Thanks for the ping!
Not many Protestants I know practice fasting, but some do. As far as I know, it is neither required or prohibited.
However, should one decide to do so, it is looked upon as an extension to prayer. Fasting, along with prayer, is a way to go past the normal daily relationship with God and seek an even more close, personal meeting.
Instead of the usual head bowed in prayer type worship, fasting allows you to stand up and give God a great big hug, so to speak.
And He lets us do it!
"However, should one decide to do so, it is looked upon as an extension to prayer. Fasting, along with prayer, is a way to go past the normal daily relationship with God and seek an even more close, personal meeting."
That's exactly what it is. Most people who fast during Great Lent, and for that matter on Wednesdays and Fridays and the other fast periods, reltively soon come to experience a certain clarity of the eye of the soul, so that the "dark glass" becomes a bit less translucent. But there are real here and now benefits. Fasting does teach us to focus on what is important in our daily lives. It allows one to put the regular hassles of life in a proper perspective and brings an enhanced equinimity to our lives.
"Fasting is the champion of every virtue, the beginning of the struggle, the crown of the abstinent, the beauty of virginity and sanctity, the resplendence of chastity, the commencement of the path of Christianity, the mother of prayer, the well-spring of sobriety and prudence, the teacher of stillness, and the precursor of all good works. Just as the enjoyment of light is coupled with healthy eyes, so desire for prayer accompanies fasting that is practiced with discernment." +Isaac the Syrian