There can be no doubt that, whatever other function food may or may not have, it replaces broken-down tissue. The tissue-wastes of the preceding day are replenished by the food eaten; so the body remains about the same in weight, no matter how much exercise be taken, or how much tissue is broken down. These tissues are very complex in their nature, and a variety of food is consequently necessary to restore the tissues destroyed—food containing a number of elements (the counterpart of the elements destroyed), being necessary to offset the waste. Proteid, fats, carbohydrates, and various salts are, therefore, necessary in the food; and no food that does not contain these constituents, in larger or smaller quantities, can be used by the body, or can be classed as a true “food.” Other things being equal, therefore, it may be said that a food is nutritious and capable of sustaining life in proportion to its complexity—the best food being one that most nearly supplies the wastes of the tissues. If an article of diet contains only one of the essential elements necessary for supporting life, the body, if fed upon it, will waste away and die—no matter how much of that food be eaten. In certain experiments conducted upon dogs, it was found that, when they were fed upon fat—e.g. they became round, plump, embonpoint, and yet died of inanition! The same would be true of any other single article of diet. If an animal were fed upon it, he would surely die, sooner or later. Proteids are supposed to supply most of the muscle-forming elements, and a part of the energy expended by the body; fats and carbohydrates are supposed to be of use chiefly in supplying heat and energy to the system. The mineral salts that are contained in the foods do not fulfil any definite function, so far as is known; but they are very essential, nevertheless. If a diet lacks these salts entirely, the body wastes away and dies of “saline starvation.” It will thus be apparent that foods very rapidly and very forcibly affect the state of the health, and even the life of the individual. Food, it must be remembered, makes blood; and the blood is absolutely dependent upon the food supply for its character and composition. If the food be poisonous in character, the blood soon becomes tainted, and the mind, no less than the body, shows the effects of this poisoning process. On any theory we may hold of the nature of mind, and its connection with the body, it is certainly dependent upon the body for its manifestation, in this life; and is coloured and influenced by the state of the body, and by the condition of the blood. This I have shown more fully in another place. We shall also see the effects of diet upon the mind, more clearly, as we proceed in the present volume.

From what has been said, it will at all events be apparent that this question of the food supply is a very important one—indeed one of the most important before the world to-day. The first thought, the first instinct, of any animal, is to search for and secure food; self-preservation is the most powerful instinct in the world, and the nutrition of the body occupies first place, as one means of preserving life. In the lower organisms, we see this very clearly; they spend almost the whole of their lives in searching for and devouring food; but as we ascend the scale of evolution, we find less and less space devoted, in the body, to the digestive organs, and more and more to the brain, and instruments of the mind. It would appear, therefore, that the higher we ascend in the scale of evolution, the less proportionate space in the body is devoted to the purely animal processes, and the more to the mental and spiritual sides of man. As the mentality increases, the need for food decreases: this is a very significant law—for such I believe it to be. It would seem to indicate that man attained the highest level, so far as his physical or physiological structure was concerned; and that evolution thenceforward tended to develop that side of man which rendered possible the increased mental and spiritual characteristics. However, I shall not dwell too strongly upon that point now.

Although an adequate supply of food is very necessary to all organisms, there is but little danger that anyone in a civilised community would run the risk of starving to death, because of the lack of food. The tendency is all the other way, and most persons eat, not too little, but far too much, food. Even the very poor, and especially the babies of the very poor—eat too often, and too much. This may seem strange, but it becomes more rational and intelligible when we take into account the fact that the human body needs so little food, in reality, to supply the wastes of the day, that the very poor, even if they have far less food than the majority, still have too much. The average person eats at least three times more food than his system really requires; and it is due to this very fact, I earnestly believe, that much of the suffering and of the insanity, and many of the diseases, are so constantly with us. In his recently published works, Professor Chittenden has shown with great detail that the average standard “dietary tables” of the physiologists have been far too high; and that the average man can cut down his proteid intake fully one third, without detriment, but, on the contrary, with added benefit to himself. The majority of persons eat far more than the physiologists have said to be necessary; and now it has been shown that the physiologists have set the standard three times too high! It would appear, therefore, that most persons eat more than three times too much proteid; and the same has been found to hold good of the fats and carbohydrates, in a lesser degree, also. But while the fats and carbohydrates can be eliminated by the system, or stored up within it, without positive danger, proteid in excess creates an abundance of uric acid, and causes much harm to the system throughout. It is the excess of proteid that is the chief cause of many of the diseases from which mankind suffers; and, if health is to be maintained, we must see to it that this great excess is not ingested into the body. While keeping up the due allowance, we must be careful not to eat those foods which tend to introduce this excess into the system; and, by avoiding them, it will be seen that we thereby avoid all danger of creating an undue amount of uric acid, and consequently of suffering from the induced diseases.

Now, it is a well-known fact that meat contains a large proportion of protein; and further, that it has a great tendency to create uric acid in the system, owing to the decaying cell-nuclei that form a large part of its structure. Meat is by no means a clean article of diet, but on the contrary a very unclean one; and many foods, supplying an equal amount of proteid matter, are to be preferred, for the reason that they supply less toxic material—which invariably accompanies flesh-meat. It must be remembered that the tissues of all animals contain a certain amount of poisonous material—simply by reason of the fact that the animal has lived at all—since all animals are constantly creating poisons within their bodies, by the very process of living. These poisons are being thrown off by the body every minute throughout the day; and it is because of that fact the animal is enabled to remain alive at all. Were this process of elimination checked for a few hours, death by poisoning would inevitably result—in consequence of the poisons formed by the body itself. All animals, then, create these poisons; and it would be impossible to find an animal body without them. So that, when we eat the flesh of any animal, we must eat, together with the nutritious portions, these poisons—which are practically inseparable from all animal tissue. That is, whenever we eat meat, we invariably eat, at the same time, a certain quantity of poison—which it is impossible to avoid! I shall elaborate this idea at considerable length in my chapter on the hygiene of diet. In this place I shall only call attention to that fact—the strongest argument of all, to my mind, for abstaining from flesh; and shall point out that, if any diet furnishes all the nutritious properties of meat, without these poisons, it is certainly to be preferred, on that account. We shall see, when we come to the chapter devoted to the chemistry of foods, that all the elements contained in meat are also contained in a purer and better form in other substances—grains, some vegetables, and in nuts—and in as large or larger proportions than they are in meat.

It will thus be seen that certain foods are better for us than others—a fact which daily observation confirms. Everyone knows that certain articles of diet are indigestible, others not so much so: that some are nutritious, and others hardly of any food value at all. Some foods are better for us than others, therefore; and, if we wish to maintain our health, it is obvious that we should eat those foods, and only those foods, as a general thing, which can be shown to be of use and benefit to the body. If some foods are thus more wholesome than others, does it not behove everyone interested in the health and care of his body—and especially all those interested in hygiene, or the improvement of the race—to endeavour to ascertain what these foods are, those most natural and best for the human body; and, having found them, to advise all who wish to maintain their bodies in the highest state of health, to live upon these foods—or at least to make them the staple articles of their diet? Believing this to be most certainly true, I shall devote myself, in the present volume, to a careful search through the records and evidences of science, and endeavour to ascertain in what man’s natural food consists; and, having found the food which is indicated by nature as the best and most natural for man, I shall proceed to give my reasons for thinking that this food is the most wholesome, and why it is that all other foods must be more or less harmful to the system. This done, we shall be in a position to define what foods are “natural” for man, and indicate why it is that they are the most wholesome.

In order to clarify the problem, then, and clear away any misconceptions that may arise in the reader’s mind, I shall state here what my conclusions are, and my reasons for thinking them sound. Assuming that there is an “ideal” diet of some sort—that upon which the human race originally lived, and which it should still live upon, if it wishes to maintain the best possible health—I have gone carefully through the various food-stuffs, and, by careful analysis, have shown that all meats are injurious to the body, for the reason that they are not suited to it, by reason of its anatomical structure—and, further, by the facts of experience and hygiene, which clearly indicate that if man eats meat, he suffers in consequence. These arguments will be found in full in the book. I also found that there were many objections to all vegetables, to cereals, grains and flour of all kinds; to soups, to bread and eggs, to butter, milk, cheese, and to all dairy products. Most cookbooks and works devoted to the hygiene of foods have been in the habit of pointing out all the beneficial and good qualities of these foods, and saying very little about their bad qualities. In this book, I have pointed out all the bad qualities, and have insisted that these so far offset their good qualities as to show them utterly unfitted for human food, and consequently to be discarded from any truly hygienic diet. Thus, by a process of elimination, we are forced to the conclusion that the only foods that are really natural to man, those best suited to his organism, are fruits and nuts—the diet of his anthropoid brethren, and man’s own natural diet, as is clearly indicated by his anatomical structure. Fruits and nuts will alone suffice to maintain the human body in the highest state of health; and are the foods which should be adopted, and eaten, by mankind, to the exclusion of all others. From them, he can obtain all the elements necessary for the upbuilding of a healthy body; and from them he can derive the greatest amount of health and strength, and the greatest amount of energy.

Many persons would be willing to concede, I fancy, that man can live without meat—indeed, there is no escaping this conclusion, since thousands of persons are actually doing so. But not very many would be willing to concede, probably, that all breads, grains, and vegetables are to be abandoned as unfit for human food also! They would be unwilling to admit that! And yet I think it can be shown very conclusively that none of these foods are intended for the human being, any more than is the grass of the field. Each genus has its own particular food, allotted by nature; and man’s food consists—or should consist—of fruit and nuts. Further, these fruits and nuts should be eaten uncooked—in their original, primitive form. I am convinced that cooking ruins nearly all foods treated in that manner—my arguments for this will be found in full in the chapter on “The Fruitarian Diet.”

If this be true, as I most firmly believe it is—it will be seen that practically all other foods are naturally barred out, by the very nature of the case. Certainly no one would care to eat his meat raw; and all vegetables, with very few exceptions, would also fall under the ban, for but few of them can well be eaten without cooking. Grains, also, are very unappetising, when eaten raw, and it is now well known that but a small amount of their starch is converted properly, in the body, unless the grains are well cooked; so that all these foods would be eliminated from the diet, and practically nothing left but fruits and nuts! Although this may seem appalling to the average reader, it is the logical outcome of the theory, and I am convinced the right interpretation of the facts. The fruitarian diet is the one best suited for man; and the one upon which he can live best and longest. I myself have lived upon this fruit and nut diet almost exclusively for several years, and I may perhaps say that I am always in excellent spirits and condition, and a source of constant surprise to my friends in that I seem to possess an untiring energy and ability for work. I say this, not to boast, but to show that a diet of this character is perfectly compatible with health and strength; and I believe that almost any person could double his energies, his health, and his self-respect by adopting a diet of this character. For it has a tremendous effect upon the mental and moral, no less than upon the physical life, as I shall presently endeavour to show.

With the invention of fire, however, many articles of food became edible which had not been edible before. Finding that grains and roots, and certain weeds (vegetables) could be eaten, when cooked, although they were uneatable when raw, man took to cooking his food, and substituting this food for a portion of his original diet—which was probably scarce at the time. In this way, the cooking of food probably originated. It began in the far-off ages, and has been handed down to us—a legacy of barbarism, to which man rigidly clings, in the vain effort to preserve a distinction between himself and other animals—who do not cook their food—because of this fact! He prides himself that he is the only “cooking animal”! If man would only learn that it is owing to this very process of cooking that much of the suffering, and many of the ills from which mankind suffers, are due!

Many persons imagine that, if they returned to a primitive diet of this character, they would become as the savages—wild and uncivilised. They “don’t want to become like the animals,” they will say. They wish to remain “civilised,” and not return to a state of savagery and barbarism! There is no logic in this argument—indeed, no sense. Because a man lives upon fruits and nuts, it is, of course, no reason why he should return to a primitive state, mentally; indeed, there is far less evidence for this than there is that man becomes like the carnivorous animals by eating meat. There is evidence for that! But living upon fruits and nuts has no other effect than to elevate the tone and character of the body; to increase its energies and to render the mind clearer and more active. If these objectors to the fruitarian diet would only study physiology and human nature before passing any such absurd judgment upon the facts, their arguments would have more force—but then, in that case, they would not raise the arguments at all! Of course, this whole idea is conclusively proved to be erroneous by the facts in the case.

There is one other point I should like to touch upon, though briefly, before passing on to the main argument of the book. The usual position with regard to food, and its functions in the body is this. Food has three functions: (1) The replacement of tissues which have been broken down as the result of the day’s work; (2) the maintenance of the bodily energy; and (3) the maintenance of the bodily heat. Now, in my former book,[1] I advanced a number of facts tending to show that food has but one function—replacing broken-down tissue. It supplies no heat and no energy whatever to the body, at any time, or under any circumstances. Both the heat and the energy are due to another source altogether, and not to the food ingested.[2] I cannot enumerate the arguments in support of this position here; they will be found in full in the work referred to; but I would point out that, if this theory were true, it would cause us to modify very largely the views entertained as to the necessary amount of food required by the body. Now, a large percentage of the food eaten is supposed to create heat and energy, or at least liberate it, and is eaten for that express purpose. But if it be true that food has no other function than to supply the body with material for the rebuilding of its structures and tissues, it will be apparent that far less food is necessary than is usually thought to be necessary by the physiologists; and this would account for the enormous differences in quantity said to be

necessary by the various physiologists. The truth of the matter doubtless is, that the smallest amount of food is that which is necessary, and all amounts over and above this are passed through the body at an expense of the vital energies, and to the detriment of the vital economy. However, I shall not dwell unduly upon this point, in this place; partly because Dr Rabagliati and myself are, as yet, practically alone in our belief that the energy of the body does not come from the food; and partly because this book is devoted to the quality of the various foods, rather than to their quantity—as was my former book. Both—quantity and quality—are of great interest and importance; but as I have already said all that is necessary regarding one aspect of this question—that of quantity—I feel that a somewhat detailed discussion of the “quality” of food could not fail to be of interest. I accordingly turn to this aspect of the problem; and shall devote the remaining pages of this book to a discussion of the relative qualities and proportions of the various foods.