By choosing suitable pulses, nuts and cereals, a diet can be devised which is devoid of animal food and not very bulky. The nuts would have to be relied on for fats. Vegetarian, fruitarian, or nutarian diets are much better when combined with eggs, milk and milk products.
Animal proteins appear to develop mental energy and increase the bodily resistance to disease better than vegetable ones. The meat-eating races are physically more powerful, more intellectual and more progressive than others. Carnivorous animals seem to have a vital energy which is more alert than that of the herbivorous and cereal feeders.
The digestibility of foods depends on composition and bulk. A diet of bread and vegetables is more bulky than a mixed diet and mechanically interferes with digestion. Green vegetables, many tubers and most fruits have been shown to contain little nutriment in comparison with their bulk. Cellulose is indigestible, innutritious, and interferes with the mixing of the digestive juices with the nutritive materials in the food. Mechanically, a large amount of material has to be dealt with, driven through the alimentary canal, and got rid of. Hence arise the large abdomens of vegetable feeders, e.g. cattle, horses at grass, etc., the " potato-belly '" of the Irish, and the large stools. The increased bulk needs increased peristalsis, a liberal blood and nervous supply to the viscera, and an undue expenditure of nervous energy on the digestive processes. To compensate for slow digestion herbivorous animals have huge caecums and a longer alimentary canal than carnivora and mixed feeders.
Absorbability varies inversely as the amount of cellulose present and directly with the quality of the cooking. An American observation on a diet of fruit and nuts showed that the following percentages were absorbed : protein 82.5, fat 86.9, non-nitrogenous substances 96. Tofu, a Soy bean preparation made in Japan, consists chiefly of bean protein precipitated in combination with magnesium and calcium salts, and has a co-efficient of digestibility for protein of 96, fat 97, carbo-hydrate 88 per cent. These must be compared with the absorbability of (1) Animal Diet: protein, 100; fat, 80-90; (2) Mixed Diet: protein, 92.5; fat, 95; carbo-hydrate, 97.5. The results are in favour of the mixed or animal diet, but depend partly on the preparation of the food. Prolonged vegetarianism does not improve the absorptive capacity and the waste of nitrogen is considerable, much being lost in the faeces.
The cost of cooking is a serious item in the vegetarian diet. Although many of the foods are cheap, in comparison with animal foods, they may contain so little nutriment that from the point of view of nutritive value they are very expensive. Cooked celery and onions contain hardly any nutriment. The cost of cooking and the fuel bill is very much greater.
Protein food is essential for growth during early life, and the effect of deficiency is shown in the relatively stunted development of the poor as compared with those who obtain a proper food supply. That animal protein is the proper kind to take is suggested by the fact that the proper diet for the infant is the mother's milk or that of some other animal. Under a system of universal vegetarianism it has been shown that the supply of milk would be small and quite out of reach of the poor. Later on in life it is probable that quite two-thirds of the necessary protein can be taken in vegetable forms.
The lack of resistance to disease is obvious when the diet is devoid of sufficient protein or of animal protein. Thus, phthisis and epidemics are common among the Irish poor and the lower classes of large towns. Possibly this would not be so evident if the diet could be enriched in protein and fat by means of pulses and nuts. The protein value of a fruit and nut diet is small. Jaffa in California found that in two subjects 8 grammes of nitrogen, and in two others 10 grammes, were sufficient to maintain nitrogenous equilibrium. Such figures have been found by Chittenden sufficient for all classes of people and, if we accept his conclusions, the amount of protein required for the daily ration can be reduced to one-half the accepted standard. The amount varies in different individuals and in the same individual at different times. Further, it is doubtful whether it is wise to live on a minimum diet of protein food, for protein tissues are only built up slowly from the protein consumed, and loss of nitrogen is only slowly replaced. Nevertheless, the subjects of Jaffe's observation had maintained excellent health for years, though they did not look robust.
A fruitarian diet is very suitable during an acute illness, such as pneumonia, and should consist of: -
Milk, 2 oz. every 2 hours; cold, warm, never boiled; diluted The juice of grapes, oranges and pine-apple; grapes, bananas cooked apples, etc.
White of egg. Egg lemonade, i.e. the whole of one egg, half a lemon, half a pint of water, and sugar.
The ordinary fruitarian diet of fruit and nuts must be modified in accordance with the foods in season and their composition. Nuts supply the protein and fat. Chestnuts and bananas provide the carbo-hydrates. All fruits will yield some carbo-hydrates and protein. Acid fruits should be taken in moderation. Stone fruits sometimes disagree. Lemon juice should be used in preference to vinegar for salads, as less likely to cause dyspepsia. The excess of potassium salts must be counteracted by common salt. Nuts should be well ground up in a nut mill. Food should be eaten slowly and not more than three meals a day taken. Two meals are sufficient. It is not advisable to omit milk.
Chittenden made observations on a man, aged sixty-three, a fruitarian for 20 years, who did a little gardening and walked four to eight miles daily. At times he took a little vegetable and cereal food. The average daily intake of fruit and nuts yielded protein 40, fat 54, carbo-hydrate 286 grammes, crude fibre 56; calorie value 1,700.
First meal: Oatmeal, 227 grammes; butter, 10; sugar, 35; milk, 60, coffee, 210. Second meal: Macaroni, 142; cheese, 10; bread, 71; sweet potato, 119; milk, 250. Third meal: Bread, 80; butter, 20; mashed potato, 176; string beans, 77; apple-pie, 82; milk, 250. Total nitrogen, 10 grammes. N-excretion in urine 8.5 grammes. Calories over 2,000.
Caspari and Glaessner found the nitrogen was 8.27 grammes, fat 218.9 grammes, and the calorie value 4.554, of a vegetarian diet which consisted of coffee 20, sugar 40, grapes 230, nuts 113, oil 154, potatoes 1,005 and carrots 30 grammes.
Fletcher, weighing 57.3 kilos, took ten meals daily, and gained 0'2 kilos in spite of considerable exercise, on a diet containing 1,300 calories of heat. It consisted of potatoes 159.4, eggs 124.7, milk 710, cream 237 grammes. While under Chittenden's observation and weighing 165 lbs. he took a diet of protein 45, fat 38, carbo-hydrate 25.3, calories 1,600, in the shape of milk, cereal food and maple sugar. Weight and nitrogenous equilibrium were maintained and he was capable of hard exercise. Such cases support the contention that the limitation of the diet is one reason of the success of vegetarianism and allied methods of feeding.
These diets are suitable for the constipated and the corpulent, because of the large residue and the small nutriment. If they do not remedy the constipation they do harm by increasing the amount of waste matter. They are sometimes useful in the rheumatic and gouty diatheses; for migraine, recurrent headaches, neuralgias; for neurasthenia, epilepsy and hysteria, if dependent on intestinal toxins derived from meat; in nervous insomnia, exophthalmic goitre, chronic alcoholism, functional cases of dyspepsia and intestinal disorders; and in some skin diseases.
Diets of this nature should be commenced gradually and may be continued for six weeks at a time, if beneficial, and in a more or less modified form for the remainder of life.