Bring a large pot of salted water to a boil. Add whole wheat penne pasta and cook according to package instructions until al dente, about 9-11 minutes. Drain and set aside.
While the pasta cooks, heat olive oil in a large non-stick skillet over medium heat.
Add the chicken breast pieces to the skillet. Season with salt and pepper. Cook for 5-7 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove chicken from skillet and set aside.
In the same skillet, add the chopped onion and sauté for 3 minutes until translucent.
Add minced garlic, diced zucchini, and diced red bell pepper to the skillet. Cook for 5 minutes, stirring occasionally, until vegetables are tender.
Pour in the diced tomatoes with their juices and the low sodium chicken broth. Stir in dried oregano, dried basil, and crushed red pepper flakes.
Bring the sauce to a simmer and cook for 5 minutes to allow flavors to meld and sauce to slightly thicken.
Return the cooked chicken to the skillet and stir to combine. Cook for an additional 2 minutes to heat through.
Add the cooked pasta to the skillet and toss everything together until well combined and heated through.
Adjust seasoning with salt and freshly ground black pepper to taste.
Remove from heat and sprinkle chopped fresh parsley over the pasta before serving.