Always feel hungry to consider the following types of factors: 1, gastrointestinal function is relatively poor, food into the digestive tract without the normal gastrointestinal mucosa digestion, absorption, through the digestive tract excretion or participate in other material metabolic pathways, the body also needs glycogen, lipids and protein and other nutrients to provide energy to maintain basic organ functions, there will be frequent hunger; 2, mental factors, emotional hyperactivity or Other psychological factors, easy to stimulate the central nervous system to control appetite nerve tissue, nerve tissue continued excitement, lowering the threshold of sensation, will also appear always hungry; 3, hyperthyroidism or thyroid hormone exceeds the physiological normal value, the body’s basal metabolic rate is significantly higher, the gastrointestinal tract peristalsis is too fast, the normal amount of food can not meet the body’s metabolism, will soon appear hunger.