TBF, an obese woman who gets back down to human size is going to need breast reconstruction surgery.  Your breasts get stretched out by the fat so when you lose it, they look like deflated balloons. I suspect that’s not what she’s talking about.  And anyway, how can a few pounds of breast tissue be a problem and fifty or a hundred pounds of extra adipose be fine?  I don’t get these girls who whine about their boobs hurting their back.  Like, I’ve got big boobs and a normal BMI (and can therefore never find bras at the store), but they don’t hurt my back.