This is the title of a recent work by Prof. Russell H. Chittenden, director of the Sheffield Scientific School of Yale University. Prof. Chittenden's experiments were instituted chiefly to find out whether or not we were eating too much of proteids in our daily meals, whether or not we were eating too much of meats, milk, eggs, and vegetables, such as beans, peas, oat meal, etc., all of which carry within themselves as food for man large percentages of the proteids, the food which builds up our tissues and at the same time affords energy, this energy, of course, being much less than that afforded by the sugars and starches, the real energy-producing foods.

Before going further, let us look at Carl Voit's diet standard, the one generally accepted: For an adult man of average bodily weight, say one hundred and sixty pounds, doing moderate muscular work, he allows daily 118 grams of proteid or albuminous food, of which 105 grams should be absorbable, 56 grams of fat, and 500 grams of carbohydrates, with a total fuel value of over 3000 calories, in order to maintain the body in equilibrium.

Let me take up the matter of what we may look upon as one-sided diets, compared with Voit's diet just given for an able-bodied man. Here the element of safety to the individual and such matters come in. Hirschfeld, experimenting on himself, maintained nitrogenous equilibrium on 7.5 grams of nitrogen per day. He was twenty-four years old and weighed about one hundred and sixty pounds. Kumagawa, a Japanese, for nine days consumed 8.75 grams of nitrogen per day and got a plus balance of 4 grams proteid per day. His diet was purely vegetable, presumably most of it rice, as prepared by the Japanese, which, from less cleaning, is higher in nitrogen than our rice. Another Japanese study showed that on a strictly vegetable diet containing 11.34 grams nitrogen there was a daily loss to the body of 1.16 grams nitrogen. On adding fish to the diet, giving 17.48 grams nitrogen, nitrogenous equilibrium was established. Other investigators, however, have found no difficulty in keeping up nitrogenous equilibrium on a lower amount of nitrogen in the diet. These examples, Chittenden remarks, surely warrant the question, How far are we justified in assuming the necessity for the rich proteid diet called for by the Voit standard? There is a constant temptation to increase the daily ration, and there is an almost universal belief in the efficacy of a rich and abundant diet to strengthen the body and to increase bodily and mental vigor. Chittenden asks the question, Is there any justification for these beliefs? He answers, None, apparently, other than that which comes from the customs of generations of high living. Voit has clearly emphasized the general principle that the smallest amount of proteid, with non-nitrogenous food added, that will suffice to keep the body in a state of continual vigor is the ideal diet. We know that proteid decomposition products are a constant menace to the well-being of the body; any quantity of meats, and such, beyond the real requirements may prove distinctly injurious. We see the evil effects of uric acid in gout, but there are many other nitrogenous waste products of proteid katabolism which, with excess of proteid food, are liable to be unduly conspicuous in the fluids and tissues of the body, and may do more or less damage prior to their excretion through the kidneys. Further, it requires no imagination to understand the constant strain upon the liver and kidneys, to say nothing of possible influence upon the central and peripheral parts of the nervous system, by these nitrogenous waste products, which the body ordinarily gets rid of as speedily as possible. They are an ever-present evil, but why increase them unnecessarily? This question brings us back to the starting point, What is the minimal proteid requirement for the healthy man, or, rather, how far can we safely and advantageously diminish our proteid intake below the commonly accepted standards? The question of safety is a pertinent one.

Munk found that dogs fed on low proteid diet, but with abundance of carbohydrates and fat, after several weeks showed a loss of power of absorption from the alimentary tract, dependent not alone upon a changed condition of the epithelial cells of the intestine, but also upon a diminished secretion of the digestive juices, loss of body weight, strength, and vigor, followed speedily by death. If these results were really due to a low proteid diet, they suggest a grave danger which must not be lightly passed by. These dog experiments of Munk have been disproved by experiments on human beings by Albu and others. It has been suggested that when living at a fairly high proteid level the body is more resistant to disease and other strains than when the proteid level is low. There is another side to the question, - viz., the possible danger to the body from the physiological action of the larger amounts of nitrogenous waste products which result from an excess of proteid food, and which float about through the system prior to their excretion.

We must not overlook the great loss of energy to the body, Chittenden pertinently observes, in handling and getting rid of the surplus of unnecessary food of whatever kind introduced into the alimentary tract, to say nothing'of the danger of intestinal putrefaction and toxaemia when from any cause the system loses its ability to digest and absorb the excess of food consumed. Further, the possible strain on the kidneys and other organs must not be overlooked. Hence we may well question on which side lies the danger. To an unprejudiced observer, one not wedded to oldtime tradition, it would seem as if great effort was being made to sustain the claim of high proteid intake. It is surely well to be careful, but certainly it is not necessary to magnify imaginary dangers to the extent of suppressing all efforts towards the establishment of possible physiological economy. Let us study well these dangers.