Provided that you are otherwise healthy, I do not think that you need to lose additional weight before your Brazilian Butt Lift. Good luck!
Losing weight before a bbl is better than losing it afterwards because your butt may shrink as well with weight loss.
For patients with loose skin of the tummy I don't like liposuction. Liposuction for these patients will not result in the nicest outcome. The skin will still be loose and the body shape won't change much. I recommend tummy tucks for those patients. A tummy tuck allows tightening of the muscles and removal of the excess skin. That procedure alone will help give you curves. Part of creating curves is adding volume to the buttocks and hips but also making the waistline smaller. Based on the pictures I like the idea of a tummy tuck. The great thing is that a BBL can be done at the same time. Liposuction of the back, waist, lower tummy (the tissue to be removed with the tummy tuck) and the inner thighs can all be used to get enough fat to make a nice change to the buttocks. You didn't show pictures of your thighs but based on your measurements I imagine that there is a little there that could be used. As always consult with a board-certified plastic surgeon with experience with the procedure you're thinking about. Best of luck.
Thank you for your question. It is possible at this time to proceed with your plans for a BBL. There are also a couple of reasons why it might be good to lose a bit more weight first. If you lose enough weight to get your body mass index below 30, you reduce your risks of a wound healing problem and of blood clots after surgery. It will also help you to lose some of the intra-abdominal fat around your organs that make your tummy stick out. Overall, you would probably get a better result with a bi more weight loss. You may also have to consider a tummy tuck to tighten the skin and muscle of the tummy area to give you a better chance at getting an hour glass figure with fuller hips and buttocks. Take a look at the link below for additional information. Best wishes!