Among the many different types of fasts that the Church has adopted over the centuries, one of the most severe fasts is the Black Fast.
The Black Fast was especially popular in medieval Europe, and is still practiced by some Christians today.
The Catholic Encyclopedia gives a brief description of this type of fast.
The Church encouraged this severe type of fast during Lent, as well as in preparation for any major event in a person's life.
Fasting rules were gradually relaxed over the centuries, but Eastern Christians still abide by a similar fast, though the particular rules varies by local tradition.
As with any fast, one should not engage in it without consulting a spiritual director and a medical doctor to ensure that you are getting the proper nutrition and not doing any severe harm to your body.
