The feeling of hunger often consists of two parts: one part is the feeling of fasting; the other part is the feeling of hunger in the mind. 1, the feeling of fasting, this feeling mainly occurs after the stomach empties the food in the stomach. Generally, after eating food, the stomach will be emptied after 2-5 hours, about 3 hours on average, after emptying, you will feel the feeling of empty stomach and want to eat. 2, hunger, the heart feels hungry, want to eat, this situation is often caused by the lowering of blood sugar. After the human body eats, food digestion, absorption into the blood, blood sugar rises, and the human body with activities, various aspects of energy application, blood sugar gradually reduced, to a certain extent will appear hunger.