I Had a Lower Body Lift 2 Weeks Ago, I Have Huge Amounts of Swelling (20lbs)! Is This Normal?

Yes, this can be "normal".  During and after your lower body lift surgery, your anesthesiologist and surgeon purposely give you lots of fluid.  After a 360 or circumferential lower body lift, your body's response is to hold onto fluid.  Once your body doesn't need all this excess fluid, your body will process the fluid and naturally get rid of it.  After a 360 lower body lift, this fluid retention can be for 2 to 3 weeks.  Just let your plastic surgeon know of your concerns, and let him or her examine you.  To minimize any more swelling, I would suggest compression from the rib cage to the toes and elevation of both of your legs .

A 20 lb weight gain after a body lift is a bit unusual. Yes, you do retian some fluid after surgery, and yes you are not as active as before surgery, but that sound like a lot. You should probably see your surgeon and evaluate this.