It may appear almost paradoxical to commence our study of modern theories of diet with that which is the most ancient both in theory and practice, for the fleshless system of diet has never been without representatives at any period of the world's history. When one considers, however, that most of these theories have been enunciated as an apology for vegetarianism, or, in any case, that the tendency of most dietetic theorists is to gravitate towards a fleshless system, it will be evident that a careful consideration of this subject will prepare us for a more critical appreciation of the other theories.

There is reason to believe that the early history of all great nations was distinguished by a simplicity in diet and a preference for a frugivorous system. Greek and Roman athletes affected the fleshless diet. Caesar's armies conquered the Western world on maize and oil, and his writings bear testimony to the serious grumbling of the soldiers when mutton and beef were substituted. As nations increased in wealth, luxurious habits were developed and people abandoned themselves to voluptuous living. Laziness and excessive indulgence in animal food are usually associated under civilised conditions, and by degrees the nation deteriorated and, as a degenerate race, gave way under the constant pressure of the more heroic peoples, so that its decline and fall was assured.

History abounds with notable names of philosophers, poets, historians, etc, who found it an advantage for physical or moral reasons to abstain from flesh foods. Many of them endeavoured by voice and example to influence those around them, but with the exception of Buddha, whose authority was unique and, aided by climatic reasons, has persisted even until to-day, most of them lifted their voices in vain, and made little impression upon the nations to whom they spoke. The power of the pen was limited, and education was exclusive. Now that both are mighty forces amongst the people, the modern diet-reformer has a better chance; and under the potent influence of men like Kellogg, Graham, and Haig, the ranks of the vegetarians grow apace.

The Professional View

With a few notable exceptions, vegetarianism has never commended itself as a cult to the medical profession; but this is not a criterion of great value, for we know how conservative medical men have always been in the adoption of even such admitted facts as the advantages of total abstinence, the use of anaesthetics, the practice of vaccination, etc. It is interesting to note what present-day medical writers on dietetics have to say on the subject.

Davis says: "Few persons live upon a purely vegetarian diet. Those who do so, show languor and a disinclination for physical and mental work, lose vigour, and become less able to resist disease. Because a vegetable diet is an economical one, it has sometimes been forced upon bodies of labourers, but uniformly the decrease in the amount of work that they were able to perform more than counterbalanced the decreased expense of their food. In vegetables enough protein cannot be found to make it possible to substitute them for meat for the purpose of maintaining life and strength. As vegetable protein is very imperfectly digested and absorbed, a sufficient vegetable diet must be a very bulky one. It will maintain strength, and by eating vegetable food only, one may be able to lift as much, but he will not be able to work so fast as on a mixed diet, but will lack energy and alertness. It is quite evident from man's anatomical structure, physiological functions and habits of living, that a mixed diet is best adapted to his needs. At the same time it is unquestionably true that too much meat is ordinarily eaten by many individuals."

Hutchison, who is usually quoted with unction by vegetarians, says that a vegetable diet is too bulky, is less digestible in the stomach, and more inclined to undergo fermentation in the intestine, with the production of acids. Its proteins are less easily absorbed and it is greatly deficient in protein content. It tends to diminish energy and the power of resisting disease, and whilst advocating its adoption as a therapeutic agency he adds, "It is inadvisable in any case to continue the vegetarian plan for more than three weeks at a time."

Gautier recommends meat as necessary for the hard worker because "It still remains the chief stimulator and regenerator of muscle." He points out that the albuminoid principles of a vegetarian diet are only assimilable in the proportion of 83 per cent., whereas 96 per cent, reach the blood if they originate from meat. Its great lack, in his opinion, is the nerve-excitant function contained in the alkaloids of muscular flesh, with which neither gluten nor albumin can provide us. He believes that physical energy may be maintained without flesh, but looks upon man as omnivorous by instinct, dentition, digestive secretion, and his need of activity, and therefore that he must have stimulating aliments which furnish him with the most active and the most digestible plastic matter in the smallest bulk.

He considers the advantages of vegetarianism are (1) those which result from temperance, (2) that under its influence the tendency to arthritic, acute or rheumatic diatheses, neurasthenia, etc, disappears or is weakened, (3) that the character becomes more simple and the mind enjoys more rest and perhaps more acuteness.

Its disadvantages, on the other hand, are (1) that it is not suitable to a constitution weakened by hereditary illness, age, etc, or to delicate stomachs, (2) that it requires a greater volume of food, (3) that it furnishes too much lime and is apt to provoke arterio-sclerosis, (4) that an exclusively herbaceous vegetable diet provokes intestinal catarrh and visceroptosis. He thinks that many of these disadvantages may be eliminated by degrees, as hereditary custom must be allowed for, and that whilst an absolute vegetable diet is, as a rule, unsuitable for white men, this statement does not apply to the lacto-vege-tarian system. In his opinion this has the following advantages. It alkalises the blood, accelerates oxidations, diminishes nitrogenous losses and toxins, diminishes the tendency to skin disease, arthritism, and congestion of the internal organs, makes men peaceful, not aggressive nor violent. It is practical and rational, and should be accepted and commended by those who pursue the high ideal of the formation and education of gentle, intelligent, artistic, and nevertheless prolific, righteous, and active races.

These three are excellent samples of the opinions of recognised writers on dietetics, and most of the others advance views which are in complete accord with them. Voit asserts that it is perfectly possible to subsist on a vegetable diet, but that a mixed diet is preferable. Rutgers demonstrated that animal protein could be entirely replaced by vegetable protein without any appreciable change in the nitrogen balance. Craemer declares that sufficient nourishment for the body will be found in a diet of vegetables, eggs and milk, but if the eggs and milk be omitted, the body will find it much more difficult and less economical to obtain its requisite quantity of protein.