The adoption of dietary habits that aim to accord with the physiological requirements of the body does not compel a crucifying of the flesh or a disregard of personal likes and dislikes. A reasonable intelligence combined with a disposition to exercise the same degree of judgment and care in the nutrition of the body as is expended on other matters, of no greater importance, pertaining to the individual, to the household, or to business interests, are all that is needed to bring about harmony between every-day dietary habits and the nutritive requirements of the body. There is no occasion, unless one finds pleasure and satisfaction in so doing, to resort to a limited dietary of nuts and fruits, to become an ardent disciple of vegetarianism, to adopt a cereal diet, to abjure meats entirely, or to follow in an intensive fashion any particular dietary hobby, except so far as may be necessary to insure an adequate amount of non-nitrogenous foods to meet the energy requirements of the body without unduly increasing the intake of proteid or nitrogenous food. Naturally, a man leading a life of great physical activity with the consequent demand for a large energy-yielding intake will be compelled to resort largely to vegetable foods, rich in starch and poor in proteid, or to eat largely of fatty foods. Reliance on meats and animal foods in general, under such conditions, would plainly involve a high proteid intake with a consequent high nitrogen metabolism, with the chance that even then the energy requirement would not be fully met. In view of all that has been said, reinforced by the various facts brought forward as evidence, we must recognize the value of the non-nitrogenous foods as a source of energy, and this means plainly food from the plant kingdom. In any rational diet, vegetable foods of low nitrogen-content must predominate, while animal foods with their higher nitrogen values must be greatly subordinate in amount, if the nitrogen or proteid metabolism of the body is to be maintained at a level commensurate with true physiological requirements. But there comes the ever-recurring question, Are the lower proteid standards quite safe to follow? Are we warranted in turning aside from the teachings based on the habits and customs of mankind? Many reasons have already been presented which seemingly justify an affirmative answer, while the experimental results and the observations on various groups of people, covering years of time, speak with no uncertainty regarding the element of safety, and indicate clearly that the absolute proteid requirement of the body is quite small; much smaller indeed than the amount of proteid food consumed by the average individual would seemingly imply.