In general, patients should be at a stable weight prior to surgery. Gaining weight will likely only lead to disappointment after surgery as most patients cannot maintain the weight and results. There are a lot of women who can get nice results despite thinking that there is not enough fat. The thinner patient requires an expert at liposuction to remove as much fat as possible while leaving the skin smooth. I have liposuctioned models and thin patients with good results. Fat can be taken from many different areas of the body including abdomen, sides, bra rolls, thighs, arms, underarms, flanks, lower back, upper back. You have to consider not only which areas will have perhaps the best fat, but also you have to consider which donor sites will have the fewest problems afterward with the liposuction. In general, the abdomen and thighs are preferred, but, if those sites are not available, other areas can be used. Creative liposuction with fat transfer to the hips can make hips appear lifted, and rounder. If the waist was smaller at one time, the waist can likely be reduced to those same measurements or smaller provided the muscular and fascial integrity has remained the same. Consult via Skype or in-person with a board certified PS who performs hundreds of BBLs annually with favorable patient reviews and photos showing significant results on his/her website.