Can you continue a keto diet after a BBL? Or can I lose weight after a BBL without losing any volume in my butt?

Once the result is there by 3 months it does change as your fat changes. So if you gain weight it gets bigger if you lose weight it does get smaller. there is no particular diet that would change that.Best Regards,Dr Michael Gartner

hello thank you for your question and provided information as well..based on the exposed case the ideal would be that no, because it is fat what we graft, that is why if you continue strong diet the deposit of fat that this in the body does not matter where it will go.Diets are recommended after 4 months and no extreme eating normal.

Hi. If you lose weight the volume will decrease, remember you have fat cells (adyposites) that enlarge or diminish depending on your fat deposits. They will continue their behaviour wherever they are transfered.International Member of the American Society of Plastic Surgeons (ASPS)
Member of the International Society of Aesthetic Plastic Surgery (ISAPS)

Any Liposuction of a BBL doesn’t change the way fat cells on the outside of your body change. If you gain weight they get larger and store more fat and if you lose weight they get smaller and will shrink and lose their fat. 

A BBL works by transferring the fat cells to the buttock.  If somebody looses weight after a BBL, fat cells everywhere in the body will shrink.  Thus the fat distribution will reflex the changes after the BBL.  So the answer is yes, you will lose volume, but the volume loss should be everywhere you have fat and not only in the buttock.
I am unaware of any evidence that shows that a ketogenic diet would alter fat distribution differently than other diets of similar caloric intake.  Best of luck and for specific advice please seek an in-person consultation.