Will Weight Loss After Breast Implants Affect Cup Size?

Weght loss and the effect on breast size after implantation all depend on the fat content of the breast, the percentage of breast tissue relative to the implant as well as your own genetic tendencies for regional weight loss. IF you were an A cup before, it is not likely that you will sustain any substantial amount of breast tissue involution. However, I, anectdotally have one pateint that visbly devlops (uncovers) breast rippling when she loses 5 pounds (she is 5'7" and 125lbs)

Thank you for the question. Although weight loss will not have a direct effect on your breast implants,  significant weight loss may affect the appearance of your breasts in general. It is difficult to predict how a specific young lady's breasts will change with weight loss; how the breasts were affected historically with weight loss may be  the best indication how you will do.
Generally speaking, significant weight loss can lead to some change in breast tissue (and/or nipple/areola) position;  this “sagging” is called breast ptosis medically.
Sometimes, patients who lose weight will have a smaller amount of breast/soft tissue coverage overlying the breast implants; this change in breast anatomy may lead to a greater degree of breast implant palpability and/or rippling.  In these cases, the breasts may also appear smaller.
Therefore, generally speaking, it is in patient's best interest to achieve a long-term stable weight prior to undergoing elective breast surgery.
I hope this, and the attached link, help.

If your breasts were at all fatty, then it is possible that as you lose weight, your breast will shrink a bit.

When a Plastic surgeon performs a Breast Augmentation he assumes that your body will remain in THAT condition for the foreseeable future. For this reason, we do not like to operate on women who are planning on getting pregnant or lose weight.

A key factor in how natural an augmented breast looks is picking an implant which is hidden by and covered by each woman's breast tissue. Obviously, the smaller the breast, the less available breast tissue, the smaller the implants that would look attractive in that woman. Since ALL implant shells have ripples (more with saline than silicone filled implants), the more soft tissues that can be placed on the implant to hide the ripples, the better. For this reason, in smaller women and those with little coverage, silicone filled implants may be better.

Breast implants placed under the muscle are covered by both the pectoralis major muscle (on their upper third) and the breast gland while implants placed under the breast do not have this dual coverage. If you lose weight from your breast, you may reveal more of your implants and have a more ripply look of your breasts.