Malnutrition is caused mainly by errors in eating, sedentary habits, and lack of fresh air. The remedy, therefore, suggests itself. Level or balance the diet according to the patient's requirements, and advise from two to three hours' vigorous exercise every day, and deep breathing in the open air.

All the causes as well as the cure of malnutrition were discussed under the subject of emaciation. (See "Emaciation," p. 477.)

Expenditure of vitality and failure to rebuild, primary causes