Although you raised very interesting issues, Colwyn, it takes a rather long projectile to link Roman vomitoriums to the onset of the Dark Ages. Historians attribute the Dark Ages to other causes like plagues that killed up to two thirds of the population in some areas and the difficulty of continually extending Roman technology and control over everyone else's territory. Even consubstantiation versus transubstantiation played a role. Hundreds of thousands of sincere Christians killed other sincere Christians and the Holy Roman Empire was divided into east and west over arguments about whether someone eating the bread was actually munching on Jesus or just having a symbolic chew on him.