I couldn't write books if I didn't read as much as I do. Even if I'm on a deadline I'll be reading something - I've even been known to put reading into my pomodoro breaks.
Of course, there are difficulties with reading-while-writing. The worst being that you're halfway through a storyline when you realise that it's remarkably similar to one written by someone else. You stop writing; panic; try to re-imagine your entire plot. (My advice: forget about it. Whatever you're writing, there will always be someone in the world who's written something similar.)
Or there's the one where you realise you've spent a week writing in the style of the author you've just read. (My advice: go back and delete all those bits. Your own voice will inevitably return and you'll be left with a strange and stylistically incongruous outburst in the middle of your manuscript that your editor is bound to spot.)
But these pitfalls are minor compared to the idea of a life without books. Read! Read! Read! ALWAYS!