This can apply to ungodly spiritual things as well as unhealthful food and drink. God has called us to keep our bodies healthy. This is not because God doesn't want to heal us, it's solely because we are not responding to what God has told us is good for us. This is an example of knowingly contaminating the temple of God. Smoking is another example.
Drugs are another.
And just as Jesus cleansed the Temple in Jerusalem, so ought we to cleanse the temple of our bodies from all ungodly things, even thoughts. A lack of spiritual response to God, can lead to an irresponsible physical act and bring a physical illness upon ourselves. I believe that we need to truly pray about our attitudes in the light of how we respond to God. Our understanding of this is part of our response to God's call to us. Just as Hanna and Samuel believed God's call to them through Eli, so should we respond to God's call to us through Paul and David's writing.