I'm totally good with the pleasures of the stomach, but the thrust of many of these quotes makes the belly appear to be more important than any other part of the body
Well, it might be.
I was just thinking about this the other day. I was asking myself, "If I had to take a basic math test, would I score better with a stomach virus? Or with heartbreak?" I'm not sure if the answer would be the same for everyone, but I decided that I could manage with heartbreak (or turmoil better). With a stomach virus, I'd feel incapable of mustering the focus to apply critical thought. With heartbreak, through extreme focus, I can make the numbers make sense. I was thinking back to when I took the SATs, and I do well on those kind of tests, and I was a psychiatric mess when I took it. But when, back in the day, I'd suffer a hangover, I could barely focus on my name, let alone algebra.
I'm also thinking in terms of the value of digestive processes versus intellectual faculties for growing organisms. Depressive thoughts can mislead you, but a stomach ache is as honest as your eyes. It will never give you severe pain without a concerning, physical cause. Sometimes the mind hypes itself up. At that, we have the Epicurean Doctrine about the infinite desires of the mind, because, without a sharp intellect, the mind doesn't self-regulate. But the stomach won't let you trick yourself. You can't just shove something down that makes you sick the way you can repress bad memories ... well, maybe to a degree, but I think you see what I mean, in general.