Three new studies show that a short sleep duration, insomnia, and too much sleep all are reflective of a major problem in blood sugar metabolism that increases the risks for type 2 diabetes.

In the first study¹, healthy middle-age men and women went through two controlled 14-day periods of sedentary living and free access to food. During one study period they had 8.5 hours sleep. In the other they had 5.5 hours of sleep. During the short sleep time period changes in blood sugar tests showed they were heading in the direction of diabetes.

“Our findings raise the possibility that when the unhealthy aspects of the Westernized lifestyle are combined with reduced sleep duration, this might contribute to the increased risk of many overweight and sedentary individuals developing diabetes,” said Plamen Penev, MD, PhD, of the University of Chicago and a senior author of the study. “If confirmed by future larger studies, these results would indicate that a healthy lifestyle should include not only healthy eating habits and adequate amounts of physical activity, but also obtaining a sufficient amount of sleep.”

The next study² involved 1,741 men and women randomly selected and studied in a sleep laboratory. Those with insomnia or five or fewer hours of sleep per night had three times the risk of having type II diabetes. Those with insomnia who managed 5 – 6 hours of sleep per night had double the rate of diabetes.

The third study³ involved a group of 522 Finnish overweight patients with signs of impaired glucose tolerance. Some of these individuals went through an exercise and diet counseling intervention and others served as controls, and they were monitored over a seven year period. In the control group, too much sleep (nine hours or more) was associated with more than double the risk for having type Ii diabetes at the end of the study period.

In contrast, diet and exercise intervention was able to modulate the stress of too much sleep, to the point that the issue of too much sleep was not a problem (as long as other good things were being done).

The take home message is that leptin runs metabolism during sleep and your liver either burns fat and sugar in appropriate amounts or it does not. If your liver is clogged or getting mixed leptin messages due to leptin resistance, fat-burning during sleep will be inefficient and your liver will be unable to burn fat normally and make too much sugar. Simply not sleeping enough is a major stress to this system. And sleeping too much is reflective of a system not working right. The bottom line is that solving sleep problems will help improve blood sugar metabolism.

Many people report improved sleep simply following the Five Rules of the Leptin Diet.