St. John the Forerunner and Baptist of Christ, who fasted his entire life in the desert (source)
"Fasting is a commandment of God. Because of this, we should also fast, my children. I have not neglected fasting in my 70 years. My mother taught me fasting from childhood. I am not being a hypocrite, my children, when I fast, but I am doing that which my parents taught me and that which I keep until today, my children. Fasting has never brought sickness upon me.
Physicians and Bishops say that frugal fasting is very beneficial to man. Once, a doctor told me: "Father, don't eat for five days, nor even drink a drop of water, because we will do a test to see what is going on with your body." Therefore I fasted for five days. It had done great things to me. How much more are we benefited when we fast for our soul! Because within our body inhabits an eternal soul. Therefore, let us take care for our soul, which is truly an immortal thing.
Let us fast, my children, do not listen to those who say that fasting is nothing, and that this is something from monks. This is not from monks, my children, forgive me, God says this. The first commandment of God is fasting, and our Christ fasted.
We can say that we are fasting, and eat so much. Now, what fasting are we doing, my children? When we eat, forgive me, so much food, even if it is without oil. It is sufficient that man have his health and the desire to fast.
Once, someone came to me and said: "My priest, they told me that fasting doesn't exist." "And who told you that there was no fasting? Go tell the Priest to open the Bible and see that which discusses fasting: 'without prayer and fasting' (Matthew 17:21, Mark 9:29), which our Christ says, and other things.' And the demons, and sicknesses, and all the passions are cast out with fasting. The Holy Forerunner, what did he eat in the desert? What did the Venerable David eat? With an antidoron, he passed the whole week in his cell of asceticism."
-Elder Iakovos Tsalikis of Evia
(amateur translation of text from source)
Through the prayers of our Holy Fathers, Lord Jesus Christ our God, have mercy on us and save us! Amen!