I don't even need to answer this question, because my buddy Andy sent me an e-mail that I think answered it better than I would. I haven't even asked his permission to include this quote so I guess you better be careful what you e-mail to me. Ha ha! Here it is:
"Bro, its a good thing you shared about [your fast].
I find it funny (ironic?) how the church notes Jesus saying not to make a show of your fasting but then we forget in the same passage that he also said to not prayer in public but in a closet yet we don’t ream people for public prayers. I would say we have way more people who have showy prayers than proud fasters. Or we note in the story in Luke 18 of the Pharisee bragging about his two-a-week fasting habit but he also spoke of his tithing and we have tithing sermons.
I think the passage in Mark 2:18-20 seems to say that fasting should be the norm for followers of Jesus after He leaves. True fasting is another mark of desperate prayer."
So long as you're not bragging or looking for sympathy, I think it's okay to talk about this stuff. I mean, we know somehow that Jesus fasted for 40 days. He must have told someone. Honestly, it's pretty hard to hide a fast that goes more than a day. Having said that, I generally prefer not to talk about my fasts or let anyone other than absolutely necessary know I am fasting.
My kids--and this is hilarious--still haven't caught on that I'm not eating anything (It's day five of the fast!). They don't notice. Suddenly it makes sense that they are constantly asking me to get them milk, refill their plate, change their forks out and so on when I just sat down to eat. They think I ate already.