The Church will tell you that it is essential. Some Orthodox churches will threaten you with excommunication if you don't fast. The Church holds that fasting is "grace-bestowing and life-giving ascetic practice."
Church fasting was inherited form the Judaic worship. In Judaism it is one of those six hundred-plus mitzvot which are pleasing to God.
Early Christians fasted as the Jews did, twice a week, on high holidays and individually as the occasion arose. Fasting is an adjunct to prayer.
In the Orthodox tradition, monastic fasting and laity fasting were different. Later on, the Church regulated fasting requirements to apply to all: this includes fasting every Wednesday and Friday and on specially designated periods (there are three 40-day fasts in an ecclesial year and some minor ones scattered along, varying in intensity and duration, between a few days to two weeks).
The Church prohibited animal products during fasts; it also restricted the use of olive oil as shortening. In some instances, fish is allowed; at others wine is. The Lenten fast is the strictest. Basically, no anmal products or olive oil for 40 days, period.
The purpose of the fast is to control your passions, to be able to say no to evil or to things that might lead you to evil. It is part of the process we call theosis. The food consumed during fasts is bland and not something you will eat with passion, or tend to overeat. You should have one large meal a day and never eat until satiety.
It is portrayed as "healthy" but that's a gross micharacteization vis-avis many metabolic health problems of an average parish population. The fasting rules do not apply to the sick, the travelers and those who are otherwise prevented from complying. Obviously, these can be "stretched" a little.
St. Symeon the Theologian teaches us that humility is more important than self sacrificial fasts and vigils.
To me, the most important fast is the spiritual fast; in other words, fasting from sin and passions otherwise known to lead to evil. If you can attain that kind of a fast, then the physical fast is merely an outward expression of the same.
Your spiritual state greatly affects your ability to fast. In those periods when you are spiritually strong, desires and cravings miraculously disappear and a 40-day period goes by without a hitch. You are neve hungry and you eat minimally. In that state the end of fatsing period is not manifested by gorging yourself on all the foods you missed and hated not having!
However, if you are spiritually weak and troubled, fasts become an endless torture. You constantly long for the foods you cannot have, and often people become bitter and look for any excuse to cheat or avoid it altogether. I confess that I know this from both third party and personal experience.
I guess you could say that fasts are like self-testing. It's like a diabetic pricking his finger to check his blood sugar. It's somewhat painful but it is necessary to know where you are.
Unfortunately, this is not something the Church taught and believed from the beginning and everywhere. In addition, the NT is clear that no food restriction should exist and tat one is not to judge another for what he eats.
Fating rules in its regimented form are a latter-day development in the Church; not something the Church practiced form the beginning. Moreover, what is "passionate" food for some is something others will not touch with a ten-foot pole. To this day I don't know the reaosn animal products are shunned.
I would say there is also another reason for fasting and that is in memory of our Lord Jesus Christ, commiserating, even if only to a symbolic degree, with His immense suffering and sacrifice. He said that His disciples will fast when He is no longer with them.
I believe this is where the Wednesday and Friday fasts come in (the practice of fasting twice weekly is Jewish, except the Jews fast Tuesdays and Thursdays). Some monastics fast on Mondays, as well as on Wednesdays and Fridays, in order to "exceed the righteousness of the Pharisees." I find that somewhat Pharisiacal myself! I thin it is relevant to say also that the monastics do not eat any meat throughout the year.
Thanks for your post on fasting.
Thanks very much, Kosta, for all the info on Orthodox fasting. I was just thinking that there must be some small number of Orthodox who by choice happen to be vegans. I was wondering if they are just sort of "lucky" with this, :) or if the right thing for them to do is to modify their diets to remove something they really like, or something like that. For me to give up animal products would be a big deal, so presumably I would get the full benefit. So, for vegans, I was wondering if they are just considered to be in a constant state of fasting, or .......
You touch on this later in the post when you note that "passion food" for one is repulsive to another. I just didn't know if the Church had put forth enough of a thinking that an answer could be inferred.
I guess you could say that fasts are like self-testing. It's like a diabetic pricking his finger to check his blood sugar. It's somewhat painful but it is necessary to know where you are.
That's a good observation and a good way to look at it.