It is very common for the elderly to suffer from hyperinflation of the lungs, and we should also pay attention to the dietary aspects when treating emphysema. The daily intake of protein is 1.2~1.5g/kg (body weight), with high-quality protein as the mainstay. Since dairy products tend to thicken the sputum which is not conducive to sputum discharge and can aggravate infection, they should be avoided, but dairy products are the main source of calcium and should be supplemented with calcium daily. Eat foods rich in vitamin A and C as well as calcium. Foods containing vitamin A such as pig liver, egg yolk, cod liver oil, carrots, pumpkin, apricots, etc.; have the effect of moistening the lungs and protecting the trachea; foods containing vitamin C have the function of anti-inflammatory, anti-cancer and anti-cold, such as dates, grapefruit, tomatoes, green peppers, etc.; foods containing calcium can enhance the antiallergic ability of the trachea, such as pork bones, green vegetables, tofu, sesame paste, etc. Daily intake of vitamin C 100 mg and vitamin A 5000 international units to enhance the defense ability of bronchial mucosa epithelium, maintain normal bronchial mucus secretion and cilia activity, improve the symptoms of respiratory tract infection and promote bronchial mucosa repair. Patients with hyperinflated lungs should avoid too cold, too hot, and raw foods in their daily diet, as they can stimulate the airways and cause paroxysmal coughing. Theophylline drugs are prone to gastrointestinal side effects, and care should be taken to avoid beverages such as coffee, tea and Coca-Cola.