Do not get breast implants to prevent fat or volume loss. Get them if you need more volume. If your breasts are sagging, then you may need a tune up on your breast lift....not an implant.
The implant may prevent the decrease in size from being as dramatic as it might be with a significant weight loss but it will do nothing in terms of helping slow or avoid the sagging in any way
After a reduction which means you also had a lift it is not very common to ask for implants which will make you larger, but in some cases it may replace lost volume should weight loss make it necessary.
Patient's who have needed a breast reduction generally have a loss of skin elasticity that can be expected to lead to some sagging as you lose weight. IF this occurs, you could consider fat grafting or placement of a small to modest sized implant to restore some volume. Too large an implant will cause more stretching and thinning of your tissue and should be avoided IMO. Also remember that your breasts may still be growing at age 19 so discuss all options with your plastic surgeon.
Jon A Perlman M.D., FACS
Certified, American Board of Plastic Surgery
Member American Society for Aesthetic Plastic Surgery
ABC-TV Extreme Makeover Plastic Surgeon
Beverly Hills, California
The decision of improving breast contour after weight loss and sagging breasts depends on the position of the lower pole and nipple as it relates to the crease under your breasts. If it is below, then a breast lift, and possibly an implant, would be appropriate.
Getting breast implants after breast reduction is counterintuitive especially if you are a DD now. Remember that you got your breast reduction to take the weight off of your breasts and now you are considering adding weight back on. I would recommend that you lose your weight first and see how your breasts look first.