09 Aug Metabolic and endocrine responses to sleep loss
A host of research suggests that sleep loss impairs glucose metabolism, the process in which sugars from food intake is processed and stored or used to produce energy. Studies have consistently found short-term sleep loss decreases glucose tolerance and insulin sensitivity in healthy, young, lean adults.
In long-term (chronic) sleep loss, changes to glucose metabolism can increase the risk of obesity and type 2 diabetes. Combine this with the tendency when sleep-deprived to eat comforting foods, which are higher in fat and sugar, and it’s no wonder people who are sleep-deprived find it harder to lose weight than those who are well rested.
What’s more, both total and partial sleep deprivation have also been found to modify the normal daily rhythms of appetite-regulating hormones. Leptin, a hormone that suppresses appetite, and ghrelin, a stomach-derived peptide that stimulates appetite. When you do not get enough sleep, changes in these appetite-regulating hormones and an increase in food consumption can lead to weight gain and obesity.
These results have been found in a large population-based longitudinal study of sleep patterns known as the Wisconsin Sleep Cohort. In this study, participants reported their sleep habits through questionnaires and sleep diaries and provided a blood sample on one morning, prior to eating, to evaluate leptin and ghrelin levels. People sleeping less than eight hours a night (74.4% of the sample) had an increased body mass index (BMI).
Habitual short sleep was also associated with low leptin and high ghrelin. Since reduced leptin and elevated ghrelin are likely to increase appetite, this may explain the increased BMI observed and how insufficient sleep could contribute to developing obesity.