In the broadest sense all food is stimulating to the functional activities of the body; but when the digestive and assimilative powers are lowered, less variety and less quantity of food can be tolerated, and foods that in health are never needed may become necessities; such foods, for example, are cod-liver oil and the various preparations of meat, such as albumoses or peptones, meat juice, etc.

Certain food substances have a distinctly stimulating action at all times. The various condiments possess a local action of this kind upon the alimentary organs, but not a general or systemic action. The latter stimulation, manifested especially upon the nervemuscular apparatus, is derived from such substances as strong beef extracts, coffee, tea, and alcohol, all of which at times are of great service in the dietetic treatment of disease. The effect of sugar as a stimulant to relieve muscular fatigue has been described in the previous section.