Caffeine consumption timing impacts sleep quality

Research indicates that the timing of caffeine consumption significantly impacts sleep quality. A systematic review and meta-analysis published in Sleep Medicine Reviews analyzed 24 studies, finding that caffeine consumption can reduce total sleep time by an average of 45 minutes and decrease sleep efficiency by 7%. It also increases the time taken to fall asleep and leads to more time spent awake after initially falling asleep, while reducing deep sleep.

To avoid reducing total sleep time, researchers suggest that a 250 ml serving of coffee containing approximately 107 mg of caffeine should be consumed at least 8.8 hours before bedtime. For an individual sleeping at 11:00 PM, this would mean a cutoff time of approximately 2:12 PM. However, these estimates are not universal, as individual tolerance and dosage vary.