Looking forward to sleeping in this weekend?
Don't do it, you could gain weight.
German researchers are looking at "social jet lag."
It's similar to jet lag when you travel.
People can get "social jet lag" when they wake up at one time during the week, and sleep in on the weekends.
Scientists looked at people 16 to 65-years-old.
They discovered sleeping patterns, along with other factors, like age and gender, are a good predictor of body weight.
One take-away from the study, according to experts, is to try to maintain a regular sleeping schedule.
It might be good for your health in the long-run.