Losing Sleep and Gaining Weight

Inadequate sleep causes a variety of changes in the hormone levels of the body. These changes may lead to weight gain and an increased risk for diabetes.

Cortisol is a hormone that helps the body deal with stress. Cortisol also regulates glucose levels and how well our body responds to insulin. Your cortisol level is highest at around 8 am. Cortisol then declines throughout the day reaching its lowest level around midnight. In persons that do not get enough sleep (less than 7 hours each night) the rate of decline in the cortisol level is six times slower.

The slower rate of decrease means that the cortisol levels are higher throughout the day. Higher cortisol levels increase appetite and blood glucose levels. These changes result in weight gain. Higher cortisol levels cause insulin resistance.

Insulin resistance interferes with insulin action so the glucose levels in the blood rise which contributes to the development of diabetes.

Leptin is a hormone that controls your appetite. Leptin increases when you eat causing you to feel full. You feel hungry when your leptin levels decrease. Low leptin levels signal the body’s need for energy by making you feel hungry.

Inadequate sleep causes a 2 0percent decrease in leptin levels resulting in increased appetite. The increase in appetite and calorie intake is greater than what is needed for the extra time that you are awake. The excess calorie intake results in weight gain.

We saw that Leptin acts like a brake on your appetite — signaling you to stop eating. By contrast, ghrelin is the “gas pedal” for your appetite – it stimulates your appetite. Inadequate sleep causes ghrelin levels to rise by up to 30 percent causing a significant increase in appetite.

Ghrelin especially increases your appetite for high carbohydrate foods. Increased calorie intake causes weight gain. Increase carbohydrate intake directly contributes to higher blood glucose levels and the risk of diabetes.

Current evidence suggests a possible role for chronic sleep loss in the current epidemic of obesity.

Rates of obesity in the United States have gone up in direct proportion to the decrease in the average number of hours people sleep. Studies have also demonstrated that people that sleep less, weigh more. Weight loss efforts are hindered by inadequate sleep. Losing weight requires you to eat fewer calories.

Attempts to restrict calories may be adversely affected by the increased appetite that results from too little sleep. Too little sleep increases appetite by increasing ghrelin (which stimulates appetite) and decreasing leptin (that signals fullness).

Persons that do not have adequate sleep have higher glucose levels. Glucose levels after breakfast in sleep deprived persons are 15 mg/dl higher. This increase is clinically significant and represents a significant decrease in how the body manages blood glucose.

Research studies have shown that inadequate sleep reduces the production of insulin by up to 30 percent which also contributes to slower removal of glucose from the blood.

There is good news. All of these changes are reversible by getting adequate sleep – seven or more hours each night.