God’s Word is spiritual food
God wants us to be strong and healthy not only physically, but also spiritually. We do not need ‘spiritual fasts’. We can have physical fasts in order to gain spiritual power. But in order to become spiritually strong, we should daily feed on the Word. If you do not do it, you get weaker as a believer; you get weaker in your judgments and in your faith.
When we get weaker we must ‘eat’ spiritually; that is what God’s Word is there for: «…as newborn babes, desire the pure milk of the word, that you may grow thereby» (1 Peter, 2:2).