Studies Probe Whether Sleep Deprivation Can Affect Your Weight

— -- We are a sleep-deprived nation and those suffering the most are the 15 million Americans who work late night and early morning shift work. Working these hours can be so detrimental that the World Health Organization has classified shift work as a “probable” cause of cancer.

Frank Scheer of Brigham and Women’s Hospital and Harvard Medical School is a neuroscientist who studies sleep and circadian disorders.

“Lack of sleep can lead to an increased risk for cardiovascular disease or heart and blood vessel disease, to increased risk of diabetes and also weight gain,” Scheer said.

And Scheer says it’s not just a result of overeating. He says when you’re sleep-deprived, your body is stressed.

In a recent study testing the effect of sleep on weight loss, all participants restricted their calories, but those that slept under five hours a night saw their body consume lean muscle mass instead of fat. Those dieters that slept a full eight hours burned twice as much fat as those who slept less.

Previously, the effect of sleep deprivation on weight gain was thought to be primarily tied to the over production of hormones that make you feel hungry and stimulate the appetite, but this new physiological difference in the way the body actually fuels itself during times of sleep deprivation points to an even more complicated set of issues.

As Scheer explained: “In shift workers, when they eat calories, many of their calories during the nighttime -- the body is not as well able to cope with the food and not to process it in the right way.”

Scheer points to a study done in the Netherlands where sleep was restricted to four hours in one group while the other group was allowed a full night’s sleep. The researchers found the sleep-restricted group had a 21-percent decrease in their insulin efficiency after one night of sleep deprivation.

Scheer points to the negative long-term effect that could have on the body -- specifically the increased risk of diabetes.

“It’s unnatural for your body to be functioning, to be up and awake and eating during the nighttime,” he said.

And while the studies linking shift work and sleep deprivation to weight gain have not been done on a longitudinal basis, the links to metabolic challenges for those on the overnight shift are becoming clearer.

While Scheer recommends shift workers eat meals during regular daytime hours, for many working long shifts overnight that may not be easy. Ultimately the reality for those working the graveyard shift: exhaustion and stressing the metabolism may be all in a night’s work.