Sauté onions and celery in oil until translucent—do not brown. Add the garlic, herbs, salt, and pepper and sauté for roughly 2 minutes. Remove from pan and cool.
Add the ground turkey meat in a bowl, then put bran, ketchup, Worcestershire sauce, parsley and egg whites; mix well. Stir in cooled onion mixture and adjust seasonings.
Spray a 9-inch by 5-inch by 3-inch loaf pan with nonstick spray and fill the pan with the turkey mixture.
Bake the loaf at 350 degrees Fahrenheit to an internal temperature of 160 degrees Fahrenheit for about 1 hour and 20 minutes.
Let the meatloaf cool in the pan for 15 minutes. Remove from the pan, slice and serve.