Symptoms such as not being able to eat or being full after two bites are considered loss of appetite, which means a decrease in appetite. Loss of appetite is mostly seen in gastrointestinal and hepatobiliary related diseases, and can be caused by chemotherapy drugs and neurogenic. Specific etiology: 1, excessive physical or mental labor, resulting in insufficient blood supply to the gastrointestinal tract stress, resulting in reduced digestive function; 2, uneven hunger and satiety, irregular diet, resulting in loss of appetite; 3, mental tension, social stress and anxiety, can lead to gastrointestinal dysfunction; 4, alcoholism, smoking and other unhealthy habits, can directly damage the gastric mucosa, reducing the secretion of gastric acid and other digestive juices, causing 5, consumption of cold food leads to stomach cold, nausea, vomiting, loss of appetite; 6, long-term medication affects the sense of taste, leading to loss of appetite; 7, diseases of the stomach, intestines, liver, gallbladder, pancreas and other diseases, causing loss of appetite; 8, the failure of other important organs, causing gastrointestinal dysfunction, can also cause loss of appetite.