Insomnia and obesity.

PURPOSE OF REVIEW: Accumulating data suggest that short sleep plays a role in the development of obesity in general population. Insomnia disorder is characterized by short sleep and may persist for years. The question whether these patients have a higher risk of obesity is of socioeconomic as well as therapeutic interest.

RECENT FINDINGS: Numerous recently published cross-sectional and longitudinal studies show positive as well as negative associations between short sleep and overweight. Critical reviews note several methodological limitations that weaken the assumption of short sleep duration as the potential cause for obesity. From a sleep medical perspective, a basic methodological problem is the lack of a biological cut-off for short sleep duration. Therefore, recent findings on the relation between emotional stress in short sleepers and incident of obesity opens a more promising perspective on sleep quality as a possible factor. A few studies on patients with insomnia disorder, however, do not show higher BMIs adding data to a research puzzle.

SUMMARY: The relation of sleep duration and incident obesity so far has insufficient evidence base. Few data on patients with insomnia disorder do not confirm the association. Further research is necessary with focus on sleep quality instead of sleep duration.