In a small bowl, combine 1/4-cup of the vegetable or tomato juice and the catsup. Set aside.
Combine all other ingredients and mix well. Form into a loaf and place in a 1-quart loaf pan.
Bake in 350°F oven for 50-55 minutes or until center of meat loaf reaches 160°F on an instant read thermometer. Top with reserved catsup mixture during last 5 minutes of cooking.
Frozen spinach that has been thawed and squeezed dry can be substituted for the fresh spinach.
Gentle handling when mixing the ground beef with the other ingredients will ensure a moist, tender meatloaf.