I'm also a lifer who went to Disney last fall while trying to lose baby weight and here's my take on it. I didn't want to deprive myself as this was our 10th anniversary trip without the kids. So, yes, while I ate a little more (mostly at dinner) than I normally do at home, I walked 10 times more than I ever do at home! I ended up losing 2 pounds while at WDW- no doubt due to all the exercise! Go and have fun!