Fat actually satiates you more than almost anything else, so I suspect your culprit is sugar, not fat. If you cooked those veggies in some butter or olive oil, I would bet you’d get full faster.
Possibly, I think I recall reading about the fat+sugar being ultra nasty because your brain never wants to stop this mouth sensation. That said, I don't feel the same when eating fatty stuff, it's more nausea than what I feel with veggies.
