Diabetes is a true disease of disturbed metabolism. While digestion and absorption go on in a normal way, the assimilation of foods is at fault. In mild cases, the carbohydrates alone cannot be utilized. Instead of burning up and generating heat for the body economy, they are eliminated from the system in the form of sugar with the urine. In the severe forms, the proteins are split up partly into carbohydrate material, which latter again is not burned up but is excreted as such. In the still severer forms, fats (the third nutritive group) are likewise broken up into acid radicals, which again do not oxidize to their ultimate products, but circulate for a while in the blood stream as such, and are partly excreted with the urine (acidosis). The glucose, as well as the acid products, when accumulated in the system, act as irritants, producing abnormal conditions which give rise to the development of various diseases.

1 Read before the N. Y. Medical Union on January 23, 1917.

The treatment of diabetes, therefore, has for its object at first the freeing of the organism of both sugar and acids. The management of this disease, - in attempting to keep the body free from the above metabolic defects, - is then a question of diet, and this has played the greatest part in the treatment of this condition almost since the discovery of the disease. Rollo, in 1796, introduced an animal diet as a cure for diabetes, and this treatment has been more or less rigidly adhered to by most clinicians for over a century.

Bouchardat and Cantani recognized the evil results of a too liberal protein diet, and introduced green vegetables as an important factor in the treatment of this disease. Naunyn,1 one of the greatest investigators of diabetes, likewise recognized the utility of green vegetables in the dietary regime of diabetes, and discovered the fact that fast days produce beneficial results, by not only clearing up the resistant glycosuria and improving tolerance, but also by at times warding off comatose conditions.

1 Naunyn: Der Diabetes Mellitus Wien, 1906.

Von Noorden corroborated Naunyn's statements, and made use of fast days, especially when acidosis was present. He noticed the striking effect that fasting had upon the fall of acetone. In severe cases of diabetes with acidosis he instituted one fast day every week, with excellent results. Fasting in the treatment of diabetes has been frequently practised by Guelpa1 of Paris. He insisted that the patient should fast for three days or more, with a bottle of Hunyadi Janos water each day, followed first by a milk and then a vegetable diet, - with occasional repetition of the fasting and purging. In mild cases, Guelpa noticed great benefit from this treatment.

While formerly most clinicians laid much stress upon keeping the organism of the diabetic patient in good condition and well nourished,- it was believed to be of essential importance to look out for a sufficient amount of food (see Lecture VIII), - Allen2 was one of the first to break away from this maxim and to rather lay the greatest stress upon keeping the diabetic patient free from sugar, - even, if necessary, at the cost of a loss of strength and body weight. Allen's ideas were quite revolutionary, and while his treatment was not new in every feature, it represented on the whole a great innovation and marked a long step in advance. From my own experience I can fully corroborate the statement which Joslin1 uttered in 1915: "It is no exaggeration to say that the advance in the actual treatment of diabetes mellitus during the twelve months just passed has been greater than in any year since Rollo's time".

1 Guelpa: British Medical Journal, 1910, ii, p. 1050.

2 F. M. Allen: "Studies Concerning Diabetes, Journal American Med. Association, 1914, p. 939.

F. M. Allen: "The Treatment of Diabetes," Boston Med. & Surg. Journal, 1915, p. 743.

Before outlining Allen's plan of treatment, it will be well to state that at present the view prevails that diabetes mellitus is a disease caused by a disturbed function of the internal secretion of the pancreas, the islands of Langerhans being principally involved. In testing the experiences gained by noted clinicians in the field of diabetes, Allen made numerous experiments upon animals in which the pancreas had been to a great extent extirpated. He found that if the pancreas remnant in operated animals is about one-tenth, the diabetes is permanent, even on a meat diet, and usually ends fatally.

1E. B. Joslin: "Present Day Treatment and Prognosis in Diabetes." Amer. Jour. of Med. Sciences, 1915, p. 485.

A few days of fasting at the outset, however, will produce sugar freedom. If the diabetes is allowed to continue longer, a much longer period of fasting may be necessary for sugar-freedom, or it may be impossible to obtain it. If, after obtaining sugar freedom, feeding of protein and fat is begun very cautiously, - in quantity only enough to maintain the animal in its thin condition, - such animals remain free from diabetes. Increasing the weight of such an animal very soon produces glycosuria, which can be checked by renewed fasting. Animals made diabetic by carbohydrate diet, act in a similar way, - i.e., they soon become sugar-free, after starving (F. M. Allen: Studies concerning Diabetes).

Allen then gives the following rules: Make patient sugar-free by fasting. Then gradually increase the food, according to the tolerance, and keep him steadily free from sugar. A loss of weight at first, - especially in a not too greatly emaciated individual, - is desirable. Never give a too high calorie diet, nor give too much protein. (Allen allows 1 gram of protein per day to a kilogram of weight). If the patient has lost much in weight, he may be allowed, by increasing the fat in the food, to regain part of it, provided that no sugar reappears in the urine. As soon as the latter occurs, he must return to a lower calorie diet.