It's almost impossible to say what size you'll be able to fit into or what weight you would be too thin at until you actually get there. Everyone comes in all different shapes and sizes and we all carry our weight differently based on our genetics so it's really one of those things that you'll just have to "stay tuned" to find out!
To give you somewhat of a guide (but your results could be completely different) my cousin is 5'7 or 5'8 and has a large frame and an athletic build. I believe she's a size 12 in jeans but she has a flat stomach and is toned all over. I'm pretty sure she's around 150-160 lbs. She has an awesome body and doesnt look like she has to drop a single pound. I'm 5'4 and when I was a size 12, I looked chunky. You might find that once you reach a size 12 or even 14, considering your height you may realize that you don't have to lose anymore.
I found a healthy weight chart and according to the chart this is what it says for females your height. It can still vary from person to person, but you can use this as a general guide. For female's 5'11 with a small frame a healthy weight would be between 135-148. For a medium frame 145-159 and a large frame 155-176.
oh and another thing.. i am wondering how i will look at 150-160 since i am super ( freakishly) tall.. do you think i will look too thin?
Before I got pregnant.. my weight was evenly distributed.. ( take a look at my pictures before i was pregnant and after).. and now i have a lot of extra belly weight and i hate it! ive always been bigger but it wasnt noticeably because i was evenly distributed.. ugh..
I agree with wonko. I generally carry most of my weight in my waist area, but I am heavy throughout my body. Just take me as an example. I say i wear a size 18 or 20 in jeans and work pants and you weigh less then me and wear a size 18 too. Like wonko said, I don't think I could ever wear a size 2 I'm looking to wear a size 12 (still plus size, but I feel it would be best for my body). I also have alot of curves. Like my boyfriend told me, no matter how much I weigh my butt will always be round and sticking out LOL. It's true, thats how my body is shaped my back arches in and my butt sticks out.
I'm 5'9" and have a large frame. I was once much thinner when I was younger, too thin in fact. Everyone is different, but I know that my body type can't get down to tiny sizes. More petite women change sizes faster (with less weight loss) than taller women.
Do you carry your weight evenly? I do, I don't put it all on in one place. That also makes it slower to change size. If, for example, you carry a lot of your weight on your waste, you may drop through sizes faster than some one whose weight is more evenly distributed.
I've observed that sizes run bigger now than they were several years ago. So I don't know if the size I was when I was underweight would translate to today's sizes.
Anyway, you don't know what you body would look like in that dress. It may look great on the hanger, but who knows if it would work with your figure if you did get down to that size? Perhaps you can set up some short-term weight loss goals (1 or 2 months?) and see how it goes, and re-evaluate what type of dresses and sizes might work best for you?
Well, not sure if this helps...but for every 15lbs or so you lose a size. I've lost 60lbs and I now wear a size 18 or 20 from a size 26. I'm also alot shorter then you (5'3") so I carry my weight different.
ohh and i am 5'11.. i dunno if that helps out or not