So far nothing has been said in regard to the water intake. This question has already been discussed at length in a previous volume of this collection (No. IV). I have for a long time been combating the view originally advanced by Oertel and Schweninger that the reduction of the water intake in creases the oxydation of fat and in this way becomes directly operative as a means to reduce fat; nowadays this opinion is hardly discussed seriously. The consumption of energy is in no way increased by the restriction of water; this is demonstrated by convincing experiments in animals, in healthy and sick individuals. It remains undetermined whether extreme restriction of water, such as one would actually never encounter, might not yield a different result, but from a practical standpoint this is without importance. Recently E. Heilner has shown that, per contra, the abundant ingestion of water increases fat catabolism and the transformation of energy in general. This corresponds very well with the experiences in animals recorded by Henneberg (Congr. for Internal Med. Wiesbaden, 1885), live stock men having found that the administration of abundant water renders it very difficult to fatten animals. On the other hand it is no doubt true that restriction of the water intake, everything else remaining equal, produces a loss of fat. This effect is indirect. Many people spontaneously suffer a loss of appetite if they are allowed little to drink, especially if the ingestion of liquids is forbidden during meals. In such individuals, therefore, drink restriction constitutes a convenient method of preventing polyphagia and hence incidentally of combating obesity. All people, however, do not react in this way; for some persons eat just as much despite the reduction of liquids, and such people consequently do not become thinner; others, again, suffer a loss of appetite in the beginning, but soon become accustomed to the new régime and again eat more abundantly, so that the initial loss of weight that was warmly welcomed when it occurred, is soon regained. At all events, this simple means of attaining the desired end is worthy of trial in any case. Only in the uric acid diathesis and in cases showing a tendency to stone formation (gallstones!) this measure might turn out to be precarious. Obese diabetics and neurasthenics, also, tolerate the reduction of the liquid intake very badly.

Personally I only employ water restriction if there are complications about the heart and arteries. Here, however, these latter complications and not the obesity become the determining factor. Especially in cases with very high blood pressure is this method of value.

Otherwise I permit free ingestion of liquids in reduction cures in the form of plain drinking water, mineral waters, tea, coffee, fat-free meat broth. The loss of flesh is not impeded hereby, and a great favor is at the same time rendered these patients who are compelled to suffer manifold deprivations in other directions.