Dietotherapy is a subject that aims at prevention, health care and conditioning treatment, studies and sorts out the theory and experience of dietotherapy and food nutrition, and combines it with modern nutritional therapeutics.

Dietotherapy mainly studies the function and mechanism of different foods on diseases, and how to use the nutrients and cooking methods in foods to regulate the body, replenish deficiency, restore vitality, resist the invasion of diseases and promote the recovery of patients. Dietotherapy in a narrow sense is closely related to nutritional therapeutics, which includes not only reasonably inheriting the theories and experiences recorded in traditional medical works, but also collecting and sorting out the dietotherapy and nutritional experiences still circulating among the people, applying modern medical and nutritional knowledge to carry out scientific verification, and clarifying its exact curative effect and mechanism.

For example, by analyzing the nutritional components of food, it is found that the food for invigorating qi and blood is rich in nutrients such as protein, zinc, iron and vitamin B2. Foods that strengthen the spleen and regulate dampness have the characteristics of high potassium and low sodium, and are rich in zinc; The content of antioxidant nutrients in nourishing yin tonic is high. Generalized dietotherapy also includes food support, which means that healthy people use medicated diet to prevent diseases, or patients who are recovering use medicated diet to prevent disease recurrence and promote health recovery.