How much sleep do you need? The CDC is coming out with new guidelines next year, but a spate of recent research suggests that seven hours is close to the magic number, not eight, reports the Wall Street Journal. Because requirements change from person to person, however, experts suggest spending time away from the alarm clock, caffeine, alcohol, and your computer to let yourself both fall asleep and wake up naturally. If you feel good the next day, you’ve hit the sweet spot.
A sampling of that seven-hour research: A study of 1.1 million cancer patients connected roughly seven hours of sleep to lower mortality; another study revealed the same among 450 elderly women; and another put five healthy adults in a simulated Stone Age for two months (no clocks or electricity) and showed the average night’s sleep was 7.2 hours. Studies also show seven hours keeps the brain and body in its best working condition, while too much shuteye has been linked to diabetes, obesity, cardiovascular disease, and higher mortality rates. On the flip side, too little sleep leads to a sluggish brain, poor health, and weight gain. The CDC is assessing all this and more for its pending recommendation. (Another study has shown seven hours of sleep can help you eat less.)