The importance of diet in tuberculosis is universally admitted. No matter how good the climatic conditions under which a consumptive may live, he will not improve if he does not have suitable aliment. The prognosis of a given case must depend largely upon the ability of a patient to eat and to assimilate food.

The object of dietetic treatment is to maintain strength and to develop resistance to the infection and to the spread of tuberculous lesions.

If tuberculous patients are classified accordingly as their power to digest and to assimilate food is impaired, they can be placed in three categories. One embraces those who have good appetite and ability to digest and to utilize foods. Another contains those whose need of food is increased because strength and endurance are being sapped by constant fever, but whose ability to digest and to appropriate nourishment to their needs is variously impaired. A third class includes the cases complicated by indigestion, the symptoms of which are poor appetite, a coated or, rarely, a raw, tongue, slight flatulence, constipation, continued loss of flesh and of strength. It is rare that pain, nausea, vomiting, and other symptoms of acute or subacute gastritis are observed.

Patients belonging in the first category need little guidance as to their diet. They may be permitted to eat all kinds of food that they enjoy. They should, however, be counseled to preserve their good appetite and digestion by eating food that is simply prepared and least liable to check digestion or to ferment in stomach or bowels.

They should be urged to eat as much as they can without overtaxing the organs of digestion. Just what this amount is, the physician should endeavor to ascertain. It is important to eat so as to increase weight. Fats, oils, and carbohydrates must be prescribed generously, but meat or albumins must not be neglected. These patients must be cautioned, the same as all others, not to swallow their sputa, which is often a cause of disturbed digestion, and sometimes of tuberculous infection of the intestines. When considerable quantities of mucus and mucopus are swallowed, they interfere mechanically with the digestion of food by enveloping it and separating it from the digesting juices. They also partly neutralize the acid gastric juice, or, when digestion is weak, they may do so completely. In these ways sputum when swallowed helps to produce indigestion or gastritis.

For patients of the second and third categories food must be prescribed with care. Its character and quantity must be governed by the digestive capacity of each individual. As a rule, appetite is considerably diminished, and less food is taken than in health. Patients often say that their appetite and digestion are good because they do not experience subjective symptoms of indigestion and they have eaten little for so long that they think it is natural. If they are carefully questioned as to the amount that they eat, its smallness will be demonstrated and they will modify their first statement by saying that it seems to be all that they need in their emaciated state. Others are painfully conscious of their poor appetite. This is especially true of those who suffer from chronic gastritis.

Febrile patients should be fed as generously as possible. As the fever of tuberculosis is intermittent or remittent, the heartiest meals can best be given during the hours of remission. When fever does not rise high or become manifest early in the day, noon is the best time for a hearty meal. If there is pyrexia at this hour, breakfast must be made the heaviest meal of the day. A glass of hot milk or cocoa, or coffee with an abundance of milk, should be given when a patient first awakes. Breakfast should come between seven and ten, when the morning coughing spell is over, if there is one. About three in the afternoon a glass of milk, a little meat-juice on cracker or bread, bouillon, chicken, or other broth, Mellin's food, malted milk, a custard, or egg lemonade should be taken. Supper should be comparatively light. At bedtime a glass of hot milk should be taken. When patients are feeble, they should be given a little food at two or three in the morning. As the patient's appetite is liable to be wanting or capricious at luncheon time, it is best to vary his menu for this meal as much as possible. Nor should the patient know what his lunch is to be, until it is brought to him. The quantity should be moderate, so that it will be quickly consumed. So long as digestion is fairly good, breakfast and dinner may consist of the foods usually eaten at those times. The patient is sure to eat sparingly. If he is permitted to eat as others do at these mealtimes, he will not grow restive under guidance, as he is inclined to do. At supper time, when his temperature is considerable, the simplest foods, and often soft and liquid foods with agreeable fruits, should be prescribed.

When patients have gastritis, they must be studied with care as individuals, and food adapted to their various powers of digestion. Appetite is not a guide as to the ability of a patient to digest and assimilate food. Debove showed this in his early experiments with forced feeding of phthisical patients. He demonstrated that often a gain in weight will be made and maintained if sufficient food is forced into the stomach of patients who lack appetitie or suffer with anorexia. The appetite of such patients is so poor and so capricious that it is difficult to prevent slow, steady emaciation. Usually, under these circumstances, the quantity and functional power of gastric juice are lessened. Food is therefore best given in moderate quantities and in a soft or liquid condition. A rest of an hour should be taken before each of the three heartiest meals. Freedom from anxiety and care should be procured for these patients, if possible. A feeling of hopefulness should be encouraged, not of immediate recovery, but of possible, gradual, although slow, improvement. A change of scene, of nurses and attendants, often promotes better appetite and digestion.