Abstract
The prevalence of obesity continues to increase worldwide. Multiple risk factors and complex mechanisms are involved in the development and maintenance of obesity. Recently, emerging evidence has indicated that the circadian rhythm is important for regulating metabolism because the circadian system modulates energy metabolism and enhances certain energetic activities during day and night. Lifestyle also has a great impact on the circadian system. In addition to traditional risk factors, sleep and circadian disruptions are known modifiable risk factors for obesity and other metabolic disorders. This paper reviews recent evidence of relationships between energy metabolism and the circadian system and discusses how sleep disruption and circadian misalignment influence the development of obesity.