Over and over I have experienced being fed by God's Word. Whether it's during morning devotions, working on my Bible study lesson, in church on Sunday morning, listening to christian radio in the car - God's Word speaks right to my soul. The Holy Spirit nudges me and says, "This message is for you. It will fill you up. Listen." If I am hungry I will be fed by God's Word.
Sometimes, though, I'm too full of junk food. I have fed myself meaningless stuff - TV, magazines, gossip, books, etc. and I don't realize I'm hungry. Unfortunately I substitute junk food for the meat of the gospel.
Other times my busy schedule crowds out my devotion time. I know that I should take the time to eat, but I'm just too busy. And just like my physical body wears down, and I get grumpy, and I'm so hungry that I don't know what to eat because nothing sounds good, my spirit wears down when I don't take time to be in God's Word.
When I'm busy I'm also tempted to eat on the run - take some food with me to eat in the car, or drive through a fast food restaurant. While this food helps with my hunger for a while, it's rarely nourishing, and it doesn't really fill me up. I'm often tempted to get my spiritual nourishment as I go. Now, I don't mean that I shouldn't listen to Christian radio in the car - but I can't substitute that for devotional time. Just as it's important to sit down at the dinner table, take my time when I eat, and to eat at regular meal times it's also important to have regular times for devotions and Bible study and to have a special place to do that.
Are you spiritually hungry? Start by expecting God to feed you with His Word. Spend time in devotions. (If you need a devotional, Max Lucado has several good ones!) Start going to church. Then keep a journal of the verses that God uses to fill you up - because He will fill you up!