the daily food need not exceed 2,800 calories. As compared with the ordinary statements of the body's needs, this means a saving of one half in the amount of proteid food and about one fifth in the amount of non-nitrogenous food daily. That these smaller amounts of food are quite sufficient to meet the needs of the body is indicated by the condition of the subjects after many months of living at these lower levels. Especially noticeable, because at that time wholly unexpected, was the decided gain in bodily strength and endurance manifested by all the subjects of experiment. This gain was spoken of as gain in "total strength," but the element of endurance was incorporated therein, since the final product[1] was a compound of the dynamometer tests of individual muscles and the number of times the individual could pull up and push up his body on the parallel bars. The natural interpretation of the results obtained was that the increased muscular efficiency was a direct or indirect result of the lowered proteid metabolism of the body. In other words, it might be reasoned that the smaller consumption of proteid food was a nearer approach to normal conditions, and as a result there was manifested an increased muscular efficiency. However this may be, bodily strength and endurance were certainly increased, and the question naturally arises, will this improved state of the body continue for any length of time under such conditions of diet? In other words, may we expect to find an improved physical condition of the body in following habits of life which seemingly accord more closely with true physiological needs, avoiding that excess of food intake that the common practises of mankind sanction?
One of the first subjects experimented with by the writer was Horace Fletcher, who in 1903 spent several months in our laboratory[2] and was at the same time carefully tested by Dr. William G. Anderson, director of the Yale Gymnasium, as to his physical condition. For some five years Mr. Fletcher had practised a certain degree of abstinence in the taking of food with, as he believed, important economy, i. e., great gain in bodily and mental vigor and with marked improvement in his general health. He found that under his new method of living he was possessed of a peculiar fitness for work and with freedom from the ordinary fatigue incidental to extra physical exertion. In the laboratory observations made at that time, it was found that he was not metabolizing more than fifty grams of proteid per day, while at the same time his body was essentially in a condition of nitrogen equilibrium. Dr. Anderson, as the result of his observations on Mr. Fletcher, concluded that, considering his age, he had never seen an individual able to work in the gymnasium with fewer noticeable bad results, since he was able to do the work of trained athletes and not
