I was as skinny as hell when I was first diagnosed, as:
no insulin = no break down of carbs = break down fat instead (producing nasty ketones as a side-effect).
So I guess this is what’ll be happening if your BG is high all the time.
Personally, I’ve gone for fat and happy! I’m not exactly porky but I could probably shed a pound or two and try to do that by exercising (sometimes) by going out on my bike. I find exercise does actually make me feel better and actually helps my control for whatever reason.