The relationship between sleep and obesity

Vanessa DeClercq and Cindy Forbes

Strategies for preventing and treating obesity are complex and far greater than simply eating less and moving more. While multiple factors contribute to the growing obesity epidemic, studies have shown an important association between habitual sleep duration and obesity. Possible mechanisms linking sleep and obesity include changes at the physiological level (hormonal metabolic changes) that may alter hunger and appetite as well as factors that reduce energy expenditure such as reduced thermogenesis, fatigue and decreased physical activity.
Reports suggest that the relationship between body mass index (BMI) and sleep is U-shaped rather than linear. Although BMI is the most reported measure of obesity, there are other indicators of adiposity such as fat mass, waist circumference or waist-to-hip ratio.

Recent studies have examined sleep patterns and other adiposity measures such as body composition. For example, Poggiogalle et al. reported a negative association between fat mass and sleep duration and Ford et al. have documented an inverse association with waist circumference. However, the results for BMI are inconsistent, some showing no association and some reporting negative or U-shaped associations. These mixed findings highlight the need for additional study of body composition as it relates to sleep duration. Accordingly, the aim of this study was to examine the association between sleep duration and obesity using multiple measures/indicators of obesity in the Atlantic PATH cohort.