Thou mayest as well expect to grow stronger by always eating as wiser by always reading. Too much overcharges Nature, and turns more into disease than nourishment. 'Tis thought and digestion which makes books serviceable, and give health and vigor to the mind. - R. Buckminster Fuller
         

Books and food are both good things, but more is not always better.  Nothing is actually good for us unless we make good use of it.  Our bodies have to digest food, extracting the nutrients, before it can help us grow.  Similarly, reading by itself won’t improve my mind, I need to think deeply enough to extract the ideas from the book before they can become part of my understanding.