Gained 12lbs during the Holidays!

I have been using mfp for a year now and since I started, I have lost 40lbs! But this holiday season I went from 199lbs to 212 or 212. I am back dieting and exercising really hard right now, but I am curious to know how much is water gain and how much is fat? I'm thinking that within a week or so, the scale will show me weighing 10lbs lighter.

What do you guys think?

Thanks!