Obesity is a person’s body excess calories can not reasonably consume, long-term accumulation in the body will form fat, once too many fat cells, affect the balance of body fat, beyond the normal proportion, will directly affect the human body shape and health. Therefore, it makes sense that obesity is defined as a disease. Excess calories in the body are usually the result of excessive amounts of food intake. When the intake is much larger than the consumption, it forms obesity, this kind of obesity caused by excess nutrition is called simple obesity, is also the reality of the obese people accounted for the largest type of obesity. There are some people because of certain diseases disrupt the metabolic and endocrine balance and cause obesity, this type is called pathological obesity, this part of the people is quite rare. In addition, there is also because of long-term use of a certain drug, so that the body side effects and obesity. Generally are hormone drugs cause patients endocrine flocculation, and finally cause obesity. In this case, some people will recover after stopping the use of drugs, but some people become stubbornly obese. There are many causes of obesity, and there are many hazards brought about by obesity. Whatever the purpose, I believe that every obese person is eager to lose weight successfully. Among the many methods of weight loss, weight loss surgery is an effective way to lose weight in the long run. The advantages of weight loss surgery are safety, high efficiency, low rebound rate after surgery and the ability to lose weight and treat related obesity complications at the same time.