how much weight loss will cause your breasts to sag

Hello. I'm 37 year old female and I would like to find out few information and advices about some aspects of weight loss. You see, for always I've had problems with keeping my body weight in some normal limits. The problem was definitely just in me because no one in my family was overweight and it wasn’t anything inherited.
So, I've decided to lose some weight but I've seen some pictures of women who lost weight and still look terrible.
Their breasts are the worst thing on them because they sag and look devastating. So, I was wondering could anyone tell me how much weight loss will cause my breasts to sag.
Thanks!

Hello. I have read your post and it has made me thinking because the question is really interesting. So, I have read several articles about it and listen now what I have found out.
There is no exact information about how much weight loss will cause you breast sagging because, in fact, that is almost unavoidable.
Aging, pregnancy, breastfeeding and -of course- weight loss all take their toll. But, I have read some great stuff about one operation called mastoplexy. It is primary operation of breast lifting but mastopexy is often combined with augmentation because breast volume is also often a problem. During mastopexy bothe-the nipple and areola are repositioned to a higher position and excess skin is removed underneath the breast. The operation is short and not so expensive. The efficacy is almost absolute-100%.