Robin, I'm in a similar bandwagon.
I'm 5'3" and have a very light (but strong) bone structure. I was probably....the skinniest of kids in my class. Then after puberty, I started gaining weight way too fast. By the age of 22, I was 220 lbs. and for some reason, can't remember why, I went to see an endocrinologist.
Turns out I had PCOS, and the homrmonal imbalance was in part responsible for the weight gain.
I managed to make it down to 170 lbs. through diet, exercise and medication, but when I moved to the US, I spent 3 years as a live-in caretaker for my Grandmother, and it limited my movement so much that I gained 20 lbs. back.
Now I'm stuck in the 180's and trying to loose some of it.
/ Ze blog