Especially when I'm hacking my own, non-renewable, non-refundable body I'd want more than a bit of scientific proof that a) it works and b) it won't mess me up.

Especially when I'm hacking my own, non-renewable, non-refundable body I'd want more than a bit of scientific proof that a) it works and b) it won't mess me up. Whereas your regular self-help book might just wreck your bank account (at the worst), some of the things in this book might do a lot worse things. Yes, they might not, too. But are you willing to take those risks? (Again, the slow-carb diet and the kettlebell workouts are probably amongst the least controversial parts of the book) And yes, I've read the book, most of the "hacks" have been done by Tim on himself, sometimes with a with/without methodology. Not really bad and actually something that everyone who modifies his lifestyle should do. But that still doesn't replace blinded studies, never mind that he very rarely states how many "hacks" he's been doing at the same time. And never mind that he's been quite athletic for most of his life, so a lot of the techniques won't work that well for your average pudgy nerd. It's not a very expensive book, on the other hand. But if someone buys it, I'd recommend taking everything cum grano salis and do your internet research before embarking on a "hack", especially if it means taking supplements (e.g. the bro-sciency ECA stack).