I posted about the exact same thing and got some wonderful advice.
First, try it out for a week or so...just to see how your body handles it.
Second, after trying it out, take away 300 calories from it and see how it goes.
Well..I fell off the wagon half way through and quit logging my calories..but I did stay the same weight. So now I'm changing it up. I walked half a mile yesterday and .7 of a mile as of right now but I also have some walking to do later today as well.
Everyone reacts differently....so see what your body responds to and go from there