What is the minimum BMI for a breast fat transfer? Or is it judged on a case by case basis? (photos)

I hate to tell you but the surgeons you saw were right. It is not that you do not have any fat to transfer, but a matter of how fat transfer works. Lets just say that you are a B cup and want to restore fullness up to a C cup, for example. One cup size of volume is about 150-200 cc, for both breasts, you are going to need to retain a total of 300-400 cc of volume. Take into account that breast fat transfer long term maybe retains 50% of the volume injected, so now you are needing 600-800 cc of fat. Now take into account that if the fat is cleaned and processed prior to injection for maximum purity and retention, about 30% of the fat removed will not be suitable for injection, now you are going to need about 800-1000 cc of fat for a reasonable transfer. So now maybe you have a better understanding of why they felt you were not a good candidate. You have two options, if you really want the result no matter what, then consider an implant. If you are 100% against implants, then you can proceed with fat transfer but understand that the chance of a contour deformity in the donor sites is significant and also you have to be accepting of the possibility that at 3-6 months from surgery, you notice no difference in the overall volume of the breasts (not likely, but possible given the unpredictability of fat).
Hope this helps!
Dallas Buchanan, MD
VIVIFY plastic surgery
Tampa, FL

BMI is not the determining factor for breast fat grafting.
In your case you have sufficient extra fat in your abdomen and waist
I also add PRF which is extracted from your blood ,to the fat graft

Unless you have some usable fat in your abdomen, you do not have enough fat for your breasts. You need implants for your best look.