Byline: Trevor Butterworth
Waking up early is making us fat.
Are you socially jet-lagged? If you need an alarm clock to wake up, then you probably are. The term, coined by Till Roenneberg, a chronobiologist at Ludwig-Maximilians University in Munich, refers to what happens when your internal body clock wants you to stay asleep but your external social clock wants you to wake up. By getting up with our alarms all week and sleeping late on the weekends, it's like sending our body clock to the West Coast and dragging it back East Monday morning. The result, says Roenneberg, is that "there are people who, caught in a cycle of sleep loss and oversleeping, hardly ever get a normal night's sleep at all."
The problem is that this increasingly describes most of us. If majoritarian rules applied to society, and we weren't chasing the global economy, most people would happily nod off between 12 a.m. and 1 a.m. and wake between 8 a.m. and 9 a.m. Instead, "85 percent of us need an alarm clock to wake up," says Roenneberg, with the result that "two thirds of normal people suffer from one hour or more of social jet-lag, 16 percent two hours, and shift workers considerably more."
Shift work is particularly vicious. Orfeo Buxton, a sleep researcher at Harvard University Medical …