Science Now wrote:
The study concerns a phenomenon called "social jetlag." That's the extent to which our natural sleep patterns are out of synch with our school or work schedules. Take the weekends: many of us wake up hours later than we do during the week, only to resume our early schedules come Monday morning. It's enough to make your body feel like it's spending the weekend in one time zone and the week in another.
But is social jetlag actually bad for your health? To investigate, chronobiologist Till Roenneberg at the University of Munich in Germany and colleagues compiled data from tens of thousands of responses to an internet survey on sleep patterns and other behaviors. Previous work with such data has already yielded some clues. "We have shown that if you live against your body clock, you're more likely to smoke, to drink alcohol, and drink far more coffee," says Roenneberg.
... While previous studies have shown a link between sleep duration and obesity, the new work highlights the importance of sleep timing, says Kristen Knutson, a sleep researcher at the University of Chicago in Illinois. "We've known for a while that shift workers are associated with increased health risks, and shift workers have extreme variability in their sleep timing between workdays and non-workdays," Knutson says. "This paper suggests it's not just the extreme cases of irregular bed times, but even a more modest difference between weekends and weekdays of an hour or two seems to be associated with health outcomes like obesity."
But is social jetlag actually bad for your health? To investigate, chronobiologist Till Roenneberg at the University of Munich in Germany and colleagues compiled data from tens of thousands of responses to an internet survey on sleep patterns and other behaviors. Previous work with such data has already yielded some clues. "We have shown that if you live against your body clock, you're more likely to smoke, to drink alcohol, and drink far more coffee," says Roenneberg.
... While previous studies have shown a link between sleep duration and obesity, the new work highlights the importance of sleep timing, says Kristen Knutson, a sleep researcher at the University of Chicago in Illinois. "We've known for a while that shift workers are associated with increased health risks, and shift workers have extreme variability in their sleep timing between workdays and non-workdays," Knutson says. "This paper suggests it's not just the extreme cases of irregular bed times, but even a more modest difference between weekends and weekdays of an hour or two seems to be associated with health outcomes like obesity."
All workdays should begin at 10AM.