I feel a BBW is just someone who is not their ideal weight. I think I could be considered BBW, but I am tall and carry more weight as compared to someone who is the same weight and much shorter. In fact when I do give in adn tell my weight most people don't believe me.
My favorite story is when I had a stress fracture in my left leg. Back when I used to run (yes Spoo I used to run

), I thought i had a shin splint. The doctor checked me out and when he weighed me he kept looking around me, he said he thought I must have had my hand on the table or something because there is no way I could weight that much.
I like to think it is the overall heft of my oversized brain that adds on the pounds.