I do a lot of consulting, and as a result I am often (honestly, almost always) work substantially more than 'full time'
I have more aha moments in the shower when I'm working intense hours, not less. My theory on this is that more exposure to the problem space gives the subconscious mind more to chew on.
I genuinely have no regrets about working a lot as I've found the personal and professional growth to have been very satisfying. I've launched far past most people my age in terms of skill and experience by simply putting in more hours than they have.
Regarding health, it should be noted I don't drink or smoke at all and never did. And my naturally eating habits include zero junk food. I haven't felt any negative health effects from my work/life balance, but I am fairly confident that's largely due to those healthy habits.