A new study published in the journal SLEEP Advances used national data from the U.S. Centers for Disease Control and Prevention, covering all counties in the country between 2019 and 2025, to analyze how sleep insufficiency relates to life expectancy. Sleep insufficiency is defined as fewer than seven hours of sleep per night. Using mixed-effects modeling that controlled for other mortality predictors such as smoking, diet, physical inactivity and social isolation, the researchers found a significant association between insufficient sleep and a shorter life expectancy. Only smoking had a stronger relationship with mortality. The study indicated that getting adequate sleep was more important to life expectancy than diet and exercise. The results were consistent across income levels, healthcare access and geographic locations.