According to what is stated above, the best word that completes the analogy is “read” of course. But there is also the idea that “books” can be “eaten” since there are phrases such as “all-you-can-eat books” or “bookworms”. The analogy works since both things you can eat: food and books (in a metaphorical way). But it does not work the other way round: you can not read food.
