Meanwhile, in large nonstick skillet over medium heat, heat oil. Add onion, bell pepper and garlic and cook, stirring often, until softened, about 5 to 6 minutes. Turn out of skillet into bowl with potatoes. Add beef, ½ cup of the ketchup, bread crumbs, egg whites, mustard, Worcestershire sauce, salt and pepper and mix well. On the prepared pan, shape the meat mixture into a loaf about 10 inches long, 5 inches tall and 5 inches wide. Spread top with remaining ½ cup ketchup.