I have a Dom friend in real life - totally ripped, completely tatted up, as fit as can be - who has an obsession with bellies. Mind you, his sub is thin and perfect, but he has a few play partners who are chubby or overweight with wonderful bellies. He's a sensitive guy, though. I've never seen him play in a way that degrades them over the size of their stomachs ever, and I can't imagine him being into that. It's more like a belly worship.
I could see some beefy trainer who has a love hate relationship with fat (it's his enemy and yet he's drawn to it) having fun with an overweight submissive play partner by shaming her for all of her excessive fluff, and knowing EXACTLY how to push those buttons because the majority of his clients in the gym are self conscious women.
(Me personally, I don't even like my Daddy touching my tummy. The only thing that runs through my head is, "stop touching my fat!"... but I've been letting him lately. I realized he just wants to touch me. And I like being touched.)