Sounds cool, but it might make non-healthy foods less valuable if no one would want to buy them. Maybe just random upset stomach from eating any type of food?
This could be another food related illness. "Vegeta says: Ouch, this food is making my teeth hurt! Will you buy me some Fang Paste?"
The Enchanted Springs could have a tiny chance of making your pet ill too: "Kakarot says: Brr, that water was too cold! I think I'm coming down with something. Can you get me some Jumbo Tissues?"
or
"Blah, that water was muddy! I think I need some Pink Soap now"
I'll try to think of more.