The vexed question as to the advisability of drinking fluids at meal times is one which amateur dietetic reformers invariably answer in the negative. At first sight this course of action is apparently justifiable, because we have already seen that practically no fluids are absorbed by the stomach wall, but are rapidly ejected into the duodenum in advance of the solid food. In a healthy individual this is likely to have no deleterious action on the process of digestion, but the stomach of the average town-dweller is not provided with a very strong musculature, and so the fluids are retained too long, diluting the digestive juices, delaying digestion, and favouring an increase of microbic putrefaction. Hence the average City man has solved this question for himself by limiting his consumption of fluids at meal times, especially at such meals where he is unable to rest in a reclining posture. For this reason his midday meal is usually restricted to a small snack, and he imbibes his fluids in the shape of weak tea in the afternoon and at his more leisured evening meal.

From the results of an experiment on the metabolic influence of copious water-drinking with meals, it would appear that in those cases in which the stomach can sufficiently deal with the increase of fluid, decided advantages accrue from its consumption. The subject of the experiment was a young man weighing 71 kilograms, who was placed on a uniform diet capable of maintaining him in a condition of "nitrogen equilibrium." For six days 900 c.c. of water were ingested daily, one-third of this amount being taken with the meals, and then for five days more 1,000 c.c. of water were added, and equally distributed over the various meals. At the end of this time the fluid was again diminished to the original amount for a further period of eight days.

As might have been anticipated, several facts previously known, such as an increase in the body-weight and an increased excretion of urinary nitrogen, doubtless due to a "washing out" of the tissues, were corroborated. One would hardly have expected, however, to find a decreased excretion of faeces and faecal nitrogen, nor a decrease in the quantity of bacteria excreted daily, although the two facts are distinctly correlated. The output of ammonia was increased, which was interpreted to indicate an increased excretion of gastric juice, and doubtless was the determining factor in the more economical utilisation of the protein constituents of the food. There was a decreased excretion of creatinin and a coincident appearance of creatin in the urine, and it is suggested that this indicated a stimulation of the protein katabolism by the copious water-drinking.

As it is quite exceptional for creatin to be present in the urine without the existence of some pathological process, its appearance is explained by the statement that the water had caused a "partial muscular disintegration, resulting in the release of creatin, but not profound enough to yield the total nitrogen-content of the muscle. The output of creatin is therefore out of all proportion to the increase in the excretion of total nitrogen."

Haas has shown in experiments on man that there are two well marked curves of nitrogen elimination after a breakfast of milk, bread, butter and cheese: one in the second hour, due to the washing out of nitrogenous end-products in the tissues by the early absorption of liquids swallowed at the meal, the other in the fifth hour, due to the absorption of food protein. If the tissues have been depleted of their urea by tea-drinking prior to such a meal, the primary curve is much lower, and the total elimination of nitrogen decidedly diminished.

From the findings above detailed it is concluded that many desirable features attend the consumption of a large amount of water with meals, and no valid reason exists as a contraindication to its use. In all probability the only objection which can be advanced in opposition to this statement is the very cogent one that the habit of drinking largely at meal times is almost always accompanied by a tendency to bolt the food without careful mastication, and even in strong young subjects a continuance of this reprehensible practice must eventually induce a condition of dyspepsia incompatible with the existence of a powerful musculature in the stomach. Without advocating the exclusion of all fluids at meal times, it is injudicious to recommend more than a very modest consumption, leaving the greater quantity to be partaken of between meals, or first thing in the morning and last thing in the evening.

The moderate drinking of fluids during or shortly after meals is especially indicated in cases of pyloro-spasm, either due to hyperchlorhydria or excessive organic acidity, thus preventing undue distension of the stomach wall. In the former case, non-effervescent alkaline table-waters are most suitable, while in the latter, where hypochlorhydria usually exists, plain water, by simply diluting the hyper-acid contents, allays the spasm and enables the stomach to be more easily emptied.