~Saint Nikolai of Zicha~
Fasting is an essential aspect of practicing the Orthodox life. You cannot be Orthodox and not fast. Unfortunately, many in the Church today do not participate in this grace-bestowing and life-giving ascetic practice. They do this to the loss of their own spiritual and bodily health.But since you are not one of those people, you will need an Orthodox calendar to help you know which days we are to fast, and which type of fasting is prescribed. There are many good ones available: I prefer the one in English published by St. John of Kronstadt Press. But St. Herman of Alaska Press and St. Nectarios Press each produce good calendars in English. They all combine both the Church ("Old") Calendar and the Civil ("Papal", or "New") Calendar.
The Rule of Fasting in the Orthodox Church, by Father Seraphim (Rose) of Platina.
The Meaning of the Great Fast. From the introductory material in the Lenten Triodion. By Mother Mary and Archimandrite [now Bishop] Kallistos (Ware).
Concerning Fasting on Wednesday and Friday, by St. Nikodemos the Hagiorite. An excerpt from the Exomologetarion: A Manual of Confession.
Three Helpful Principles of Fasting: Simplicity, Satiety, and a Litmus Question. An Anonymous Letter to a New Convert.
Rules of Piety: basic and helpful information on fasting. Provides the seasons and guidelines for fasting.
An Answer to a Question About Sexual Abstinence During Fasting Periods, by Archbishop Chrysostomos.
On the Spirit of Gluttony. Book V from the Institutes of St. John Cassian.
The Catechetical Homilies and Testament of St. Theodore the Studite, Homilies 47 (Concerning Fasting, Dispassion, and Purity) and 48 (Concerning Now We Should Adorn Our Eternal Habitation with Virtue).
Various Replies to Questions on Fasting, from Orthodox Tradition.
Thoughts on Fasting and Temperance, by Archimandrite Sebastian Dabovich.
When Are We to Fast?: Midnight-to-Midnight, or Vespers-to-Vespers. From The Shepherd, Vol. XV.
Fasting and the Church Year, helpful information from the Greek Orthodox Church of the Transfiguration in Lowell, MA.
Introduction to the Philokalic Book of St. Gregory of Sinai. Covers a range of topics including prayer and fasting. From Elder Basil of Poiana Marului: Spiritual Father of St. Paisy Velichkovsky.
How Should We Conduct Ourselves During Meals?: Chapter 1 from How to Live a Holy Life, by Metropolitan Gregory of St. Petersburg (1784-1860).
On Fasting: Ch. VIII from Field Flowers, by St. Paisy of Neamt.
Reasons to Fast by Fr. Alexander Lebedeff
Fasting From Iniquities and Foods - By the Rev. George Mastrantonis, Greek Orthodox Archdiocese of America.
Prayer, Feasts, and Fasts, by the Ever-Memorable Metropolitan Philaret of New York.
On Fasting, by a Monk of the Orthodox Church.
Various Writings of Archbishop Averky of Blessed Memory. Translated and distributed on the Internet by the Brotherhood of St. Niphon.
Fasting in the Orthodox Church, by Archimandrite Akakios, Abbot of St. Gregory Palamas Monastery in Etna, CA (The Center for Traditionalist Orthodox Studies). This is the best summary of the Orthodox teaching on fasting. Read Chapter 3, "Fasting and Contemporary Orthodoxy in the Americas".
The Lenten Triodion (see above description in the "Orthopraxis & the Divine Services" section).
Fasting and Science by Constantine Cavarnos, (The Center for Traditionalist Orthodox Studies): this is the best short work I have read on the subject. Dr. Cavarnos knows this subject well. In his famous Anchored in God he writes (pp. 29-30):
Fasting takes into account both the quantity and the quality of food. The idea is to eat a smaller amount of food during a fasting day; to abstain from fats and oils, as these tend to fatten the body and thereby to arouse lust and make one physically and spiritually lazy; to abstain from meat, fish, and products of animal origin, as these tend to excite carnal desire; and also to abstain from mere delicacies, as the consumption of these is a form of self-indulgence. St. John Climacus (c. 525-605) says: "Satiety of food is a begetter of unchastity." He also says, "Let us cut down fatty and greasy foods that inflame carnal desire, and foods that sweeten and tickle the larynx" (The Ladder, Migne PG 88, 864, 865).
The practice of fasting is not regarded as an end in itself, as something having instrinsic value, but only as a means, as a necessary condition for the spiritual life. It belongs to the category of what the Eastern, Byzantine Fathers call "bodily virtues," among which are prostrations, standing, and vigils. Referring to these, St. John Damascene (c. 676-c. 754) says that they "are rather instruments for the virtues; they are necessary, in one practices them with humility and spiritual knowledge. For without them neither do the virtues of the soul come into being, but in themselves they are of no benefit, any more than plants without fruit" (Philokalia, 2, 17). And St. Gregory the Sinaite (1289-1360), speaking specifically of fasting, observes: "Constant fasting whithers lust and gives birth to self-restraint" (Philokalia, 2, 272); while Callistos and Ignatios Xanthopoulos remark: "Fasting and self-restraint are the first virtue, the mother, root, source and foundation of all good" (Philokalia, 2, 370).
Other food for thought, from the wise Nicephorus Theotokis:
"When we fast, we search the earth and sea up and down: the earth in order to collect seeds, produce, fruit, spices, and every other kind of growing edible; the sea to find shellfish, mollusks, snails, sea-urchins, and anything edible therein. We prepare dry foods, salted foods, pickled foods, and sweet foods, and from these ingredients we concoct many and motley dishes, seasoned with oil, wine, sweeteners, and spices. Then we fill the table even more than when we are eating meat. Moreover, since these foods stimulate the appetite, we eat and drink beyond moderation. And after that we imagine that we are fasting....
"And whoever taught those who fast in this way that such a variety and such quantities of food constitute a fast? Where did they read or hear that anyone who simply avoids meats or fish is fasting, even if he eats a great amount and different kinds of food? Fasting is one thing, great variety in food another; fasting is one thing, eating great amounts of food another." [Fasting and Science, 18-19]