I’ve gained 15 pounds after BBL

Liposuction in one area depletes fat cells in that area.  As a result, if a patient gains weight, the fat will be stored in other areas of the body preferentially.  Liposuction in an area reduces the number of cells in that area and the propensity for gain in the future.  Fat will be less likely to return to the places that have been liposuctioned. Fat cells can always increase in size with weight gain. Hence, the reason for weight maintenance.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

Hello and Great Question.  I appreciate the time you are spending researching this procedure.  My name is Dr. Matthew J. Nykiel.  I am a Board Certified Plastic Surgeon, a Fellowship Trained Cosmetic Surgeon, and a Butt Augmentation Specialist.
It is still very important that you maintain a healthy living and eating life style of surgery.  If you gain weight your weight will then go to your troubled area, i.e. your arms.  Getting back to a workout routine and healthy eating should help.
I hope that helps!  Best of Luck!
Matthew J. Nykiel, MD
#CoreAesthetic
Butt Augmentation Specialist
Liposuction Specialist
Board Certified Plastic Surgeon

You must still eat a healthy diet and exercise routine to maintain the result of the BBL. If you don't you will slowly gain weight. The areas that were not liposuctioned during your BBL such as the arms in your case tend to become your trouble areas over the areas that were liposuctioned. 

Hello,Thank you for sharing the information, it is a pleasure for me to answer your question.Following the recommendations of your surgeon is very important. The recovery takes about 3 weeks, and you can continue your normal activities, perform light exercises, then increase the routine without any problem.
 it is important to take a healthy diet, consult a nutritionist so you can take a diet plan, you can do exercises.
I hope this answer will help youMy best wishes for you...