When it comes to priorities, sleep for many is way down the list. If you would rather dance than doze, be warned! A few nights of sleep deprivation may not just leave you feeling tired and ill-tempered; it could be seriously damaging your health.
Insulin sensitivity or insulin resistance, a major forerunner to Type 2 diabetes occurs when the body's ability to use insulin is impaired. Insulin is the hormone used to regulate blood sugar levels. When the body is unable to use insulin properly, blood sugar levels rise to dangerously unhealthy heights. Poor diet and exercise regimes will lead to insulin sensitivity, but lack of sleep is a major contributor, with one study showing that after only four nights of sleep deprivation, the insulin sensitivity of participants was reduced by 16%. More alarmingly, the insulin sensitivity of fat cells was reduced by 30%, to similar levels of people identified with diabetes and obesity.
Lack of sleep also triggers a response in two other hormones responsible for appetite control, leptin and ghrelin. Leptin levels fall, triggering increases in appetite and food cravings, while ghrelin levels increase, stimulating hunger and triggering cravings for sweet starchy food. With the brain groggy from lack of sleep and unable to provide the correct insulin response, it craves carbohydrates for energy to carry on. The body will recover relatively quickly to short term lack of sleep, but ongoing sleep deprivation, associated insulin sensitivity and repeatedly acting on these sweet cravings, leads to weight gain and its associated detrimental health effects.
Fortunately, the effect of insulin sensitivity can be reversed with recovery sleep. Simply shifting your bedtime forward as little as half an hour and attempting to achieve a regular 6-8 hours good quality sleep each night will dramatically improve your long term health outcome.