Value of a mixed diet. 

The question of a mixed diet versus the vegetarian diet revolves around the amount and kind of protein which most adequately meets body needs. From earliest times man has thrived on a mixed diet. Nature has equipped him to do so. The kind of teeth and the nature of his digestive apparatus clearly indicate the suitability of a mixed diet. Regarding the value of a mixed diet, McCollum says: "In general, a vegetable diet will be markedly improved by the inclusion of muscle tissue meat, and more so by the addition of the glandular organs, but even these features of the subject are not from the standpoint of good nutrition the most important. It is scarcely practicable for man to eat enough leafy foods to enable him to succeed with the strictly vegetable diet. The limiting factor is the amount of leafy food which can be consumed."1 

Vegetarian diet. 

It is possible to live on a strictly vegetarian diet but it is not easy to do so and maintain the body in the highest degree of efficiency. It is often shown that the so-called vegetarian diet is supplemented with animal protein in the form of milk and eggs. McCollum says: "The diet which is strictly vegetarian will practically always be of relatively low protein content. The addition of even small amounts of meat, even of the muscle variety, will be very valuable when such a regimen is adhered to. Eggs, because of their relative richness in fat-soluble A and water-soluble B, will be even more effective supplements, and the same statement will apply to the consumption of small amounts of glandular tissue. Even small amounts of foods of animal origin will tend, therefore, to enhance the diet of one who is forced by economic reasons, rather than by ethical reasons, to subsist in the main upon vegetable foods. In another connection we shall present data showing that a diet too low in protein or in which the proteins are of a poor quality, exerts very deleterious effects upon experimental animals." 2 

The objection of vegetarians to a meat diet are not valid, as one writer points out: "History does not indicate that the eating of meat has the debasing effect, physical or moral as feared by them (vegetarians). The most vigorous, intellectual and highly civilized people the world has known have eaten meat."3

1 MCCOLLUM, E. V., The Newer Knowledge of Nutrition, 2nd edition. 

2  , The Newer Knowledge of Nutrition, 2nd edition.

3 MCLESTER, JAMES S. , Nutrition and Diet in Health and Disease.