Preheat your oven to 400°F (200°C) and prepare a baking sheet lined with parchment paper or a silicone baking mat.
Slice the chicken breast into bite-sized pieces for faster, even cooking.
In a shallow bowl, whisk the egg white. In another bowl, add the whole wheat panko bread crumbs.
Lightly coat the chicken pieces in the egg white then dredge evenly in the panko breadcrumbs for a crispy finish.
Place the breaded chicken pieces on the prepared baking sheet. Lightly spray or drizzle with olive oil.
Bake the chicken for about 15-18 minutes, flipping halfway through, until the chicken is cooked through and the coating is golden brown.
While the chicken is baking, prepare the sweet and sour sauce. In a small saucepan over medium heat, combine the pineapple juice, low sodium soy sauce, rice vinegar, honey, minced garlic, and diced red bell pepper.
Bring the mixture to a simmer and let it reduce slightly for about 3-4 minutes until it thickens just a bit.
Once the chicken is ready, remove from the oven and drizzle generously with the sweet and sour sauce.
Toss gently to coat the chicken pieces evenly and serve immediately.