If that had happened to myself as explained, I would have immediately attended my lawyer to claim negligence against the Hospital of what "could" have happened had I followed the advices of food to be given to a pre known diabetic patient, as you state, no one expects a Hospital to kill one intentionally or unintentionally, the facts remain, clear to be offered such foods, a claim should be made by a legal person due to such frightening and concerning situations that seem to be taking place, continuing and no one doing a thing about, it, putting it forth to an internal department I doubt will do much it will be noted, and probably filed away the denouncement should be outside by a lawyer in my opinion, and if I was offered such foods, it is without doubt, I would take them all the way.
Mallorca