Some sleep apnea is caused by obesity. In my case you are correct. In Joe Rogan's case you are not.
I've been experimenting on my IBS for years and still haven't come to any firm conclusions. Sometimes I wonder if maybe it isn't a food intolerance at all -- for example, maybe some nights I sleep in my stomach and the pressure that causes shoves stomach acid through my duodenum counter-cycle to my digestion, and that stomach acid without bile salts or something similar is fucking things up. Just a hypothesis, hard one for me to test.