I recently picked up John Piper's book called "A Hunger for God- Desiring God through Prayer and Fasting." and started to read it.
Here is a description of the book:
A Hunger For God was written to help Christians understand the Biblical nature and purpose of fasting and prayer. In this book, John Piper looks at the phenomena of religious, political, and health-based fasting, which occur around the world, and explains what makes Christian fasting unique. He then discusses the reasons and ways the Bible commends fasting to us. Ultimately, Piper asserts, fasting is a way of expressing to God that he is the supreme hunger of our hearts—that we are starving for him.
You can Read this book online for free if you would like.
If your heart feels like mine, join me in seeking God with all your heart. The more we are satisfied in Him, the more we'll let the things of the world go and we'll find that there is NOTHING more filling than the deep pleasures and love of God.