Preheat oven to 350°.
Place bread in a food processor; pulse 5 times or until crumbly. Sprinkle crumbs on a baking sheet; bake at 350° for 5 minutes or until golden.
Cook pasta according to package directions, omitting salt and fat.
While pasta is cooking, heat 1 teaspoon oil in a large nonstick skillet over medium heat. Add garlic; sauté 1 minute. Stir in breadcrumbs; cook 3 minutes. Remove from pan, and stir in walnuts, parsley, and 1/2 teaspoon salt; set aside.
Add 1 teaspoon oil to pan and place over medium heat. Stir in zucchini; sauté 4 minutes. Stir in remaining 1/2 teaspoon salt and pepper; keep warm.
Combine pasta, remaining 1 teaspoon oil, zucchini, and breadcrumb mixture; toss gently. Sprinkle with Parmesan cheese. Serve immediately.