When I was hospitalized for all of January and half of February one of the first things the hospital staff did was ask me about my known allerigies and dietary restrictions. I said that these are things I can't be given: caffeine, cinnamon, pineapple, grapes, olives, artificial sweteners, and acetaminophen.
The allergies meant decaf coffee only and no chocolate or soda. The acetaminophen alergy meant that I couldn't be given Tylenol - a go-to non-prescription painkiller - without experiencing side effects.
Playing bait-and-switch with what you're giving someone is dirty pool which should quite deservedly be punished very harshly.