Dietary restrictions are a major component of Traditional Chinese Medicine (TCM) theory and practice. They mainly fall into three categories:
One category involves avoiding certain types of food for a specific illness.
For example: liver diseases should avoid spicy foods; heart diseases should avoid salty foods; edema should avoid salt, fried foods, and raw or cold foods; bone diseases should avoid sour and sweet foods; gallbladder diseases should avoid greasy foods; cold-related illnesses should avoid melons and fruits; sores and carbuncles should avoid fish and shrimp; patients with liver yang, liver wind, epilepsy, allergies, or convulsions should avoid "trigger foods"; and dizziness and insomnia should avoid pepper, chili, and tea.
Another category involves avoiding a specific type of food for a certain class of illnesses.
For example: patients with symptoms of yin deficiency and internal heat, phlegm-fire accumulation, or fluid damage should avoid warming and heating foods like ginger, pepper, and mutton; patients with lingering external pathogens, throat or eye diseases, sores, or after suffering from measles and smallpox should avoid "wind-agitating" foods like mustard, garlic, crab, and eggs; individuals with internal damp-heat should avoid "dampness- and heat-promoting" foods like malt sugar, pork, cheese, and rice wine; patients with spleen deficiency due to internal cold, serious illnesses, or postpartum recovery should avoid "cold-accumulating and damaging" foods like watermelon, plums, river snails, crab, and clams; and various cases of bleeding, hemorrhoids, and pregnant women should avoid "blood-moving" foods like taro and pepper. During pregnancy, substances that break blood, promote menstruation, are highly toxic, induce vomiting, or are acrid, hot, and slippery are prohibited.
The third category involves avoiding certain foods after taking medication.
For example: when taking diaphoretic (sweat-inducing) medicine, one should avoid vinegar and raw or cold foods; when taking tonics, one should avoid tea and radishes. Some of these dietary restriction theories have been proven to be reasonable, while others are not practical, but they can serve as a reference in the application of medicinal diets.
Medicinal diets are not to be consumed indiscriminately. Especially when eaten one after another without consideration, their pharmacological effects can cause problems if not aligned with one's actual constitution.