Why do so many athletic, amazing pole dancers have large stomachs?

I really don't know how to ask this without sounding disrespectful, I don't mean any disrespect but it's something I've observed. I used to pole for about a year and now years later I'm getting back into it, and at both my old studio and my new studio I've noticed that many instructors or advanced students have large stomachs even though they aren't otherwise big. Kind of like a 3-4 month pregnant look, is this something that happens because of the muscles built? I've also noticed several that are super talented and advanced but still seem to have a lot of fat on their bodies and I'm shocked because wouldn't this intense of exercise make you lose weight? I always expected that they would be lean and have flat stomachs with six packs and it's a little surprising to me and makes me afraid of getting into it.