Diabetic B. Carbohydrates of the food, 200 grams = 820 calories.
in the urine, 180 " Available for the body, 20 grams = 82 calories.
As the sugar which escapes in the urine is lost to the economy, the same food has a very different calorie-value for the healthy and for individual diabetics. For instance (see the example given on page 87) : 150 grains albumin = 615 calories.
100 " fat = 930 " 200 " carbohydrate = S20 " Total 2,365 calories.
Value of this diet for the healthy individual, 2,865 calories.
" " " " " Diabetic A. 2,365 — 82 = 2,283 calories.
" " " " " Diabetic B. 2,365 — 738 = 1,627 calories.
This presentation shows that the depreciation of the nutritive value of the food by reason of the sugar waste, varying in each indi vidual case, is to be taken into consideration in prescribing the quan tity of nourishment; it teaches further that, the greater is the inten sity of the glycosuria, the more must the patient look for the support of his strength to other nutritive materials, proteids, fats, and, in moderate quantities, alcohol.
We may also remember that certain forms of carbohydrates are more suited to the diabetic's use than are others,—for example, fruit sugar, milk sugar, and in certain quantity also cane sugar. In practice, however, the advantage derived from their use does not meet our theoretical expectations. In mild forms of glycosuria oc curring in elderly people very little depends upon the variety of the forbidden carbohydrate, and in the severer forms the gain in avail able carbohydrates is only a little greater, even when large doses of fruit sugar, milk sugar, and the like are given, than with the use of bread and farinaceous foods. The disadvantage of glutting the or ganism with carbohydrates might easily overbalance the gain in utilizable nutritive material. On the other hand, in cases of moder ate severity and in mild forms of glycosuria in young people, these special forms of carbohydrate, with milk sugar at the head, seem to me to be worthy of the practitioner's special consideration (see be low, iu the section on "Milk-Cures").
c. The Injuriousness of the Carbohydrates.--Under certain circum
stances carbohydrates are injurious to the sufferer from diabetes. It will be well to define these circumstances more exactly, as many confus ing opinions have been expressed on this point.
It is not alone that carbohydrates are of little value in the severe forms of glycosuria, their ingestion being comparable to pouring water into a cracked vessel, but large quantities are even harmful in grave cases. Many attribute the injurious consequences of the inges tion of carbohydrates to the increased percentage of sugar in the blood, and refer the secondary affections of all kinds, occurring in the diabetic, to this condition (cf. p. 100). I have already said that this hypothesis is anything hut well founded. But it is a fact that diabe tics who indulge freely in carbohydrates, without regard to the severe glycosuria present, suffer in the course of time from a markedly de creased tolerance of starch and sugar. They react to the same amount of carbohydrate taken in time food by a more intense glycosuria than before. This observation can be easily made in almost all severe eases, and the reverse of it, an improvement of the glycolytic func tion following a reduced ingestion of carbohydrates, may also be adduced in support of this statement. Tlii fact is explained by the general biological experience, which has been demonstrated with special clearness by F. A. Hoffmann, that functionally weak organs (in this case the sugar-consuming cells) are injuriously affected and made yet weaker if continuously spurred on to overwork. Rest, not exercise, is for them the proper treatment.
From this point of view it would be best in cases of considerable or extreme severity (tolerance = 0 gm. or < 0 gm. carbohydrate) to strike the carbohydrates entirely out of the food ; it is only a con cession which we make to other evils when, in these cases, we allow a certain amount of carbohydrate either temporarily or permanently. The reasons which constrain us to yield this point will be considered in the next section.