This scripture makes me think about a parent preparing dinner and telling their child: "don't eat too much junk; you'll spoil your appetite". You might roll your eyes at that statement and chalk it up as another parenting cliche. However, this statement of spoiling one's dinner is not only practical, but also echos biblical truth taught by Jesus himself.
With His simple statement in Matthew 5, Jesus was able to demonstrate the entire concept of hunger. When someone hasn't eaten they become hungry, which usually leads to them attempting to satisfy that hunger with some type of food. This person is somewhat easy to feed and satisfy because the more hungry they are, the less picky they are. When someone is truly hungry they are more likely to eat healthy, substantial foods that satisfy and nourish them.
Now compare that person with someone who's been snacking on junk food all day long. This person will be more picky and more difficult to feed because they are not truly hungry. If you try to feed them with healthy foods that their body needs they will probably pass them up. They will eat, but they will likely continue feasting on unhealthy foods which never really satisfy hunger.
Obviously Jesus wasn't speaking of physical hunger and the eating of food, but of being spiritually hungry. We see it all around us: people who aren't interested in what God has to offer because they're so full of carnal and worldly junk. We even see people leaving the church and backsliding for the same reason. If someone is constantly filling themselves with "junk food" they won't turn to God to be filled with the proper nourishment and they might not ever recognize the true hunger in their soul that only God can fill.
The church can not binge on the world's junk food and still be the church God intends us to be. God can't fill a vessel with His righteousness if that vessel is full of something else. The only way He can pour Himself into a full vessel is if that vessel is full of emptiness. If we are going to be temples of the Holy Spirit and be full of God's righteousness, then we must continually empty ourselves in repentance and submission. We must allow Godly sorrow to lead us to repentance and then turn away from what is sinful. We must also submit ourselves to His will for us and empty ourselves of our own desires and plans. Paul describes this as the battle between flesh and Spirit:
Galatians 5:16-17 NKJV -  I say then: Walk in the Spirit, and you shall not fulfill the lust of the flesh.  For the flesh lusts against the Spirit, and the Spirit against the flesh; and these are contrary to one another, so that you do not do the things that you wish.
He is essentially describing the same idea as Jesus. You can't satisfy both the flesh and the spirit; you are either spiritual or you are carnal. If the church is going to be the church and have the impact on our world that God intends us to have, then we must be empty so God can fill us. We must deny our flesh the desires it craves and walk in the Spirit to allow the Spirit to feed, satisfy, and guide us.
God is trying to fill you with his righteousness, peace, and joy. Are you full of emptiness so that you can receive it? Empty yourself today and experience the greatest satisfaction and fulfillment you have ever known.