plateau-ing weight??

mrf2990

I have been working since August 2012 to drop some major weight. Recently, I've been weighing in 20-25 lbs down, but I can't seem to loose more. It's been like this for about a month and I haven't even really changed my habits since I started loosing weight. I think I might be more active, but that's it. Any idea why I can't pass this plateau?!