activity. This we have sought to ascertain by our studies of the past five years, and confidence in our results is augmented by the fact that when living on a lower level of proteid consumption bodily strength and endurance are unquestionably increased; muscular fatigue and soreness as concomitants of severe or prolonged muscular effort diminish or are wholly wanting; thus raising the suggestion that under true physiological conditions the muscles of the body are capable of more prolonged effort, and with greater freedom from disagreeable after-effects than when the system is charged with an excess of nitrogenous and other waste incidental to large intakes of proteid food. In other words, consumption of proteid food in closer harmony with the true needs of the body is accompanied by a smoother and more efficient working of the bodily machinery; less friction and better results follow a daily diet in which excess is avoided and the intake made to correspond more closely with physiological requirements.
Those who are skeptical of the real value of a relatively low intake of proteid food frequently acquiesce in the general statement that as a physiological experiment it may be quite true that equilibrium, physical vigor, efficiency, etc., can be maintained by a smaller amount of proteid food, but they are inclined to the view that in the long run more abundant supplies of nutriment will be demanded in harmony with the ordinary customs of mankind. This is a reasonable objection, and one that time only can answer. It is quite possible—though not very probable—that an experiment of several years' duration even may fail to show certain deleterious effects which eventually may manifest themselves, assuming that the body does actually need more proteid food than our experimental results imply. This may be a purely theoretical objection, but it is one that is deserving of some consideration, since it is unquestionably true that there are many factors in the broad subject of nutrition not yet fully understood, and there are many phases of proteid metabolism not wholly clear. So far as any experimental evidence is concerned, however, there is nothing, in the writer's opinion, that can be construed as giving weight to this objection. Neither are there any observations bearing on the customs or habits of peoples or communities that can be adduced in favor of possible danger to the individual from a continued intake of proteid food in harmony with our experimental data; certainly none that is not equally susceptible of plausible explanation on some other ground.
As has been stated in another place,[1] a daily intake of GO grams, or two ounces, of proteid is quite sufficient to meet the needs of a man of 70 kilograms body-weight, and this without increasing unduly the amount of non-nitrogenous food. In fact, for a man of the above weight doing an ordinary amount of work, the total calorific value of
- ↑ "The Nutrition of Man," p. 272.
