I have lost a lot of weight. I started out at a 46C.  Now, close to 100 lbs lost, I'm 38DD.  I think they helped.  I also kept some of the leg/but fat and that has helped with my shape.  However, look at the body shape of your nearest female relatives: if they are hour glass types, start HRT. The mobs will help breast development.   It they are Ovoid, maybe keep losing a little weight.
Jen