How much fat will remain from a 2000 cc fat transfer to each check?

 About 50% of the fat that is transferred lives and becomes a part of you.  This will hold stable as long as there is no weight fluctuation. The results immediately following surgery will be the largest due to swelling and lack of fat resorption.  The buttocks will continue to decrease in size for the first few weeks.   I have observed that between 4 and 6 weeks the buttocks tend to stabilize in volume.  Usually by 3 months, the swelling is minimal and totally resolved by 6 months.  
Kenneth Hughes, MD, ABPS Board Certified Plastic Surgeon
Los Angeles, CA

Dear lilyhernandez83,
in most cases 30-50% of transferred fat will be lost. I instruct my patients not to sit for 2 solid weeks. We provide them a specialized pillow that our patients can sit on during that time. They can sleep on their stomachs or sides. 
Fat viability depends a lot of surgeon technique. The fat has to be placed back into the buttocks as soon as possible so that it has a greater chance of survival. It has to be placed carefully so that not too much fat is placed in only one area.
Daniel Barrett, MD

Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Hello dear!!
Thanks for the question and provided information as well.
After a BBL, only about 70% of the transferred fat cells will survive, so it is normal to see a minor reduction in your buttocks. If you have any concerns, I suggest you to follow up close with your plastic surgeon.
Good luck :)