Serving Size for Pasta with Meat Sauce?

If you go by the nutrition guides, a serving of pasta is 1/2 cup.

However, that is simply the amount that they have chosen to figure the values on. It doesn't mean that's all you can have for the meal. Remember that you can have 6-11 "servings" of bread and pasta per day! (A "serving" of bread is one slice; that doesn't mean you can't have two and make a sandwich!)

In my opinion 1 to 2 cups of pasta would be a reasonable amount for a main dish, depending on the eater's size and caloric needs. I would add about 2/3 cup of meat sauce.

For a side dish of noodles, I would stay in the 1/2 to 1 cup range. A one-cup serving of noodles is a decent, not stingy amount.
Granted, this is not scientific, just my opinion.