"Though they are both outrageously rich pasta sauces, carbonara and Alfredo are distinctly different. The base for Alfredo is cream and Parmigiano-Reggiano. The base for carbonara includes onions, bacon or pancetta (originally it was guanciale -- cured pigs' cheeks), egg yolks and Parmigiano- Reggiano or Pecorino Romano. At almost 1,000 calories per serving, this dish was ripe for a makeover."
-- Rocco DiSpirito, "Now Eat This"