Personally, I haven't had much trouble with people cooking when there's other food handy. But oh, the juice bar! I put a professional-grade bar in my sims' house. I threw a party. The family mixologist made Party drinks and Energy drinks - a couple trays of each, sitting right out in the open. Plenty of juice for everyone!
Every dog-gone guest at the party then proceeded to make at least one tray of quick drinks. Adding insult to injury, nobody actually drank anything - I had to clean up about 7 trays of quick drinks when all was said and done.
I've noticed my family members doing the same kind of thing sometimes - it seems like if the mixologist is working, and only if the mixologist is working, everyone else is likely to start trying to make quick drinks. Otherwise they leave the bar alone entirely.