Fast For Father Not For Men
Matthew 6:16

    For what reason would anyone fast for God? Why would anyone deprive themselves of anything their physical bodies needed on account of God? Of what benefit to God does one give when one does not allow themselves to have what they already have access to? We need to ask God about this and see what he has to say:

Isaiah 58:3-9 GNB The people ask, "Why should we fast if the LORD never notices? Why should we go without food if he pays no attention?" The LORD says to them, "The truth is that at the same time you fast, you pursue your own interests and oppress your workers. 4 Your fasting makes you violent, and you quarrel and fight. Do you think this kind of fasting will make me listen to your prayers? 5 When you fast, you make yourselves suffer; you bow your heads low like a blade of grass and spread out sackcloth and ashes to lie on. Is that what you call fasting? Do you think I will be pleased with that? 6 "The kind of fasting I want is this: Remove the chains of oppression and the yoke of injustice, and let the oppressed go free. 7 Share your food with the hungry and open your homes to the homeless poor. Give clothes to those who have nothing to wear, and do not refuse to help your own relatives. 8 "Then my favor will shine on you like the morning sun, and your wounds will be quickly healed. I will always be with you to save you; my presence will protect you on every side. 9 When you pray, I will answer you. When you call to me, I will respond. "If you put an end to oppression, to every gesture of contempt, and to every evil word;

Fasting in the law of Moses  actually shadows sacrificing one's  surplus or even one's own necessary means in order to help someone in need.  It implies risking public ridicule by speaking up for the speechless one. It implies standing up for and risking ones own neck for those abused, suppressed, or exploited. It implies giving out food to those in need. It implies helping those homeless by giving them a home. It implies taking in the fatherless boy and clothing the naked, and if one's own brother is in need, it implies that we not hide from him, but help him in his tribulation. 
    Those hypocrites who fast in order to be seen by men seek a reward from men, and they do gain that reward, but it will be of no value to them when the wrath of God comes. Our Father in the heavens will allow our light to be seen, no matter how discreet we are, in our fasting, and more comprehensively, with regard to our righteousness.

Proverbs 13:7 GNB Some people pretend to be rich, but have nothing. Others pretend to be poor, but own a fortune.

    Fasting can also have to do with what we allow in our minds.

Matthew 16:5-12 GNB When the disciples crossed over to the other side of the lake, they forgot to take any bread. 6 Jesus said to them, "Take care; be on your guard against the yeast of the Pharisees and Sadducees." 7 They started discussing among themselves, "He says this because we didn't bring any bread." 8 Jesus knew what they were saying, so he asked them, "Why are you discussing among yourselves about not having any bread? What little faith you have! 9 Don't you understand yet? Don't you remember when I broke the five loaves for the five thousand men? How many baskets did you fill? 10 And what about the seven loaves for the four thousand men? How many baskets did you fill? 11 How is it that you don't understand that I was not talking to you about bread? Guard yourselves from the yeast of the Pharisees and Sadducees!" 12 Then the disciples understood that he was not warning them to guard themselves from the yeast used in bread but from the teaching of the Pharisees and Sadducees.

 One of the laws given by Moses was that after the Passover lamb was eaten by the children of Israel, they fast for seven days, by eating nothing other than unleavened bread. If the unleavened bread shadows the Word of God, then during this period of time, should we not fast from the teachings of men, and allow only the word of God into our hearts? Why not read God's word for seven days without watching the idiot box, or without listening to the radio, or without reading magazines, or news papers? How about doing this without allowing others to know of it, aside from our immediate family? How about having a seven day Bible reading marathon, attempting to get through the entire Bible in seven days straight, once a year?

Exodus 12:14-20 GNB You must celebrate this day as a religious festival to remind you of what I, the LORD, have done. Celebrate it for all time to come." 15 The LORD said, "For seven days you must not eat any bread made with yeast---eat only unleavened bread. On the first day you are to get rid of all the yeast in your houses, for if anyone during those seven days eats bread made with yeast, he shall no longer be considered one of my people. 16 On the first day and again on the seventh day you are to meet for worship. No work is to be done on those days, but you may prepare food. 17 Keep this festival, because it was on this day that I brought your tribes out of Egypt. For all time to come you must celebrate this day as a festival. 18 From the evening of the fourteenth day of the first month to the evening of the twenty-first day, you must not eat any bread made with yeast. 19 For seven days no yeast must be found in your houses, for if anyone, native-born or foreign, eats bread made with yeast, he shall no longer be considered one of my people." 20 (SEE 12:19)