Upper body fat lower body thin may be related to genetics, diet, lack of exercise, diseases (such as diabetes, Cushing’s syndrome) and so on. 1. Heredity: upper body fat lower body thin may be genetically related to the body type, and personal constitution, there is generally no good way to improve. 2. Diet: It may also be related to excessive intake of high salt, high fat and high sugar foods in the usual diet, especially the intake of trans-fatty acids, which results in a fat upper body and thin lower body. 3. Lack of exercise: If you usually sit down often to study or work, lack of exercise, but also easy to lead to excessive accumulation of subcutaneous fat, causing upper body obesity. 4. Diseases (1) diabetes: if there is diabetes, it is also easy to appear abdominal obesity, that is, the lower limbs of the legs are very slender, abdominal obesity, fat distribution is uneven. (2) Cushing’s syndrome: If the body’s cortisol secretion is too much, it may lead to abnormal fat distribution and metabolism, and there will also be centripetal obesity. It can be seen that there are many reasons why the upper body fat and lower body thin, if at the same time there are other uncomfortable symptoms, it is recommended to seek medical attention to identify the cause of the disease and then treatment.