Simple equation reveals your perfect bedtime

It seems the “early to bed, early to rise” proverb has a new benefit to add to the payback of being “healthy, wealthy and wise.”

And that’s a lower BMI.

Previous studies have shown that not getting enough sleep is linked to obesity because it disrupts weight-control hormones.

But according to a new study out of UC Berkeley, getting the right amount of sleep isn’t the entire problem. When the lights are turned out also seems to make a difference.

This theory rang true after researchers tallied results from a 15-year study of more than 3,300 adults and teenagers. They specifically tracked teenagers from the onset of puberty through young adulthood, and found that those who stayed up late during the week were more likely to gain weight compared to their peers who hit the hay earlier.

In fact, after looking at results, for every hour of sleep lost, the participants’ BMIs increased 2.1 points (which roughly translates to 10 lbs). And this 2.1-point increase was just for a 5-year period. Which means that, over the course of a decade, staying up late could lead to a whopping 20-pound weight gain.

I know it’s easier said than done to reset your internal body clock. But here’s a simple formula that can help you figure out how you can do it.

While some people need less sleep than others, most of us should be getting between 7.5 and 8 hours a night. So, in order to figure out the best hour to pack it in, work backward from when you need to wake up in the morning.

If you need to be up by 6:30 am, subtract 8 hours and turn out the light at 10:30pm. And as a general rule of thumb, always try to be in bed before midnight.

If you can follow that schedule for two weeks, you’ll naturally begin to wake up right around when your alarm is to go off.  Consistency is the key to success — and for keeping the pounds off.