If you're looking for low-calorie, low-carb (but high nutrient) noodles, you can make various types of noodles out of zucchini (slice with a veggie peeler for 'lasagne', take those and cut into thinner pieces for 'fettuccini" or "spaghetti". Either leave raw and marinate in a bit of oil and salt, or steam VERY LIGHTLY. Otherwise they will get mushy).
Kelp noodles are another low-calorie, low-carb option.