 "Want a longer life? Why sleep may matter more than diet or exercise")
Sleep is often the first thing we sacrifice when life gets busy. But new research suggests that this trade-off may come at a far higher cost than many realise. A major US study has found that insufficient sleep is closely linked to reduced life expectancy, ranking just behind smoking as a predictor of how long people live.
Researchers from Oregon Health & Science University analysed sleep patterns and life expectancy across thousands of US counties and found that routinely sleeping less than seven hours is strongly associated with a shorter lifespan. The study, titled Sleep insufficiency and life expectancy at the state-county level in the United States, 2019–2025, was published in the journal SLEEP Advances and tracked trends from 2019 to 2025.
Most notably, sleep showed a stronger link to life expectancy than diet, exercise or social isolation, suggesting that sleep deserves far more attention than it usually gets.
What did the study examine?
The researchers analysed data from the US Centers for Disease Control and Prevention’s Behavioural Risk Factor Surveillance System, covering more than 3,100 counties across all states. They compared county-level life expectancy with the proportion of adults getting less than seven hours of sleep per night between 2019 and 2025.
To strengthen the findings, the analysis adjusted for other well-known factors that affect lifespan, including smoking, physical inactivity, diet-related indicators, unemployment, education and health insurance status. Even after accounting for these variables, sleep emerged as a key factor.
How strong is the link between sleep and life expectancy?
According to the study, counties with lower levels of sleep insufficiency consistently recorded higher life expectancy year after year across most US states. By 2024, every single state analysed showed a statistically significant association between inadequate sleep and shorter lifespan.
When lifestyle factors were compared side by side, insufficient sleep was more strongly linked to reduced life expectancy than diet quality, lack of exercise or social isolation. Only smoking showed a stronger association with dying earlier.
How much sleep counts as ‘enough’?
For this analysis, “sufficient sleep” was defined as at least seven hours per night, based on recommendations from the American Academy of Sleep Medicine and the Sleep Research Society.
People who regularly slept less than this threshold were classified as sleep insufficient. Importantly, the study focused on habitual sleep patterns rather than occasional late nights.
Why would poor sleep shorten your life?
Decades of research show that inadequate sleep disrupts cardiovascular health, weakens immune function, affects glucose metabolism and impairs brain health. Poor sleep is also linked to higher risks of obesity, diabetes, depression and heart disease.
The researchers stress that diet and physical activity remain important for health. The key takeaway is not to abandon healthy eating or exercise, but to stop treating sleep as a negotiable leftover of a busy day. From a longevity perspective, skipping sleep may be costlier than skipping the gym.