I had just purchased and starting reading the book when this was first posted here. I haven't spent much time to look into either side, but I stopped reading the book because I felt like I may be filling my mind with false information. And I bought it in the first place thinking an expert was going to teach the most important things we know so far about sleep. It bums me to think about this.
I can summarize what both the original author, and what the person wrote criticizing agree on. Yes, sleep is required. Get enough sleep that you feel rested.
A lot of the critique was around the 8 hours, and the conclusions about what happens if you get less.
Anecdotally, I never sleep 8+ hours. I also get up without an alarm clock every single day. I'm not going to stress that I normally sleep ~7 hours and feel rested when I wake up. I know on the rare occasions if I get less than 6 hours, I'm going to be really tired that night.
One problem with this approach is that if you've always had dysfunctional sleep, you don't understand what "feeling rested" really means. I had undiagnosed sleep apnea until my late 20s, and it was insane what a difference getting a CPAP made. I literally couldn't conceptualize how fatigued I had been all of my life until I had something to compare it against, and when I finally started getting restorative sleep my whole life changed.
Yup, exactly this. It feels normal to you, because that's how it's always been and no matter what you do, you never actually get a good night's sleep. I dealt with severe obstructive sleep apnea from my late teens to my mid twenties. I have no idea how I was able to study and graduate college, looking back. I got a CPAP and later corrective surgery and it's completely changed my life. Think about how you feel when you get half your normal sleep. Looking back, that's how I felt every single day.
not OP, but if you have sleep apnea, you typically snore very loudly. You may not realize you're doing this because you're asleep and alone, but if you sleep with someone, they will definitely let you know something is wrong and a dr will tell you to get a CPAP machine.
It depends on the type. The most common type, Obstructive Sleep Apnea sounds way worse than loud snoring. If you've ever heard it, it's like the person is suffocating while they sleep (because they almost are).
It's not so much the false information (lack of evidence for major claims) but the amount of anxiety it causes around sleep which is very counterproductive. The author makes it seem like you will never recover from the deleterious health effects from not getting enough sleep.
I read all of it, and enjoyed it. I think its worth reading. At the very least, it will get you to appreciate sleep as an open biological question. The critiques were about his data presentation and stuff like that, not the topic of sleep itself.
[1] https://guzey.com/books/why-we-sleep/