Thoughts on fasting from the eastern church. (The sound quality is scratchy, but it is subtitled. 6 minutes.)
Saint John Chrysostom
For let not the mouth only fast, but also the eye, and ear, and the feet, and the hands, and all the members of our bodies. Let the hands fast, by being pure from rapine and avarice. Let the feet fast, but ceasing from running to the unlawful spectacles. Let the eyes fast, being taught never to fix themselves rudely upon handsome countenances, or to busy themselves with strange beauties. For looking is the food of the eyes, but if this be such as is unlawful or forbidden, it mars the fast; and upsets the whole safety of the soul; but if it be lawful and safe, it adorns fasting.
~ St. John Chrysostom (Homily III, paragraph 8, Ascetic Treatises)
St. Basil the Great
Beware of limiting the good of fasting to mere abstinence from meats. Real fasting is alienation from evil. “Loose the bands of wickedness.” Forgive your neighbor the mischief he has done you. Forgive him his trespasses against you.
St. Basil On Fasting (pdf)