Fasting is a sacred and special sacrifice; it is for the Lord, not for human approval or notice. In Matthew 6:16-18, Jesus cautions those who choose to fast for human admiration and approval, "When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to men that you are fasting, but only to your Father, who is unseen; and your Father, Who sees what is done in secret, will reward you."

Please understand the spirit of Jesus' message. He is not saying that absolutely no one should know when we are fasting. In fact, it is very important to have a trusted Christian friend or a network of Christian friends who can pray for you while you are fasting. Jesus is cautioning against fasting for the approval and notice of man, just as He cautions against giving for sheer spectacle.