As the saying goes, "Don't take a bath when you are full, and don't run when you are hungry." This is based on science.

Wash your hair and take a bath immediately after meals, so that the whole body blood fills the subcutaneous capillaries too much, and the blood in the abdominal cavity is relatively reduced. In the long run, it will easily lead to indigestion and malnutrition, and hinder the normal physiological functions of related organs.