[Tenoke]

>The absence of evidence that 6 is much worse than 8 hours is not evidence that 6 is not much worse than 8 hours.

It's not absense of evidence as in hasn't been tested - they have been compared and it doesn't really come off as worse or at best only a little worse (and in some cases better than 8).

>It doesn't matter that much in this case because we already agree that it's worse - the question is how much worse.

Who is this 'we'? My whole point is that people have this assumption and keep looking for ways to justify it even when confronted with evidence that it might not be the case as in the study posted here or the systematic review I posted.

>and here we see exactly the adverse health outcomes you cited (and a lot more that you didn't cite) from [1].

But we don't see that. What I cited was that the evidence doesn't even suggest worse outcomes at 6 vs 8 hours in the biggest analyses out there.

[Pyramus]

I don't understand. The study you cited, a meta-analysis, reviews the adverse effects of short and long sleep on

* Mortality

* Incident cardiovascular disease

* Incident type 2 diabetes

* Mental health (incident depression)

* Brain health (incident cognitive disorders)

* Cognitive function

* Falls

* Accidents and injuries

and six other outcomes. The authors conclude:

> Conclusion

> A comprehensive body of evidence supports the presence of a U-shaped association between sleep duration and health outcomes in adults. Dose–response curves showed that the sleep duration that was most favourably associated with the health outcomes that were examined was around 7–8 h per day in adults, with no apparent modification of the effect by age in the few studies that looked at it.

[Tenoke]

I specifically cited the actual results from the meta-analysis. In the conclusion and abstract they seem to mostly talk about 7-8 vs really short or longer sleep but when you look at the analysis there's barely any adverse effects at 6 (and indeed 6 is better than 8 and only a tiny bit worse than 7 on the most important thing from most studies - all-cause mortality).

Yes, of course sleeping, say, 2 hours a night is too little. My claims and quotations were about 6 hours, which is roughly what the people in OP slept, too.

[Pyramus]

It seems to me you are picking one outcome, all-cause mortality (link to the study in question with nice dose-response curves [1]) but ignoring cardiovascular disease, type 2 diabetes, brain health, cognitive function, falls, accidents and injuries, and obesity?

> My claims and quotations were about 6 hours, which is roughly what the people in OP slept, too.

It's not clear how comparable the numbers are. The study from OP [2] reports sleep as measured by actigraphy (5.5h), time in bed (8h) and self-reported sleep (7.2h). What the meta-analyses most likely have studied (I haven't checked) is self-reported sleep.

[1] https://www.ahajournals.org/doi/pdf/10.1161/JAHA.117.005947

[2] https://economics.mit.edu/files/16994

[Tenoke]

I cited 4 outcomes, starting with both the most important one and the one with most studies and subjects behind it. There wasn't an outcome where the big negative effect is there at 6.

You are proving my point - even when presented with data against the 8 hours myth you try to twist it in every way to confirm your prior belief and wouldn't even consider if the data might just be correct.