The onset of infectious diseases, as pneumonia, is almost invariably associated with a complete loss of appetite on the part of the patient. Sometimes this may be ushered in with actual nausea; all such initial symptoms in acute febrile conditions must be interpreted as Nature's remonstrance against the taking of food. Any food forced down against this remonstrance, if retained at all in the stomach, will be only imperfectly digested, and as a result of the imperfect digestion, large quantities of toxic substances, products of bacterial action or of the overaction of the digestive ferments upon the slowly absorbed food, will accumulate in the intestine. These toxic substances absorbed into the blood only aggravate the condition of the patient. As a rule, the patient craves water and does not crave any form of food, even beef tea and broths. The rational dietetic procedure in all such cases is to withhold all foods for from twenty-four to seventy-two hours, according to the conditions. Satisfy the patient's craving for water by giving him all he will drink. While there is really nothing in the world better adapted to the case than pure, cold water, and in many cases nothing more craved by the patient than this drink, still, there is no contraindication to the introduction of variety into the drinks, by giving lemonade, orangeade, grape juice, Vichy or Apollinaris, or any one of a score of drinks, principally water. Even tea or coffee, hot or iced, may be used if craved by the patient. If the tea or coffee is given in a comparatively strong decoction, their stimulating effect upon the heart must be taken into consideration. The physician must decide whether or not he wishes heart stimulation. After the initial period of fasting in these cases the food should be very carefully chosen and especially adapted to the particular case. It should always be small in quantity and easily digested.

Regarding special dietaries for special conditions, more will be said in the next chapter.