Eating less and not hungry may be related to indigestion, hypothyroidism, low physical exertion and other reasons. 1. Indigestion: Gastritis, gastrointestinal disorders and other digestive disorders can affect the digestive function, which can lead to delayed food emptying and the phenomenon of eating less but not hungry. 2. Hypothyroidism: the thyroid gland is unable to produce enough thyroid hormone or thyroid hormone resistance, which can lead to a decrease in metabolism and the phenomenon of eating less but not hungry. 3. Low physical exertion: If you seldom do physical labor or exercise, it can lead to a decline in energy consumption and the phenomenon of eating less but not hungry. It is recommended that people who eat less and are not hungry should go to the hospital in time if they have any other symptoms, so as to clarify the cause of the disease and carry out standardized treatment under the guidance of the doctor.