Inferences

Whilst it is important that during adolescence a full ration of protein should be consumed, it is quite clear that when full growth has been attained the smallest amount of food, and especially protein, that can be eaten, consistent with health and vigour, is the best. This will, of course, vary in accordance with the occupation and habits of the individual, and should diminish as age advances. I am quite convinced that the average business man does not eat nearly so much as is laid to his credit, although it is possible that he may err in eating a little too much animal food, which is practically forced upon him by his habit of taking too little exercise. It is pretty generally recognised that the less a man eats within reasonable limits, the more healthy is he likely to be; and Rabagliati, in an effort to differentiate between functional and organic disease, declares that disease almost always begins at some point in the digestive and bloodmaking and lymph-circulating processes, i.e., that disease is a form of malnutrition. He further asserts that the particular phase of malnutrition which is commoner than all the rest put together, or at least the most common, is that which arises from excess of food.

A functional disease he characterises as one in which generally some blockage of the lymph-circulation exists in the capillary vessels lying between the veins and the arteries. When this advances a stage further, producing overgrowth of connective tissue, and an exudative process is manifest - a condition he calls initis, or congestion of the connective tissue - then organic disease is present. To determine the presence of this condition he applies pressure over the sternum, tibia, or mastoid, situations where nothing intervenes between the skin and the bone but connective tissue, and if any serious degree of pain be elicited, he concludes that excess of food is being consumed. Just how far this test substantiates his claim I am unable to say, but in my own experience my well.fed patients usually evince less sign of pain than those who are below par. I can hardly think that the physics of the circulation, either of the blood or lymph, is likely to be much disturbed until actual arterial sclerotic or other manifest changes are produced.

The Urine In Low And High Protein Diets

A comparison of the urine of those on a low.protein and those on a high.protein diet is of greater significance. Kellogg supplied such a table in his pamphlet already cited, and from this we learn that so far as one can judge the liver and kidneys in health are capable of dealing with all waste and toxic products of a high.protein ration, but just how far this is liable to interfere with their integrity it is impossible to infer.

Whilst at Yale in the spring of 1909 I had ample opportunities for interviewing those colleagues of Professor Chittenden who had been collaborating with him in his important work, and without any exception they supported his contention that a low.protein diet was ample in its supply of nutriment and satisfying in its potentiality for work.

His able coadjutor, Professor Mendel, who occupies the chair of Biological Chemistry, considered that the great experiment had at least established the protein minimum requirements of the body. As he personally was rather a hearty eater, the only way he could adopt the low-protein diet was by becoming a vegetarian, and this he did for the full 225 days. After the experiment he returned to a mixed diet with less protein than formerly, because he believes that this is the one best fitted to subserve the proper nutritive requirements of the body.

Dr. W. G. Anderson informed me that on account of increasing fatigue and loss of endurance he dropped his high-protein diet at the time of the great experiment and adopted a low-protein one, with the result that now he is in the best of health and condition. His chest capacity had increased by 2 inches, and his muscles, which I had the privilege of feeling, were as hard as iron bands.

Professor Irving Fisher stated that on account of a serious breakdown in health he was advised to adopt a system of overfeeding. Although by this means he was able to rout the disease which threatened to overwhelm him, he experienced a great lack of energy, and had no capacity for endurance. Since, however, he had adopted the low-protein mixed diet, his production of energy and capacity for endurance left nothing to be desired. He certainly looked the picture of health.

Having thus considered the evidence for and against a reduction of the protein in the standard diet, however damaging the arguments against such a proposition may appear to be, we are entitled to hold that convincing testimony has been rendered in favour of moderation. It is also pretty clear that the protein minimum is much lower than had previously been established, and sufficient warrant for cautious experimenting with minimal protein rations has been presented. During a period of compulsory sedentary employment, it is more than probable that much benefit would be obtained by diminishing the quantity of all the alimentary principles, but when the mind is free from harassing intellectual operations and physical activity is renewed, a demand for a temporary increase in the protein ration is not only normal but inevitable. The risk is that on the cessation of the muscular exertion the augmented diet may be persisted in, for in such circumstances it is indubitable that the organs of excretion are in danger of being overtaxed. The influence of the weather is likewise of great importance, a large ingestion of protein in the summer-time being accompanied by an increase in the heat production and a corresponding increase in the excretion of perspiration. Meat is therefore better avoided in hot weather, although during the winter-time it is valuable as producing an extra amount of heat.