How much muscle will I really loose?

I know they say when you fast you loose muscle....I was wondering how much muscle I really would loose if I do a 14 day Master-Cleanse fast? I just started training with weights only 3 weeks into it....I work with a trainer for 30 minutes 3 times a week and he does make me lift heavy weights ( well heavy for me). I've told him I"m fasting and if I can handle weight training I;m going to stick with it through my fast...but I was wondering how much muscle does one acutally loose when they fast for 14 days and will weight training help me to loose less?
I'd really appreciate any responses! Tweet