Do You Have' Social Jet Lag(社交时差)？
People who have different sleep patterns on the weekends than they do during the work week may experience “social jet lag”. For every hour of social jet lag, the risk of being overweight or obese rises about 33%,says researcher Till Roenneberg, PhD, a professor at the Institute of Medical Psychology at the University of Munich.
Roenneberg, who created the term, says social jet lag is caused by the shift in sleep schedule that many people experience on their days off, compared to work days.
It goes like this: You don't have to get up for work so you don't take trouble setting the alarm. That means you get up an hour or two later than you might during the work week.
As a result, many people get more sleep on their days off than they do during the week, and they sleep on a slightly different schedule-a schedule that is closer to their body's natural rhythms.
“The behavior looks like most people on a Friday evening fly from Paris to New York or from Los Angeles to Tokyo and on Monday they fly back. Since this looks like almost a travel jet lag situation, we call it social jet lag.” he says.
When you arrive in a different place, the sun is coming up and setting at a different time, and your body can reset its own clock to match. With social jet lag, the schedule disturbance is lasting because a person stays in the same place. “They have to live a life almost in a different time zone in comparison to their biological clock,”Ronneberg says.
A. Sleep 
he thinks ,should get more respect.
B. He guesses that it affects about two-thirds of the population.
C. A key difference between travel jet lag and social jet lag, however, is light.
D. And depending on what type of person you are, the difference can be significant.
E. Roenneberg explains switching sleep schedules this way feels like changing time zones.
F. A new study shows this shift in sleep schedule is connected with obesity.
G. You may also push your bedtime back so you can go out with friends.
