My ex used to ask me that all the time and I’d just say, shut up you sloppy ho.
But this query is not rhetorical and is more technical in nature.
I live at sea level in humidity and go to 7k feet and dry air each summer for a couple of weeks. I don’t stay long enough to fully acclimatize and I ride and climb daily up to 10 or 11k. I’m used to sucking wind and having no punch but along with this I’m constantly big bellied, like that sloppy ho I referred to earlier.
I’m guessing this is from belly breathing, my lungs expanding or having to work more or some such thing combined with some dehydration. It may also be that my body is stressed and grabs onto fluids and I puff up, I dunno. That’s where the ST brain trust come in. Any theories out there? Any other bloated idiots out there?
TIA
You completely neglected your diet in this post. I am inclined to say it is that, rather than any other thing you mentioned. Lay of the cupcakes 
Especially if you’re “puffing up”