THE celebrated English physician, Harvey, who lived in the seventeenth century, treated one of his patients, suffering from obesity, by a diet consisting almost exclusively of meat, that is to say, albumin. As a result of this, the patient became much thinner. It should be mentioned, however, that such a diet, which since then has often been resorted to in obesity, causes a series of unpleasant symptoms in addition to the decided loss of flesh, to wit, fatigue, faintness, perspiration, nervous excitability, etc.
Such a one-sided meat diet always brings about a result which in every rational diet is to be carefully avoided, namely, a diminution of the amount of albumin in the body. Such a pronounced loss of bodily albumin may often have very serious consequences. These generally occur, as experiments have shown, when man or animals are restricted to an albumin-containing food to the exclusion of both carbohydrates and fats. Even when large quantities of albumin are administered there will be a very considerable loss of albumin, and when dogs are fed upon such a diet it is not possible to keep up their nitrogen balance. This occurs also when fats have been excluded from the nourishment. It is only by administering carbohydrates that this is possible. When these are absent there will be a considerable loss of flesh. In diabetic patients, after such a faulty, exclusively meat and fat diet, there will be a decided aggravation of the condition, together with the formation of acetone bodies, and very frequently such patients die in coma, owing to acid poisoning. When, however, carbohydrates are added to the diet, a great improvement will often be noticed.
An almost exclusive carbohydrate diet, that is to say, a starchy diet, may also give rise to bad results. When starch is taken in too large quantities, acid fermentation takes place in the intestinal canal and intestinal peristalsis is greatly in-creased. In consequence the food is very soon excreted from the intestine without having been absorbed in the fluids of the body, and emaciation will result. Persons who nourish them-selves almost exclusively upon carbohydrates, as rice, for in-stance, like the poor Hindoos, are, as a rule, very thin. With Europeans, too, who advocate a purely vegetable diet, the same thing will be observed. Since in this way too little albumin is taken, and very often fat as well, this should also be considered a one-sided diet.
By a one-sided diet I mean one which is almost entirely or at least principally composed of one of the three main groups of foods, albumins, carbohydrates, or fats, and in which the other two are absent, or one absent and the other but slightly represented. In this sense the purely vegetable diet is certainly one-sided, for, although it may sometimes, though not very often, contain a fair percentage of carbohydrates, there is almost always much too little albumin. When the albumin is not sufficiently represented, more fat should be taken ; this, however, is rarely done by vegetarians.
When anyone lives solely upon plant food, the assimilation of the food substances by means of the intestine is but poorly accomplished. Atwater, basing himself upon his numerous experiments, found that with a purely vegetable diet up to 28.26 per cent. of the nitrogenous substance of the food was eliminated unused. When a moderate amount of animal food was added assimilation was considerably improved, only 11.59 per cent. being lost. With a plentiful supply of animal food, only 8.88 per cent was lost. According to the experiments of Atwater, it is impossible to retain the nitrogen balance with vegetable foods only.
Although milk contains all three of the main nutrient groups in the proper proportions, we must, nevertheless, consider a diet consisting of milk alone as one-sided, since only one kind of food is taken. An adult person can get on very well with milk only during a certain time, say four to six weeks; but when persisted in, this mode of nourishment is quite as injurious as any other one-sided diet. Milk, when taken alone, is not fully assimilated; about 18 per cent. of the food is lost through faulty assimilation. As much as 4 quarts of milk would have to be taken daily to thrive upon this diet. When cheese or bread is added, the assimilation is much better. The diet is then no longer one-sided, and has no injurious results; on the contrary, persons who are heroic enough to live in this way, or who are compelled by circumstances to do so, may be sure of a long life. As I have stated in my book on “Old Age Deferred,” it has happened that such persons have lived to be over 10o years old.
A one-sided diet, consisting of the same thing day after day, may also be poorly assimilated for the simple reason that the sameness of the diet does not in the least excite the appetite, and that, as a result, the psychic gastric juice as well as the juices of the pancreatic glands are excreted in very small quantities, thus causing the digestive process to suffer. It is only in certain diseases that such a one-sided diet may be of use, as, for instance, in diabetes; even here it will be found that the addition of other vegetables to a diet of potatoes or oats will cause the sugar to diminish.
For a normal person a one-sided diet is not in any way advisable, as it has the same effect as insufficient nutrition, the injurious effects of which will be dealt with in the next chapter.