Does a Brazilian butt lift address saggy skin on the butt and in the upper thighs front and back? (photos)

Do BBL's tighten the skin? I have saggy thighs and butt from a 50 lb weightloss and i need a butt again. But what about he sagging skin? Do you trim it under the cheeks as part of the buttlift if necessary? It seems that a bbl automatically includes lipo but, is it up to the patient where the doctor harvests the fat? Can a patient request it be evenly taken all over if they need it in order to have a great asthetic outcome? I wamt a bbl but need to know if it will lift my thighs at all..thank you!!