| The answer is... complicated: - Using butter for pasta is something that is typically reserved for people with upset stomach (understand diarrhea). It's not scientific at all, but just something that is commonly done. - Fettucine Alfredo[1] is a real italian dish invented in Rome. It's made with butter and cheese. It was originally popular in the touristy areas, targeting foreigners, but over time I notice it slowly appearing in "real" restaurants. - "Pasta Fresca" (tagliatelle, raviolis, tortellinis, etc) is often served with butter-based sauces (like a lot of the traditional northern cuisine). A simplistic way to think about it is that butter is a rich luxurious ingredient used in the North, whereas the South is more likely to use Olive oil. Note that other fats can be used, it's not just olive oil:
- Carbonara / Alla Gricia will use the animal fat from the _guanciale_ (the cured pig meat) and avoid using any oil or butter
- Cacio e pepe will use neither and use the cheese itself as fat for the sauce. It's a simple pasta, but it's difficult to get right, since parmesan/pecorino are diffcult to emulsify.
[1]: https://en.wikipedia.org/wiki/Fettuccine_Alfredo |