If you love sleeping until noon over the weekends you might want to re-think your habits once you read this blog...
According
to a study published this month in the journal Current Biology, researchers from the Universities of Munich and Groningen
have shown that people with different sleep schedules on working days
and free days (what the
researchers called Social Jetlag) had triple the chances of being
overweight.
Social jetlag is "the discrepancy between what our body
clock wants us to do and what our social clock wants us to do," says Till
Roenneberg, a professor at the University of Munich's Institute of Medical
Psychology, in Germany. "It almost looks as if people on a Friday evening
fly from Paris to New York, and on Monday morning they fly back again.”
Roenneberg and colleagues have surveyed the sleep habits of
more than 65.000 European participants, comparing their sleep duration, sleep
timings and patterns over working days and free days. They have found out that
the Body Mass Index (BMI) of overweight people tended to be higher in those
with a bigger discrepancy of sleep between their biological and social clocks (sleep
discrepancy did not explain variations in body mass among those with a normal
BMI).
These results confirmed previous data that linked higher BMI
to sleep deprivation and irregular sleep schedules. Particularly, various
studies have found an increased risk of obesity, as well as chronic diseases
such as diabetes, among shift workers.
Some of the proposed explanations for the link between shift
work and obesity, such as irregular meal times and metabolism disruptions, may
help explain these social jetlag findings as well, Roenneberg says. "With
social jetlag, we're forced to eat at times when the body doesn't want to eat,
or isn't prepared for digesting food properly," he says. "All these
things coming together might influence the way you digest food and how you
incorporate it into your body fat. The result is that you become overweight or
obese."
This study also explained why “teenagers show the largest
discrepancy in sleep duration between free days and workdays”. Amongst other
obvious reasons (such as playing computer games until late or chatting on their
computers/mobiles :0)) this is because developmental changes in their circadian
clock are not matched by the school start timings, changes particularly evident
and fundamental at this phase.
So what can we do?
Adjusting our sleeping patterns isn’t easy. We just can’t
simply rely on our biological clocks to wake up, we have work schedules to keep
up to but paying more attention to our body clocks may be good start.
And here goes a link if you want to do a check-up to your sleep
Let's give this a thought, shall we?
