Human fat cells have a fixed distribution. Except for some hormonal or pathological abnormalities, the male abdomen is the first attack. For women, hips and thighs are the central areas of the first episode. If you are fat, the hips, thighs and abdomen are tied as the central area in the first episode, and the fat abdomen is the central area in the first episode. If the band is tied too tightly for too long, it will compress the superficial circumflex branch of the external iliac artery and the uppermost branch of the anterior trunk of the internal iliac artery. These two arteries supply abdominal adipose tissue and a part of external oblique muscle and internal oblique muscle from below, while the upper part of abdominal fat and another part of external oblique muscle and internal oblique muscle are supplied by other arteries and small vessels. Only fat is considered here, and muscle is ignored first. Compression of these two arteries will lead to long-term ischemia of some abdominal adipocytes, and type 2 mast cells (1 mast cells are related to allergic reaction) will release exogenous lipophilic growth factor (EPFGF) and vascular endothelial growth factor (VEGF), thus promoting compensatory proliferation of adipocytes and promoting the formation of new blood vessels and collateral circulation. Because of the compensatory proliferation of adipocytes, the abdominal circumference is enlarged. In men, due to the obvious advantage of abdominal fat, EPFGF is inhibited by negative feedback regulation in the abdomen, and more EPFGF has little effect, so this change is not obvious. In women, due to the high proportion of adipose tissue in buttocks and thighs, EPFGF is not completely inhibited in the abdomen, so it is more reactive and easier to increase the abdominal circumference. As for the waistline, it doesn't matter much. But there will be a few exceptions. As mentioned above, VEGF promotes new blood vessels and collateral circulation. If it forms quickly, it can restore blood supply, and the abdominal circumference does not increase obviously, but the new fat cells will not disappear ... A few people do not have a good collateral circulation, and new blood vessels grow from below, which may lead to blood vessels in the waist. This compressive ischemia leads to the occurrence of EPFGF under long-term compression. It is generally believed that there will be statistical differences when the daily compression time is 14 hours.