How Your Bedtime Affects Your Waistline

Updated on 10/2/2015 at 12:12 PM

POPSUGAR Photography | THEM TOO

If you're a night owl who can't seem to get to bed at a reasonable time, this may convince you to hit the hay earlier: a new study shows that later bedtimes are linked to weight gain.

The study, published in Sleep, analyzed data from 3,300 teens and adults and found that for every hour of sleep the participants lost, they gained 2.1 points on the body mass index (BMI) over five years. The surprising finding? The amount of sleep didn't affect the results — that is, someone who went to sleep late but still got an adequate amount of sleep still gained more weight than those who went to sleep earlier and slept the same amount. The researchers also found that amount of exercise and screen time also didn't mitigate the effects of late bedtimes on weight gain, although the study authors did note that late-night fast-food habits could be a factor. Previous studies have shown that not enough sleep is a contributing factor in weight gain, but this study highlighted the fact that your bedtime matters, no matter what. Bottom line? When you go to sleep, not just how much you sleep, might be an important factor in the number you see on the scale.