The new CDC survey provides a baseline of school-start times against which scientists will be able to track any changes, says Daniel Lewin. He is a doctor and sleep expert at the Children’s National Health System in Washington D.C.
Starting school too early forces teens to lose a large chunk of what’s known as REM — or rapid eye movement — sleep. This type of sleep helps teens (and everyone else) control their moods. But that’s not the only problem. Too little sleep also has been linked with an increased risk of obesity, depression, drug use and other problems.