Emerging evidence suggests that chronic sleep restriction contributes to obesity. Targeting short sleep duration may therefore offer a novel and effective method of preventing and treating obesity. However, this area of research is only in its infancy, and a complete understanding of how chronic sleep restriction and obesity are linked is currently lacking. The aim of this paper is to briefly review epidemiological evidence for an association between chronic sleep restriction and obesity in adults, and outline the key methodological limitations of these studies. Particular attention is paid to the methods used to measure sleep and obesity, as well as the need to control for potential confounding variables. Methodological recommendations are provided for future studies that will facilitate a more complete understanding of how chronic sleep restriction and obesity are linked in the general population. This has implications for the development of public health programmes that target sleep as a modifiable risk factor for obesity.