More, in fact, than any of us will ever have time to read, even if summer were endless. What I also will do, like a good nutritionist, is suggest a balanced diet. A well-written biography can read as well as any novel. A collection of essays can entertain while providing insight. Don't take this as a slap at fiction.
Nothing's better than a finely-crafted novel.
Quality fiction can offer as much as non-fiction. I am only proposing moderation and balance. Unlimited chocolate cake, however delicious, is too much. I like to switch back and forth in my reading. I prefer my non-fiction in the morning, with my coffee, when I'm fresher and more inquiring.