Mowgli's not exactly fat, but he has a lot of muscle and his fur is quite short, so he weighs a lot more than you'd expect. I thought that he'd get pudgier after being neutered. It seems as though his energy is going in to growing, though.
My suspicion is that your Bengal has A LOT of Egyptian Mau in him. Egyptian Mau's suffer from getting a little fat, if neutered as they they love food. Egyptian Maus are very lean cats, with low body fat and are deceptively heavy. My own Egyptian Mau adheres to this quality.
Looking at your Bengal, he looks a spitting image of one of the Bronze Egyptian Maus which was offered to me, when I was looking to buy one.