Obesity is a common and ancient group of metabolic disorders. When the body eats more calories than it consumes, the excess calories are stored in the body in the form of fat, and the amount exceeds the normal physiological needs and reaches a certain value, then it evolves into obesity. Normal male adult adipose tissue weight accounts for about 15% to 18% of body weight, women account for about 20% to 25%. With the growth of age, the proportion of body fat increases accordingly. Due to the increase of body fat, the weight exceeds 20% of the standard weight or the body mass index [BMI = weight (Kg) / (height) 2 (m2)] is greater than 24 is called obesity. If there is no obvious cause can be found is called simple obesity; with a clear cause is called secondary obesity. The external causes are mainly too much diet and too little activity. Caloric intake more than caloric consumption, so that fat synthesis increase is the material basis of obesity. Internal because the human body intrinsic factors make fat metabolism disorder and cause obesity. Specific as follows: 1, genetic factors human simple obesity onset has a certain genetic background. mayer and other reports, one of the two parents is obese, its children obesity rate is about 50%; both parents are obese, its children obesity rate rose to 80%. Human obesity is generally considered to be polygenic heredity, heredity in its onset plays a susceptible role, the formation of obesity still with the way of life behavior, feeding behavior, hobby, insulin response and the interaction of psychosocial factors. 2, neuropsychological factors It is known that there are two pairs of neural nuclei related to feeding behavior in the hypothalamus of human and many animals. One pair is the ventral contralateral nucleus (VMH), also known as the satiety center; the other pair is the lateral ventral nucleus (LHA), also known as the hunger center. When the satiety center is excited, there is a feeling of satiety and refusal to eat, but when it is destroyed, there is a great increase in appetite; when the hunger center is excited, there is a strong appetite, but when it is destroyed, there is anorexia and refusal to eat. Both of them regulate each other and restrain each other, and are in dynamic equilibrium under physiological conditions, so that appetite is regulated in the normal range and normal weight is maintained. When hypothalamic lesions occur, regardless of the sequelae of inflammation (such as meningitis, encephalitis), trauma, tumors and other pathological changes, such as the destruction of the medial ventral nucleus, the lateral ventral nucleus is relatively hyperfunctional and anorexia, causing obesity. Conversely, when the ventral lateral nucleus is destroyed, the ventral medial nucleus is relatively hyperfunctional and anorexic, causing emaciation. 3, hyperinsulinemia In recent years, the role of hyperinsulinemia in the development of obesity is notable. Obesity often coexists with hyperinsulinemia, but it is generally believed that hyperinsulinemia causes obesity. High insulinemic obese person’s insulin release amount is about 3 times of normal people. 4, brown adipose tissue abnormal brown adipose tissue is a kind of adipose tissue discovered in recent years, and mainly distributed in the subcutaneous and internal organs around the white adipose tissue corresponding. The distribution of brown adipose tissue is limited, only in the interscapular region, the back of the neck, the axilla, the mediastinum and around the kidney, and its tissue appearance is light brown, with relatively small changes in cell volume. White adipose tissue is a form of energy storage in which the body stores excess energy in the form of neutral fat, which is hydrolyzed and used by the body when it needs energy. The volume of white adipocytes varies greatly with energy release and energy storage. The brown adipose tissue is functionally a thermogenic organ, i.e., when the body ingests or is stimulated by cold, the fat in the brown adipocytes is burned, thus determining the level of energy metabolism of the body. These two conditions are called feeding-induced thermogenesis and cold-induced thermogenesis, respectively. Of course, the function of this particular protein is influenced by a variety of factors. Thus, the brown adipose tissue, a thermogenic tissue, is directly involved in the total regulation of heat in the body, distributing excess heat from the body to the outside, and bringing the body’s energy metabolism into balance. 5.Other Excessive eating can produce excessive intestinal gastric inhibitory peptide (GIP) through stimulation of the small intestine, and GIP stimulates insulin release from pancreatic beta cells. In the pituitary function is low, especially growth hormone reduction, gonadotropic and thyroid hormone reduction caused by gonadal, thyroid function can occur special type of obesity, may be related to fat mobilization reduction, synthesis relative increase. Clinical obesity is more frequent in women, especially in menstruating women or menopausal women or those taking oral contraceptives, suggesting that estrogen is related to fat anabolism. When the adrenal cortex is hyperactive, the secretion of cortisol increases, promoting glycogen xenobiogenesis, increasing blood sugar and stimulating insulin secretion, so fat synthesis increases, while cortisol promotes fat decomposition.