Obesity is a growing global issue that increases the risk of individuals developing cardiovascular disease, nonalcoholic fatty liver disease (NAFLD), diabetes, obstructive sleep apnea (OSAS)，polycystic ovarian syndrome (PCOS), and many other disorders. Lifestyle change is the main treatment for obesity but has its limitations.

Bariatric surgery as an effective choice for reducing body weight and improving metabolic disorders has become increasingly popular. Bariatric surgery can significantly improve glucose-lipid metabolism. Dyslipidemia remission rates at 1, 3, and 5 years after surgery were 55%, 70%, and 95%, respectively. Additionally, changes in bone mineral density and improvement of PCOS and OSAS are observed after surgery. However, the mechanism underlying these improvements is not fully known. The individualized treatment of obesity needs to be supported by more research.

The aim of this Special Issue is to explore studies that may be helpful in guiding the diagnosis and treatment of obesity in the clinic. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Bariatric surgery
• Obesity and reproductive endocrinology
• Obesity and obstructive sleep apnea
• Obesity and the liver
• Obesity and depressive disorder