Wish I could tell you what to do, but I have a similar problem (except that I'm starting at a higher weight). My weight tends to peak in the spring, then drop gradually all summer, then starts going up again, oh, about now. Of course, eating healthier and exercising more in the summer may have something to do with this I'm going to do my best to continue healthier habits through the winter. I even - gasp! - joined a fitness club. We'll see.