["Obesity paradox"-a phenomenon based upon the health-related outcome on quality of life].

The increase of body mass index (BMI) has already been recognized as one of the risk factors for many diseases. However, in patients with various diseases, data from large number of studies shows that when comparing with underweight and normal-weight patients, overweight and obesity have appeared better clinical prognosis, namely "obesity paradox". It has become one of the hot spots in domestic and foreign research areas of the sort. When studying the relationship between BMI and health-related quality of life (HRQoL), we discovered that when BMI was increasing among the elderly or people with chronic diseases, it could predict a better quality of life among these populations. The impairment of HRQoL in chronic disease was not caused by the impact of obesity but by chronic diseases. These evidence triggered the idea that whether higher HRQoL of obesity was the potential mechanisms that leading to a higher survival rate? It also provided a new entry point for searching possible mechanism in which related to the "obesity paradox" that raising new issues on reasonable weight management.