The nature and taste of the selected food should be determined according to the patient's physical condition after illness. People's physique is divided into cold, heat, deficiency and excess, and food also has its own attributes, that is, the so-called "four qi", which means that food will have the functions of "cold, heat, warmth and coolness" after entering the human body. If it is between the four, neither too warm nor too cold, then it is "flat". Only when patients choose the corresponding food according to their own physique can they help their body recover. For example, people who have a high fever for a long time, because they consume body fluids and damage yin qi after illness, are mostly deficient heat. Diet should choose cold foods such as watermelon, pear, tomato, water chestnut, wax gourd, cucumber, sugarcane juice, mung bean, American ginseng, turtle and old duck. After a long illness, if you feel cold and weak in yang, you should choose litchi, longan, chestnut, red dates, beef, dog meat, milk and ginger as isothermal foods.
In addition, for diabetic patients, after blood sugar control, avoid eating foods with high sugar content, so as not to induce blood sugar to rise again. People with allergies, such as patients with bronchial asthma, should not eat fish, shrimp, seafood, fresh milk and other foods after illness to prevent the recurrence of old diseases caused by eating allergies. Clinical common food recurrence cases include infectious lung diseases, hepatitis, gastritis, gallbladder diseases, nephritis, diabetes, intestinal infectious diseases and so on. Especially for the elderly with these diseases, if they don't pay attention to their diet during the recovery period, it is easy to have food recurrence.