Preheat oven to 350°.
Heat oil in a large nonstick skillet over medium-high heat. Add onion, bell pepper, and garlic; sauté 3 minutes. Cool.
Combine onion mixture, cheese, and next 6 ingredients in a large bowl; tossing to moisten bread. Crumble turkey over onion mixture; stir just until blended.
Pack meat mixture into an 8 x 4-inch loaf pan coated with cooking spray. Bake at 350° for 35 minutes. Combine 1/2 cup ketchup, brown sugar, and mustard in a small bowl; stir well.
Spread ketchup mixture over meat loaf and bake an additional 5 minutes. Let stand 10 minutes.
Remove meat loaf from pan. Cut into 10 slices.