Lung cancer tumor itself or mediastinal lymph node metastasis can compress the esophagus, resulting in mechanical obstruction of the esophagus and causing difficulty in eating. Patients with advanced lung cancer tend to consume more, and if they have severe hypoproteinemia, they can develop fluid in the chest and abdominal cavity and intestinal edema, which can lead to gastrointestinal dysfunction and affect patients’ feeding. When liver metastasis is serious, it can lead to serious damage of liver function, resulting in abnormal metabolism of bile and other digestive juices, which can also lead to loss of appetite and affect the patient’s feeding.