1. Heat oven to 350 degrees . Place squash, cornmeal, milk and soy sauce in a large bowl and stir well. Let mixture stand for 5 minutes to allow cornmeal to soak up some of the liquid. Stir in turkey, egg and garlic. Mix well.
2. Coat an 8 x 41/2 x 3-inch loaf pan with nonstick cooking spray. Add turkey mixture to pan, smoothing surface. Top with ketchup or barbecue sauce.
3. Bake at 350 degrees for 45 to 50 minutes, until meatloaf registers 165 degrees on an instant-read thermometer. Cover with foil and let rest 5 minutes before slicing.