Cirrhosis develops from various chronic liver diseases and is a common end-stage chronic liver disease. At present, through active etiologic treatment (e.g., antiviral, alcohol cessation) and anti-hepatic fibrosis treatment, the condition of most patients can be controlled, and some of them have their condition reversed and the degree of hepatic fibrosis reduced. In order to further improve the clinical efficacy, the medical profession has begun to pay attention to the nutritional problems of patients with cirrhosis, because patients with cirrhosis are often malnourished and it is very important to the prognosis of the patients. Why are cirrhotic patients malnourished? This is related to the site and characteristics of the disease. The liver is the largest metabolic organ in the body, where many nutrients are synthesized and metabolized, such as proteins, sugars and fats as well as many vitamins. Malnutrition occurs when the liver becomes diseased and its ability to synthesize and metabolize nutrients is diminished. In addition, insufficient dietary intake due to early satiety caused by large amounts of ascites, bloating after eating and decreased appetite due to low-salt and low-protein diets, digestive and absorptive disorders due to abnormal secretion of bile and pancreatic fluid and overgrowth of intestinal bacteria, as well as disorders of nutrient metabolism and decreased function of the liver in storing nutrients, can lead to or exacerbate malnutrition. The above reasons are superimposed together, so that we often see very thin advanced cirrhosis patients. In the early stage of cirrhosis, the so-called compensated cirrhosis, although patients do not show obvious wasting, they may also be at risk of malnutrition due to short-term reduction in food intake or weight loss. Some experts believe that malnutrition should be listed as an important complication of cirrhosis like ruptured esophagogastric fundal vein bleeding, ascites and hepatic encephalopathy. Overseas studies have found that 30% of patients with compensated cirrhosis are at risk of malnutrition, while the prevalence of malnutrition in patients with decompensated cirrhosis is as high as 60-80%. We have recently conducted a survey on cirrhotic patients and nutritional status. After analyzing the clinical data of 150 patients that had been collected, 48 patients were found to be malnourished and 13 of them had a body mass index of less than 18, which puts them in the category of wasting. Among these malnourished cirrhotic patients, three have died and three have developed hepatocellular carcinoma. Malnutrition can reduce the patient’s body function, endocrine disorders, decreased immune resistance to disease, etc. It increases the risk of complications such as esophagogastric fundus vein rupture and bleeding, hepatic encephalopathy, ascites, and hepatorenal syndrome in patients with cirrhosis, and affects the survival rate and mortality rate after liver transplantation, and it is an independent predictor of patient’s survival rate. Therefore, it is important to emphasize the nutritional problems of patients with liver cirrhosis, to assess the nutritional status of patients in time, to detect malnutrition and to provide nutritional support, which is important for the prognosis of the disease. However, patients with cirrhosis and clinicians do not pay enough attention to nutritional problems, and only begin to pay attention when patients are wasting away. Malnutrition in patients with cirrhosis manifests itself in many ways. If protein-rich meat and vegetables are not eaten enough, the levels of prealbumin and albumin in the liver function indexes will decrease. Chronic insufficiency of albumin can cause failure and aggravation of cirrhosis in various systems, organs and tissues of the body. In recent years, vitamin D deficiency has been found to be a common problem in chronic liver diseases, with a prevalence as high as 64%-92%, and is closely related to the severity of the disease. For example, vitamin D deficiency is associated with sustained virologic response and degree of liver fibrosis in patients with hepatitis C. Vitamin D deficiency is also present in patients with steatohepatitis, while vitamin D deficiency is most common in patients with primary biliary cirrhosis. The vast majority of the 150 cirrhotic patients we evaluated had vitamin D levels well below normal. Vitamin D deficiency in cirrhotic patients can lead to the development of associated bone disease, and in the later stages of the disease patients may develop osteoporosis, bone pain or even fractures. In addition, deficiencies of vitamins A, B, folic acid and some trace elements are not uncommon in patients with cirrhosis. In fact, the wasting of cirrhotic patients is not all malnutrition, patients such as the combination of diabetes, tuberculosis, thyroid disease and even advanced tumors, can be wasting. The decrease in serum albumin content may also be due to the large loss of urinary protein in associated nephropathy. Therefore, careful clinical differentiation is required. Since malnutrition in cirrhotic patients is not easy to diagnose in the early stages of the disease and can be easily missed in the later stages due to the presence of ascites, self-monitoring, early detection and timely correction of malnutrition are particularly important. What patients can do on their own is to record the change in weight and calculate the body mass index (BMI) by using a formula: BMI = weight (kilograms)/height (meters)2, if the BMI is less than 18 it suggests that there is a risk of malnutrition, this is one of the easiest assessment methods, suitable for patients to carry out self-monitoring, and to detect nutritional changes at any time. Of course, only rely on BMI to assess the nutritional status is not enough, nutritional evaluation, in addition to including nutritional risk screening, should also include some anthropometric content, such as the upper arm circumference, triceps skin fold thickness, and handgrip strength and the results of some biochemical tests, through which the doctor to carry out a comprehensive nutritional assessment by the dietitian to calculate the daily nutritional requirements of the energy, to achieve individualized treatment. Patients should also pay attention to weight changes and eating changes in a timely manner, and adhere to dietary supplements as long as they can eat. However, the daily diet of cirrhotic patients is often not sufficient to maintain metabolic needs, and dietary intake and supplementation should be increased appropriately to achieve nutritional balance as much as possible. Patients without hepatic encephalopathy should consume adequate amounts of protein. In order to prevent the occurrence of diarrhea or bloating, appropriate probiotics and soluble dietary fiber should be taken to improve the absorption of nutrients in the intestines by improving intestinal nutrition and balancing intestinal flora. The fasting period from bedtime to early morning in cirrhotic patients is equivalent to three days of starvation in normal people, so the European Society for Enteral Parenteral Nutrition suggests that poorly nourished cirrhotic patients should have additional meals before bedtime, and patients with abnormal glucose metabolism can adjust the type and number of meals before bedtime according to the fasting blood glucose level in early morning, and the long-term adherence will improve the nutritional status. For patients with vitamin D deficiency, vitamin D supplementation is recommended to reduce the incidence of hepatic bone disease. Other deficient nutrients should be supplemented accordingly. In summary, it can be seen that nutritional therapy is an important part of the comprehensive treatment of liver cirrhosis and is an issue to which clinicians are paying more and more attention. For outpatients with milder disease, it is important to do self-monitoring, correct abnormal weight in time, detect the risk of malnutrition or existing malnutrition as early as possible, and at the same time formulate a nutritional supplementation program suitable for themselves with the help of their doctors, so as to maximize the benefit from it.