In a large pot of salted water boil pasta shells until al dente. Drain well and rinse.
Preheat oven to 375 degrees F (175 degrees C).
In medium bowl, combine spinach, mozzarella cheese, cottage cheese, egg white, parmesan cheese, nutmeg, and Italian seasoning until blended.
Fill each pasta shell with a heaping tablespoon of spinach mixture. Pour 1 cup spaghetti sauce into a 8x12 inch baking dish, spread evenly. Place shells in pan. Spoon remaining spaghetti sauce over shells. Cover with aluminum foil and bake for 30 to 40 minutes, or until shells are heated through.
