Not sure what's in Burger King onion rings, but man do they make me gassy. But no other types of onion rings do that. I had them at lunch years ago when I had an office job. By 3:00 PM I was a farting machine. My farts didn't smell like typical farts though, but rather more like cooked food. It was so weird. Then a colleague entered the office. He said, "what's cooking? Smells good in here." There I was killing myself laughing. I couldn't tell him it was my farts. LOL