A Single Health Factor Could Predict Longevity More Than Diet Or Exercise

If you’re hoping to live a longer, better life, eating well, exercising, and avoiding habits like smoking are great places to start. 

But according to a paper published in SLEEP Advances, the amount of shut-eye we get at night may be more strongly linked to our projected longevity than even diet and exercise. 

This isn’t to say that neither of those metrics matter: they definitely do. Scientists think that improved diets could add 10 years to the lives of people in the UK, while a review of studies found that being physically active could increase our lifespan by about two to four years as a “conservative” guess.

As sleep physiologist Andrew McHill, who was involved in the new research, said: “I didn’t expect [sleep] to be so strongly correlated to life expectancy”. 

What did the study say about sleep and longevity?

The researchers looked at a huge US database of health survey data taken between 2019 and 2025, alongside state-level life expectancies.

They compared those figures by area while also looking for participants’ self-reported sleep duration. 

Insufficient sleep (characterised as less than seven hours of sleep a night) was “significantly negatively correlated with life expectancy in most states from 2019 to 2025”, the paper reads. 

This finding stood even when researchers looked at other variables such as diet, exercise rates, employment status, and education levels. 

Only smoking seemed to be more of a significant risk factor when it came to longevity.

McHill told Oregon health & Science University: “We’ve always thought sleep is important, but this research really drives that point home: people really should strive to get seven to nine hours of sleep if at all possible.”

Healthy diet and exercise still matter – but don’t neglect sleep in the pursuit of both

This absolutely doesn’t mean that a healthy diet and exercise, which decades of research have proven are key for great health, are optional if you want to live longer.

The study didn’t definitively prove that insufficient sleep led to the early deaths with which it was associated. 

But McHill noted that getting enough sleep can help to improve our heart health and boost our immunity, and suggested we shouldn’t simply dismiss it as a “nice-to-have” extra.

“This research shows that we need to prioritize sleep at least as much as we do to what we eat or how we exercise,” he said. “Sometimes, we think of sleep as something we can set aside and maybe put off until later or on the weekend.”

But “getting a good night’s sleep will improve how you feel but also how long you live,” he ended.

Previously, a 2025 paper suggested that those who felt they had to choose between sleep and a workout saw better health benefits from their snoozy side win.