Research
Mixed
Habitual sleep duration of 9 hours or more per night is associated with a 30% increased risk of all-cause mortality compared to the reference range of 7-8 hours.
Aim for 7-8 hours of sleep per night. Sleeping consistently 9 hours or more is associated with a 30% higher risk of death. If you consistently need this much sleep, it may be a sign of underlying health issues worth investigating with a doctor.
StrongSupportsHIGH confidence
Long duration of sleep (27 cohorts from 16 studies, n = 1,382,999 with 112,566 deaths) was associated with a greater risk of death (1.30; [1.22 to 1.38]; P < 0.0001)... Pooled analyses indicate that... long sleepers (commonly > 8 or 9 h per night) a 30% greater risk of dying than those sleeping 7 to 8 h per night.
Why this rating
Systematic review and meta-analysis of 16 prospective studies with over 1.3 million participants.
Source
Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies
Francesco P. Cappuccio et al. · SLEEP · 2010
Meta-analysis · 16 studiesCited 2,187×
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