N.S.
I have one of my own that's definitely not low in fat, but the kids like it.
2 cups of cubed Velveeta
3/4 cup whole milk or half and half
4 tablespoons of butter/margarine (sliced in small pats)
Boil 6 cups of water. Once boiling add 1 1/2 cups of small elbow macaroni or tiny shells. Boil until al dente for about 7 to 9 minutes.
While bringing the pasta water to a boil, in a separate saucepan, melt Velveeta, 1/2 cup of milk, and butter on medium low heat. Slowly continue to pour in the remaining milk and continue stirring. Use a double-boiler pan if you have one for the best results. If you don't have one, and the sauce begins to scald, turn down the heat to the lowest setting and continue to keep stirring until the cheese and milk are blended and creamy. It'll take about 15 to 20 minutes to get the sauce to a creamy consistency. The key to success is a slow melt and continuous stirring.
Drain pasta, and return to pot. Slowly pour in cheese sauce and stir entire pan of sauce into the pasta, mixing it throughly until blended. Top servings with pepper to taste and shredded or grated parmesean cheese. Enjoy.