Oh book gluttony is definitely possible. Its when we have an obsession with "a new teaching". There is nothing wrong about wanting to be taught, or learn something new, but when I get to the stage of reading 7 books at the same time, it is as if I am too impatient with the one I am reading, I don't want to miss something "new" in another book. One way of reducing the number of books I read was to start reading classics, i.e. Christian material written more than a hundred years ago. It is virtually impossible to read one page of those books without stopping and meditating on it, whereas with today's Christian books, its easy to read a few chapters, or even the whole book, in a day or two. Classics which have blessed me:
~ Dark night of the Soul, by St John of the Cross
~ The Imitation of Christ by Thomas a Kempis
~ The God of all Comfort by Hannah Smith
All of these are available for free online, so that is great. On the road or on my phone I listen to the podcasts so I get through a book much faster than traditional reading.