People that sleep a lot are fat and lazy, right? Nope: toss that old idea out right now, because a new study suggests that sleeping for less than seven hours promotes genetic influences associated with weight gain.
We've known for a while that there are genetic influences that can contribute to obesity; things like glucose metabolism, energy use, fatty acid storage and satiety. But a study carried out at the University of Washington tried to get to the bottom of how sleep might affect those genetic traits and their impact on BMI.
To do that, the researchers studied 1088 pairs of twins, analysing their sleeping patterns and genetic markers. The results, published in Sleep, show that those who sleep for less than seven hours are twice as likely to experience the genetic effects that influence weight gain compared to those who sleep for more than nine hours.
Not just that, but the genetic differences have a real measurable, effect. Those who slept for less than seven hours had higher BMIs on average, and the researchers attributed 70 per cent of the differences to the genetic effects. Speaking to EurekAlert, Nathaniel Watson, one of the researchers, explained:
"The results suggest that shorter sleep provides a more permissive environment for the expression of obesity related gene. Or it may be that extended sleep is protective by suppressing expression of obesity genes."
What all this suggests, of course, is that conventional weight loss measures ought be combined with extra sleep to be truly effective. And that is a great excuse for sleeping in. [Sleep via EurekAlert]
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