If there was ever a reason to stop pressing the snooze alarm, this could be it. Researchers behind this study say its the first ever to report that the time of day that you're in the light could impact how much you weigh. Here's how it works:
Researchers at Northwestern University's School of Medicine found that people who got most of their exposure to light early in the day had a significantly lower body mass index than those who got most of their light later in the day -- in fact, they found light impacted about 20 percent of someone's BMI.
BMI is a measure of body fat, based on a person's height and weight.
So why does this happen? You might think it's because people who get up earlier are working out but researchers said that wasn't the case. They said light exposure influence was independent of activity level, calories, sleep pattern, age or season.
Researchers said the key time to get bright light is between 8 am and noon -- and if you get just 20 to 30 minutes during that time, it can impact BMI.
But there's a potential catch -- scientists say indoor light is usually not strong enough to reach the light level of influencing your BMI.
Time of day mattered, too because researchers said early morning light waves have more of the blue light that is most likely to impact your circadian rhythms -- that's your sleeping and waking cycle -- and experts say those rhythms plays an important role in regulating metabolism so, while that afternoon sun feels good, it may have less of an impact.
Copyright 2014 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.