Think it might be in your genes to be overweight? A new study suggests getting more sleep could help you overcome those genes and lose unwanted pounds.
The study says those who get lots of sleep -- meaning around nine hours a night -- are less likely to put on weight, even if they have the genes that predispose them to weight gain.
A number of studies have shown there's a connection between sleep and weight. Some studies have found that people who sleep less than five hours a night have an increased risk of developing Type 2 diabetes. Other studies have found that people who are night owls tend to eat more -- and eat worse.
But this study, published Tuesday in the journal Sleep, is one of the first to look at what role genetics plays. It was able to do that by studying twins, who share similar genetics but whose environment and lifestyles might be quite different.
The researchers from the University of Washington Medicine Sleep Center studied 1,088 pairs of twins: 604 were identical twins -- who share the same genes -- and 484 were fraternal twins, who share some but not all the same genes. All were part of the university's Twin Registry and the average age of the participants was 37.
As expected, the participants who reported they slept the least had an increased risk for having an elevated BMI (body mass index). Among the participants who were getting less than seven hours of sleep per night, their genes seemed to play more than twice as large a role in determining their BMI than those who were getting nine or more hours of sleep each night.
"The results suggest that shorter sleep provides a more permissive environment for the expression of obesity related genes," study leader Dr. Nathaniel Watson said in a statement.
"Or it may be that extended sleep is protective by suppressing expression of obesity genes."
It's not known exactly which genes affect our weight, but some research has suggested the genes that govern glucose metabolism play a role, as do genes affecting energy use, fatty acid storage and "satiety" -- meaning how hungry we feel after eating.
Most of the twins who participated in the study were Caucasian and in their 30s, raising questions about whether the findings would apply to other races and age groups.
Previous research has also shown that sleep deprivation can play havoc with our hunger hormones, decreasing the levels of those hormones that make us feel full.
While it's unlikely that we can sleep our way to weight loss, getting more sleep might allow us to control our eating and to do more exercise -- two things that we know do lead to a healthy weight.
