Combine turkey, egg whites, bread crumbs, poultry seasoning, garlic, and salt in a medium bowl. Shape about 1/4 c each of turkey mixture into balls; arrange on a cookie sheet coated with cooking spray. Bake until turkey is no longer pink inside, about 20 minutes.
Meanwhile, cook spaghetti according to package instructions, excluding oil and salt; drain. Combine cooked spaghetti with sauce and warm over medium heat. Remove from heat, add meatballs and toss to coat. Yields about 3/4 heaping cup of spaghetti and 2 meatballs per serving.