In order to bring oneself to as limited a diet as Prof. Chittenden’s men followed, however, it would be necessary to have all food weighed so as to be sure of the correct proportions; otherwise the actual needs would not be supplied and the body would suffer. A wise provision of nature enables the body to throw off an excess of food above the body needs without injury, within limitations; but, as stated, there is no doubt that the average person exceeds these limits, exhausting the digestive organs and loading the system with more than it can eliminate; the capacity for mental work is restricted, and the whole system suffers. Prof. Chittenden’s experiments have been a wonderful revelation to dietitians and scientists. They have demonstrated beyond doubt that the average person eats much more than the system requires and thus overworks the digestive organs. [Sidenote: Mixed Diet versus a Vegetable Diet] From the fact that only from two to four ounces of nitrogenous food is required to rebuild daily tissue waste, it is apparent that this amount can readily be supplied from the vegetable kingdom, since nuts, legumes, and cereals are rich in proteins; yet there is a question whether a purely vegetable diet is productive of the highest physical and mental development. Natives of tropical climates live upon vegetables, fruits, and nuts, and it may be purely accidental or be due to climatic or other conditions, that these nations have not been those who have made the greatest progress in the world. Neither have the Eskimos, who live almost entirely upon meat, attained the highest development. The greatest progress and development, both as nations and as individuals, have been made by inhabitants of temperate climates, who have lived upon a mixed diet of meat, eggs, milk, grains, vegetables, fruits, and nuts. They have shown more creative force, which means reserve strength. The Eskimo has demonstrated, however, that an entire meat diet supplies all physical needs; the meat tissue providing growth and repair and the fat supplying all of the carbonaceous elements. The fat, as previously stated, yields more heat than starches and sugars, and Nature provides this heat for climates where most warmth is required. It may be the natural reason why natives of warm climates have formed the habit of using vegetables and grains for their heat and energy rather than meat. It is also a natural reason why man, in temperate climates, eats more meat in winter than in summer.