We’ve all stayed up scrolling, binge-watching, or catching up on work. But biohacker and longevity entrepreneur Bryan Johnson has warned that irregular sleep may be just as harmful as not getting enough sleep at all.
Johnson, who founded Project Blueprint, cited a study of over 88,000 adults showing that erratic sleep schedules are linked to 172 diseases — including liver and metabolic disorders. His warning: consistency is as important as duration when it comes to sleep.
What did the study find?
In a post on X, Johnson referred to a long-term study that tracked 88,461 adults using wearable devices over nearly seven years. The research linked inconsistent sleep — even by just 60 to 90 minutes — to a 1.5-times higher risk of liver disease.
Almost half the 172 diseases studied were more strongly associated with irregular sleep timing than short sleep duration. The study used accelerometers for accurate tracking of sleep traits.
Irregular sleep is just as bad as getting less sleep. Both are linked to the risk of 172 diseases. 42 showed more than doubled risk with bad sleep. Almost half of these diseases were associated with irregular sleep. Things like inconsistent bed times, late sleep hours, and… pic.twitter.com/vCFsreds9T
— Bryan Johnson (@bryan_johnson) September 16, 2025
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Why is irregular sleep so harmful?
Experts have long emphasised the importance of sleep quantity. But the study highlights that timing matters too. Delayed or erratic sleep affects circadian rhythms, liver function, metabolic health, and more.
Bryan Johnson noted that our bodies crave predictable rhythms, and disruption can affect everything from glucose regulation to inflammation pathways.
What habits are causing the damage?
From midnight binge sessions to late-night emails, modern routines disrupt sleep timing more than we realise. Even consistent total hours don’t help if the timing shifts regularly.
Johnson’s takeaway: your liver and metabolism don’t just care about “how much,” but “when.”
What can you do to fix your sleep routine?
- Keep sleep and wake times consistent — even on weekends
- Avoid blue light (screens) at least one hour before bedtime
- Stick to regular meal times and avoid late-night snacking
- Track patterns using wearables or simple sleep apps
Who is Bryan Johnson and why does it matter?
Founder of Braintree (acquired by PayPal) and neurotech firm Kernel, Johnson is best known for Project Blueprint — a radical self-experiment to slow biological ageing. He follows a tightly controlled routine involving dozens of health markers.
His voice carries weight in the longevity space, and his warning about sleep rhythm being as damaging as sleep loss is a wake-up call for modern lifestyles.
For more health updates, follow #HealthWithBS
This content is for informational purposes only and is not a substitute for professional medical advice.

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