You’ve heard of light sleepers, right? Well, according to a new study, teens who go to sleep earlier tend to be…lighter.

Researchers combed through 21 years’ worth of data from the National Longitudinal Study of Adolescent Health. They found that teens who went to bed earlier tended to be thinner than their night-owl peers. In fact, for every extra hour teens stay awake, they gain 2.1 points on the body mass index. In fact, nothing was as critical to a healthy weight—not screen time, exercise or the total sleep teens get—as their standard bedtimes. (New York Daily News)