Dietary therapy uses food to treat and prevent disease. Chinese medicine philosophy believes that a human and his/her environment form an organic whole. Humans are integral parts of the environment. The environment provides air, water, and food. Therefore, the environment can also keep the person healthy.

Chinese medicine philosophy has an element theory to classify food into five categories. Food in the same category have common features, whereas those in different categories have different tastes, flavors, and functions. Food in different categories correspond to different internal organs. For example, salty foods for the kidney, bitter foods for the heart, sweet foods for the spleen, acrid foods for the lung, and sour foods for the liver. Moreover, dietary therapy uses the law of opposites; cold foods treat hot diseases and hot foods treat cold diseases. Foods with lifting properties can be used to treat depressed and hypofunctional conditions. Foods with sedating properties can be used to treat overactive and hyperfunctional conditions.