I really feel like your character getting sick happens way too often and lasts way too long. It really kills the pace and fun of the game whan all you can do is sit and wait for it to go away, or mash the serve button until it goes through.
IMO, there should be some indication of what exactly makes them sick, it almost seems random. I know some foods seem to really make them sick easily, but I'm not really sure why they get sick otherwise. Seems like maybe it's a chance based on how big a certain food is compared to your stomach capacity, IDK.
Either way, I skipped the dodgy mechanic entirely by mass-purchasing cheap, small (and small-ish) foods, then stockpiling certain badges to make the small foods more useful, then I use an autoclicker on my mouse to eat thousands of them individually, my character never gets sick anymore, and I get to chuckle at the mints' description about getting immobile from mints.
Idea to make the mechanic a little more clear: a "health" stat for all foods. Eating too many unhealthy foods runs a higher risk of making the character sick, but eating healthy foods is worse for the $/cal side of things, and slows down gameplay. Maybe healthy food even takes longer to digest?
Kind of like an active vs passive choice?