you, and you may get busy to demand your rights as human beings. Meantime, however, such money as you do have, you want to spend wisely, and the vast majority of you spend it very unwisely indeed.

In the first place, a great many of the simplest and most wholesome foods are cheap—often because people do not know enough to value them. We insist upon having the choice cuts of meats, because they are more tender to the teeth, but the cheaper cuts are exactly as nutritious. We insist upon having our meats loaded with fat, although fatness is an abnormal condition in an animal, and excess of fat is a grave error in diet. I live in a country where jack rabbits are a pest, and in the market they sell for perhaps one-fourth the cost of beef, and yet I can hardly ever get them, because people value them so little as food; they prefer the meat of a hog which has been wallowing in a filthy pen, and has been deliberately made so fat that it could hardly walk!

I have already spoken of prunes, a much despised and invaluable food. All the dried fruits are rich in food values, and if we could get them untreated by chemicals, they would be worth their cost. I was brought up to despise the cheaper vegetables, such as cabbage and turnips; I never tasted boiled cabbage until I was forty, and then to my great surprise I made the discovery that it is good. Raw cabbage is as valuable as any other salad; it is a trifle harder to digest for some people, but I do not believe in pampering the stomach. Both potatoes and rice are cheap and wholesome, if only we would get unpolished rice, and if we would leave the skins on the potatoes until after they are cooked. Nearly all the mineral salts of the potato are just under the outer skin, and are removed by the foolish habit of peeling them.

The prices of food differ so widely at different seasons and in different parts of the world, that there is not much profit in trying to figure how cheaply a person can live. I have found that I spend for the diet I have indicated here, from sixty to eighty cents a day. I do not buy any fancy foods, but on the other hand, I do not especially try to economize; I buy what I want of the simple everyday foods in their season. Most everyone will find that it is a good business proposition to buy the foods which he needs to keep in health. If the average workingman would add up the money he spends, not merely in the restaurants, but in the candy stores, the drug stores, the tobacco stores, and the offices of doctors and dentists, he would find, I think, that he could afford to buy himself the necessary quantity of wholesome natural foods. For a family of three, in the place where I live, enough of these foods can be purchased for a dollar a day, and this is about one-fourth what common labor is being paid, and one-eighth of what skilled labor is being paid. I will specify the foods: a pound and a half of shoulder steak, a loaf of whole wheat bread or a box of shredded wheat biscuit, a head of cabbage, a pound of prunes, and four or five pounds of apples.

There are many ways of saving in the purchase of food if you put your mind upon it. If you are buying prunes, you may pay as high as fifty cents or a dollar a pound for the big ones, and they are not a bit better than the tiny ones, which you can buy for as low as eight cents a pound in bulk. When bread is stale, the bakers sell it for half price, despite the fact that only then has it become fit to eat. If you buy canned peaches, you will pay a fancy price for them, and they will be heavy with cane sugar; but if you inquire, you find what are known as "pie peaches," put up in gallon tins without sugar, and at about half the price. The butcher will sell you what he calls "hamburg steak" at a very low price, and if you let him prepare it out of your sight, he will fill it with fat and gristle; but let him make some while you watch, and then you have a very good food. One of my diet rules is that I do not trust the capitalist system to fix me up any kind of mixed or ground or prepared foods. I have not eaten sausage since I saw it made in Chicago.

Also there is something to know about the cooking of foods, since it is possible to take perfectly good foods and spoil them by bad cooking. Once upon a time our family discovered a fireless cooker, and thought that was a wonderful invention for an absent-minded author and a wife who is given to revising manuscripts. But recent investigations which have been made into the nature of the "vitamines," food ferments which are only partly understood, suggest that prolonged cooking of food may be a great mistake. The starch has to be cooked in order to break the cell walls by the expansion of the material inside. Twenty minutes will be enough in the case of everything except beans, which need to be cooked four or five hours. Meat should be eaten rare, except in the case of pork, which harbors a parasite dangerous to the human body; therefore pork should always be thoroughly cooked. The white of eggs is made less digestible by boiling hard or frying. Eggs should never be allowed to boil; put them on in cold water, and take them off as soon as the water begins to boil. It is not necessary to cook either fresh fruit or dried. The dried fruits may be soaked and eaten raw, but I find that several fruits, especially apples and pears, do not agree with me well if they are eaten raw, so I stew them for fifteen or twenty minutes. I have no objection to canned fruits and vegetables, provided one takes the trouble in opening them to make sure there is no sign of spoiling. If you put up your own fruits, do not put in any sugar. All you have to do is to let them boil for a few minutes, and to seal them tightly while they are boiling hot. The whole secret of preserving is to exclude the air with its bacteria.

If you live on a farm, you will have no trouble in following the diet here outlined, for you can produce for yourselves all the foods that I have recommended; only do not make the mistake of shipping out your best foods, and taking back the products of a factory, just because you have read lying advertisements about them. Take your own wheat and oats and corn to the mill, and have it ground whole, and make your own breads and cereals. Try the experiment of mixing whole corn meal with water and a little salt, and baking it into hard, crisp "corn dodgers." I do not eat these—but only because I cannot buy them, and have no time to make them.

Another common article of food which I do not recommend is salted and smoked meats. I do not pretend to know the effects of large quantities of salt and saltpetre and wood smoke upon the human system, but I know that Dr. Wiley's "poison squad" proved definitely that a number of these inorganic minerals are injurious to health, and I prefer to take fresh meat when I can get it. I use a moderate quantity of common salt on meat and potatoes, because there seems to be a natural craving for this. I know that many health enthusiasts insist that I am thus putting a strain on my kidneys, but I will wait until these health enthusiasts make clear to me why deer and cattle and horses in a wild state will travel many miles to a salt-lick. I have learned that it is easy to make plausible statements about health, but not so easy to prove them. For example, I was told that it is injurious to drink water at meals, and for years I religiously avoided the habit; but it occurred to some college professor to find out if this was really true, and he carried on a series of experiments which proved that the stomach works better when its contents are diluted. The only point about drinking at meals is that you should not use the liquid to wash down your food without chewing it.

I can suggest two other ways by which you may save money on food. One is by not eating too much, and another is by eating all that you buy. The amount of food that is wasted by the people of America would feed the people of any European nation. The amount of food that is thrown out from any one of our big American leisure class hotels would feed the children of a European town. I think it may fairly be described as a crime to throw into the garbage pail food which might nourish human life. In our family we have no garbage pail. What little waste there is, we burn in the stove, and my wife turns it into roses. It consists of the fat which we cannot help getting at the butcher's, and the bones of meat, and the skins of some fruits and vegetables. It would never enter into our minds to throw out a particle of bread, or meat, or other wholesome food. If we have something that we fear may spoil, we do not throw it out, but put it into a saucepan and cook it for a few minutes. If you will make the same rule in your home, you will stop at least that much of the waste of American life; and as to the big leisure class hotels, and the banquet tables of the rich—just wait a few years, and I think the social revolution will attend to them!