Here is a pretty good explanation of why Orthodox Christians fast. It refers to Great Lent(the time before Easter) and this fast (before Christmas) is often called Little lent...
(source:
http://www.goarch.org/en/ourfaith/articles/article8124.asp )
Fasting was practiced by the Lord Himself. After prayer and fasting for forty days in the wilderness, the Lord victoriously faced the temptations of the devil (Matthew 4:1-­11). The Lord himself asked the disciples to use fasting as an important spiritual weapon to achieve spiritual victories (Matthew 17:21; Mark 9:29; Luke 2:37). The example of the Lord was followed by His disciples (Acts 14:23; 27:9; 1 Corinthians 7:5; 2 Corinthians 6:5, 11:27, etc.). What is fasting? Why is it so important? Why does fasting precede such important feasts such as Easter and Christmas?
The importance of fasting depends on its meaning. Many of the Fathers have written on fasting. Among others, St. Basil has left us with most inspired comments on fasting. St. Basil tells us that fasting is not abstaining from food only; it is first of all, abstaining from sin. Grounded in the teaching of the Fathers, the Church in its hymnology describes fasting as the mother of chastity and prudence, as the accuser of sin and as the advocate of repentance, the life worthy of angels and the salvation of humans (The Lenten Triodion, trans. Kallistos Ware, London 1978, p. 195). Fasting becomes all of these when observed in the proper spirit.
First of all, fasting is abstinence from food. By detaching us from earthly goods and realities, fasting has a liberating effect on us and makes us worthy of the life of the spirit, a life similar to that of angels. Second, fasting, as abstinence from bad habits and sin, is the mother of Christian virtues, the mother of sound and wholesome thinking; it allows us to establish the proper priority between the material and spiritual, giving priority to the spiritual.
Fasting is the advocate of repentance. Adam and Eve disobeyed God; they refused to fast from the forbidden fruit. They became slaves of their own desires. But now through fasting, through obedience to the rules of the Church regarding the use of spiritual and material goods, we may return to the life in Paradise, a life of communion with God. Thus, fasting is a means of salvation, this salvation being a life we live in accordance with the Divine will, in communion with God.
Because of the liberating effect of fasting, both material and spiritual, the Church has connected fasting with the celebration of the major feasts of our tradition. Easter is, of course, our main feast. It is the "feast of feasts." It is the feast of our liberation from the bondage of sin, from corrupted nature, from death. For on that day, through His Resurrection from the dead, Christ has raised us "from death to life, and from earth to heaven" (Resurrection Canon), Christ, "our new Passover," has taken us away from the land of slavery, sin and death, to the promised land of freedom, bliss and glory; from our sinful condition to resurrected life.
It is most appropriate to prepare for this celebration through a liberating fast, both material and spiritual. This is the profound meaning that fasting takes during the Great Lent. Let us allow ourselves to take advantage of the spiritual riches of the Church. Let us use the precious messianic gifts offered to us through its sacramental life, through its celebrations of the central mysteries of our salvation in Christ. Let us use the spiritual weapons,
"to fight the good fight, to walk the way of fasting, to crush the heads of the invisible dragons, to prove ourselves victorious over sin, and without condemnation to reach our goal of worshiping the Holy Resurrection" (Prayer of the Presanctified Liturgy).
This is the challenge of the Great Lent: to use fasting to obtain the resurrected life, to unite with the Risen Lord. Who could refuse to accept this challenge?
(j/k Stringaling 
That's just wrong....but thanks, I sure enjoyed the pics!! 
