A large Japanese study suggests eating habits are only part of the reason why short sleep duration is interconnected with obesity. Findings published in the May issue of SLEEP show short sleep and high Body Mass Index are linked to a tendency to eat out and a taste for fatty foods. The authors suggest other unknown biologic factors are also at play.
Researchers reached this conclusion using a statistical analysis based on the results of a questionnaire about lifestyle combined with data from annual health checkups. About 3,800 white collar male employees at a Japanese energy company, ages 40 to 59, participated in the study.
The survey contained mostly “yes or no” questions about sleep length, dietary patterns, health history, exercise and substance use.
People categorized as short sleepers (6 hours or less) tended to weigh more and exercise less. The same group was also more likely to prefer fatty food, frequently snack and eat out more. Those dietary habits were also associated with high BMI, a characteristic of obesity.
Based on previous research, the authors state other physiological functions may also drive the relationship between sleep duration and obesity. Other studies have linked sleep restriction to levels of the appetite-regulating hormones leptin and ghrelin.
The study does have some shortcomings as noted by the authors. Women did not participate due to privacy concerns. The findings may not apply to everyone because the study only included middle-aged Japanese men. The measure for sleep duration was self-reported by participants and may not be true in all cases.
Read more about sleep and obesity and sleep and weight gain.