Middle-aged and elderly people should pay attention to ensure nutrition, especially sugar, fat and protein are the three major nutritional elements of the human body. Protein and sugar are more beneficial to the liver. Rich protein can not only nourish the liver, but also prevent and reduce the fat infiltration and necrosis of liver cells, and promote the repair and regeneration of liver cells. Therefore, middle-aged and elderly people should eat some digestible high-protein foods, such as eggs, fish, lean meat, milk and bean products. Sugar can provide energy for liver cells, but too much sugar will be converted into fat and deposited in the liver, which is not good for the liver. Although fat is also the main source of human energy, if it is deposited too much in the liver, fatty liver will be formed, which will reduce the liver function and attract attention. In addition, eating more vegetables and fruits rich in vitamins and cellulose will help the liver maintain normal metabolic function and bile secretion and excretion, and keep the stool unobstructed, which is also an important measure to protect the liver's excretion function.