The best way to supplement protein in the elderly is through oral supplementation, but since the elderly have poor teeth and may have some underlying medical conditions and poor digestive function, protein can be supplemented by eating some soft, liquid food. Supplementation can be done intravenously if necessary. Elderly people can supplement protein by eating protein-rich foods such as milk, eggs, lean meat, beef, lamb, chicken, fish, and soy products. Since the elderly have bad teeth, and some underlying diseases, such as chronic gastritis, heart failure, portal hypertension, etc., can lead to indigestion in the elderly, the above food supplementation should be cooked into a fluid or semi-fluid form. For example, eggs can be made into egg custard, meat can be made into minced meat or chopped into meat froth and boiled in porridge, fish can be made into fish slips, and soybean products can be made into soymilk and tofu. In addition, for the elderly who cannot eat, protein can be supplemented by infusion of albumin. It is recommended to supplement protein under the guidance of a doctor to avoid delays.