It is clear that the fast is designed to prepare us both physically and spiritually for the coming of the Savior at Christmas. We are asked to abstain from meat and dairy products, eggs and oil, just as we do during the Great Fast, but the rules are a bit less strict. We may eat fish and are allowed oil and wine on Tuesdays, Thursdays and weekends, and on feast days such as the Presentation of the Theotokos and St. Nicholas day.
Many of us haven't given the Nativity Fast our full attention over the years, partly because we haven't been aware it existed in certain regions. Growing up, I didn't even realize it was a "thing"!
Sadly, among my community here it has fallen into the category of "things the old people used to do", that is...until some of us decided to revive it. What a wonderful tool the practice of fasting an be! How well it aids us in growing closer to God! If only people would try it! That said, I challenge those of you who are new to the idea to come along with us and take a second look at fasting with the Church this season. Start slowly. Add on from year to year, one step at a time, and grow in your fasting practice. Its a good idea to begin together, as a family, building community with like-minded Christians who are striving right along with you." --- read Lynn's entire post at byzimom.com