ATLANTA — A new study suggests coffee drinkers may need to stop consuming caffeine nearly nine hours before bedtime to get the best night’s sleep.

The study, published in the journal Sleep Medicine Reviews, found that consuming caffeine closer to bedtime could cost people up to 45 minutes of good rest each night.

Previous studies have also advised waiting about 90 minutes after waking up before having the first cup of coffee.

That recommendation is intended to help balance hormones, particularly cortisol, which regulates stress.