The reason why patients with acute pancreatitis lose weight is because of strict fasting, and after the opening of the diet, mainly to no oil semi-fluid diet or less oil semi-fluid diet, but also low protein diet, the intake of nutrients is relatively small, so the patient will have the symptoms of loss of weight, acute pancreatitis after the condition of the disease is cured after the gradual resumption of a normal diet, the body weight will also be gradually returned to normal. Chronic pancreatitis patients have to suffer from exocrine pancreatic insufficiency, that is, the pancreatic secretion of pancreatic lipase, pancreatic protease and other insufficiencies, resulting in the patient’s inability to digest the recurrent diarrhea, most of the fat diarrhea, will also cause the symptoms of wasting. There are many other causes of wasting, such as consumptive diseases, tuberculosis and malignant tumors, which need to be excluded.