This has the potential to be a good recipe. The non fat and low fat ingredients spoil it and ruin the flavor. Studies have shown that it is not the fat that is bad for us, it is the saturated fat and carbs that get us. If you read the ingredients on low fat and non fat products, I'm sure you would agree that they are not so healthy.
This was a very good one-dish meal! I used a store-bought can of spaghetti sauce but think this would be better jazzed up with some peppers and spices. I bbq'd the chicken for added flavour. I had a little bit of sticking on my glass pan so I would suggest either spraying with cooking spray or spreading a small amount of sauce around the pan before adding the shells. To get supper on the table quickly, I did all the prep the night before and stored covered in the fridge overnight.