The results of many epidemiological studies show that overweight/obesity increases the incidence and mortality of some tumors, such as breast cancer, endometrial cancer, esophageal cancer, pancreatic cancer, colorectal cancer, gallbladder cancer, pancreatic cancer, hepatocellular carcinoma, renal cell carcinoma and bladder cancer. The traditional theory is that adipose tissue is an endocrine metabolism active organ acting through endocrine, autocrine and paracrine pathways, and the occurrence and development of tumors may be related to the synthesis and bioavailability of sex hormones and steroid hormones, as well as the release of insulin, insulin-like growth factor, leptin, growth hormone, and inflammatory cytokines, and the abnormal energy expenditure, especially insulin-like growth factor, which can destroy cells. Alterations in growth factors can disrupt the normal balance between cell proliferation, differentiation and apoptosis. In order to reduce the incidence of obesity-related tumors, it is necessary to strengthen the treatment and prevention of obesity, mainly through changing the dietary and exercise habits of obese patients, especially need to be alert to abdominal obesity. Obesity in preschool, school-age and adolescent children often continues into adulthood, causing adult obesity. Therefore, for overweight or obese children and adults, should follow a reasonable diet, adhere to the healthy lifestyle of exercise, reasonable weight loss. For long-term super obese patients, metabolic weight loss surgery can be considered. Metabolic Weight Loss Surgery “Gastric Bypass” Gastric bypass surgery refers to a series of similar surgical procedures used in the treatment of obesity, with the following common features: the surgery firstly divides the stomach into upper and lower portions, the smaller upper portion and the larger lower portion, and then truncates the small intestine, rearranging the position of the small intestine to change the pathway of the food through the digestive tract, slowing down the rate of gastric emptying and shortening the small intestine. gastric emptying, shortening the small intestine, and reducing absorption. By 2005 surgeons had developed several different alignment options, forming several branches of gastric bypass surgery. According to 2008 data from the National Center for Health, gastric bypass surgery has replaced gastric reduction surgery as the most popular weight loss surgery in the United States since 2000, with about 100,000 cases performed annually. In 2004, the National Institutes of Health announced the latest evaluation of gastric bypass surgery: the most effective medical treatment for morbid obesity is bariatric surgery. Results: Loss of 65%-80% of the overweight portion of the body weight. Relief of hypertension in 70% of patients. Significant improvement in obstructive sleep apnea. 90% of patients with type II diabetes return to normal blood glucose when medication is discontinued. Improvement in venous thromboembolic disease. Low back pain and joint pain relief improved.