Problems with the pituitary gland, thyroid gland and cancer can be reasons for a person's lack of appetite, Russian gastroenterologist and nutritionist Nuriya Dianova told URA.RU. "There are various diseases in which there may be problems with the pituitary gland. This is a gland that is located in the brain. Typically, (appetite) can be affected by pituitary gland tumors. There may be decreased thyroid function - hypothyroidism. It happens that there may be a decreased appetite with diabetes. Reduced appetite can occur with cancer, with people who undergo chemotherapy," explained the nutritionist. There are also diseases in which food lingers in the body, causing appetite not to come, the doctor added. "People who have chronic gastroduodenitis - inflammation of the duodenum and stomach, they have food slowly evacuated, the peristalsis of the stomach is disrupted and the food stays in the esophagus for a long time. This contributes to the fact that there is no appetite for the next meal," noted the gastroenterologist. In addition, appetite problems can occur when a person is under stress or has an infectious disease.