Low Calorie Meal Prep Spaghetti Squash & Marinara Chicken – Simple, Satisfying, and Weeknight-Friendly

Looking for a comforting pasta-style meal that won’t blow your calories for the day? This spaghetti squash and marinara chicken hits all the right notes—savory, saucy, and surprisingly filling. It’s easy to prep, stores well, and fits right into a busy schedule.

You get real flavor, real satisfaction, and none of the heavy crash that comes with traditional pasta. If you’re trying to eat lighter without feeling deprived, this is the kind of meal that makes it feel effortless.

Low Calorie Meal Prep Spaghetti Squash & Marinara Chicken - Simple, Satisfying, and Weeknight-Friendly

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings: 4 servings

Ingredients Method

Ingredients

  

• 1 large spaghetti squash (about 3–4 pounds)
• 1–1.25 pounds boneless, skinless chicken breasts (or thighs trimmed of excess fat)
• 1 tablespoon olive oil
• 1 small onion, finely diced
• 3–4 garlic cloves, minced
• 1 (28-ounce) can crushed tomatoes or tomato puree
• 1 (14.5-ounce) can diced tomatoes (no salt added if preferred)
• 2 tablespoons tomato paste
• 1 teaspoon dried oregano
• 1 teaspoon dried basil
• 1/2 teaspoon red pepper flakes (optional)
• 1 teaspoon sugar or a pinch of baking soda (to balance acidity; optional)
• Salt and black pepper, to taste
• Fresh basil or parsley, chopped (optional, for garnish)
• Grated Parmesan or shaved pecorino (optional, for serving)
• Nonstick cooking spray

Method

 

1. Prep the oven and squash: Preheat your oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise. Scoop out the seeds with a spoon.
2. Season and roast: Spray the cut sides lightly with cooking spray and season with salt and pepper. Place cut-side down on a parchment-lined baking sheet. Roast for 35–45 minutes, or until the flesh is tender and easily shreds with a fork.
3. Start the sauce base: While the squash roasts, heat the olive oil in a large skillet over medium heat. Add the diced onion with a pinch of salt and cook 3–4 minutes until softened. Stir in the garlic and cook 30 seconds until fragrant.
4. Add tomatoes and seasonings: Pour in crushed tomatoes, diced tomatoes, and tomato paste. Stir in oregano, basil, red pepper flakes (if using), and a small pinch of sugar or baking soda to reduce acidity. Season with salt and pepper. Simmer uncovered on low for 15–20 minutes, stirring occasionally, until slightly thickened.
5. Cook the chicken: Pat the chicken dry and season with salt and pepper. You have two options: Skillet: Add a touch of oil to a separate skillet over medium heat. Cook the chicken 5–6 minutes per side, until cooked through (165°F/74°C). Rest 5 minutes, then slice or dice.
6. Poach and shred: Simmer chicken gently in salted water for 12–15 minutes, then shred with forks. This keeps it lean and tender.
7. Add chicken to sauce: Stir the cooked chicken into the marinara and simmer 5 more minutes so flavors meld. Taste and adjust salt, pepper, or herbs as needed.
8. Shred the squash: Remove squash from the oven and let cool a few minutes. Use a fork to scrape the flesh into long strands. Transfer to a bowl and season lightly with salt and pepper.
9. Assemble for meal prep: Divide the spaghetti squash among 4–5 meal-prep containers. Top each with a generous portion of marinara chicken. Add fresh basil or parsley if you like. Finish with a sprinkle of Parmesan, if using.
10. Let it cool: Allow containers to cool with lids off for 10–15 minutes before sealing to avoid condensation.

What Makes This Recipe So Good

• Light but hearty: Spaghetti squash gives you that twirlable, pasta-like feel with a fraction of the calories.
• Protein-packed: Lean chicken adds staying power, so you’re full and energized after eating.
• Meal-prep friendly: It reheats beautifully and keeps its texture for days, making it ideal for weekday lunches or dinners.
• Simple ingredients: Pantry staples like canned tomatoes, garlic, and herbs come together quickly.
• Customizable: Keep it classic or add veggies, spices, or cheese to suit your style.

What You’ll Need

• 1 large spaghetti squash (about 3–4 pounds)
• 1–1.25 pounds boneless, skinless chicken breasts (or thighs trimmed of excess fat)
• 1 tablespoon olive oil
• 1 small onion, finely diced
• 3–4 garlic cloves, minced
• 1 (28-ounce) can crushed tomatoes or tomato puree
• 1 (14.5-ounce) can diced tomatoes (no salt added if preferred)
• 2 tablespoons tomato paste
• 1 teaspoon dried oregano
• 1 teaspoon dried basil
• 1/2 teaspoon red pepper flakes (optional)
• 1 teaspoon sugar or a pinch of baking soda (to balance acidity; optional)
• Salt and black pepper, to taste
• Fresh basil or parsley, chopped (optional, for garnish)
• Grated Parmesan or shaved pecorino (optional, for serving)
• Nonstick cooking spray

Step-by-Step Instructions

1. Prep the oven and squash: Preheat your oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise.

   Scoop out the seeds with a spoon.

2. Season and roast: Spray the cut sides lightly with cooking spray and season with salt and pepper. Place cut-side down on a parchment-lined baking sheet. Roast for 35–45 minutes, or until the flesh is tender and easily shreds with a fork.
3. Start the sauce base: While the squash roasts, heat the olive oil in a large skillet over medium heat.

   Add the diced onion with a pinch of salt and cook 3–4 minutes until softened. Stir in the garlic and cook 30 seconds until fragrant.

4. Add tomatoes and seasonings: Pour in crushed tomatoes, diced tomatoes, and tomato paste. Stir in oregano, basil, red pepper flakes (if using), and a small pinch of sugar or baking soda to reduce acidity.

   Season with salt and pepper. Simmer uncovered on low for 15–20 minutes, stirring occasionally, until slightly thickened.

5. Cook the chicken: Pat the chicken dry and season with salt and pepper. You have two options:
   • Skillet: Add a touch of oil to a separate skillet over medium heat.

     Cook the chicken 5–6 minutes per side, until cooked through (165°F/74°C). Rest 5 minutes, then slice or dice.

   • Poach and shred: Simmer chicken gently in salted water for 12–15 minutes, then shred with forks. This keeps it lean and tender.
6. Add chicken to sauce: Stir the cooked chicken into the marinara and simmer 5 more minutes so flavors meld.

   Taste and adjust salt, pepper, or herbs as needed.

7. Shred the squash: Remove squash from the oven and let cool a few minutes. Use a fork to scrape the flesh into long strands. Transfer to a bowl and season lightly with salt and pepper.
8. Assemble for meal prep: Divide the spaghetti squash among 4–5 meal-prep containers.

   Top each with a generous portion of marinara chicken. Add fresh basil or parsley if you like. Finish with a sprinkle of Parmesan, if using.

9. Let it cool: Allow containers to cool with lids off for 10–15 minutes before sealing to avoid condensation.

Storage Instructions

• Refrigerator: Store in airtight containers for up to 4 days.
• Freezer: Freeze for up to 3 months.

  For best texture, freeze the squash and sauce separately if possible.

• Reheating: Microwave on medium power 2–3 minutes, stirring halfway. On the stovetop, heat gently in a covered skillet with a splash of water.
• Thawing: Thaw overnight in the fridge for even reheating and better texture.

Benefits of This Recipe

• Lower calorie, higher volume: Spaghetti squash is naturally low in calories and high in water and fiber, so you can enjoy a generous portion.
• Steady energy: The protein from chicken helps keep you full and supports your goals, whether it’s weight management or building healthy habits.
• Budget-friendly: Canned tomatoes, dried herbs, and a single squash go a long way.
• Gluten-free and flexible: Great for different dietary needs, with easy adjustments for dairy-free or low-sodium.
• Easy to scale: Double the sauce and roast a second squash to cover a whole week.

What Not to Do

• Don’t over-roast the squash: It turns mushy and watery. Check at 35 minutes and stop when it shreds easily but holds strands.
• Don’t skip seasoning the squash: A little salt and pepper make a big difference since spaghetti squash is mild.
• Don’t boil the sauce too aggressively: A rapid boil can make it sharp and reduce too quickly.

  Gentle simmer is best.

• Don’t add too much oil: It’s a low-calorie dish—measure the olive oil to keep calories in check.
• Don’t seal hot containers: Steam causes soggy squash and condensation. Cool briefly before closing.

Recipe Variations

• Veggie boost: Add mushrooms, spinach, zucchini, or bell peppers to the sauce. Sauté with the onion for extra volume and nutrients.
• Spicy arrabbiata: Increase red pepper flakes and add a pinch of smoked paprika for heat and depth.
• Herb-forward: Stir in fresh basil, parsley, or a touch of fresh oregano right before serving for brightness.
• Creamy twist: Swirl in a spoonful of light ricotta or a splash of half-and-half for a rosé-style sauce without many extra calories.
• Cheesy top: Finish with a small handful of shredded part-skim mozzarella and broil briefly to melt.
• Different proteins: Try ground turkey, lean Italian chicken sausage, or meatless crumbles for a similar feel.
• Sheet pan shortcut: Roast chicken breasts alongside the squash, then chop and mix into the sauce to save dishes.

FAQ

How do I pick a good spaghetti squash?

Choose one that feels heavy for its size with a firm, matte rind and no soft spots.

A dry, intact stem is a good sign. Avoid squash with cracks or glossy skin, which can indicate overripeness.

Can I cook the squash in the microwave?

Yes. Pierce the whole squash several times with a knife, microwave 4–5 minutes to soften slightly, then halve carefully.

Place cut-side down in a microwave-safe dish with a little water and cook 8–12 more minutes until tender. The oven gives better flavor and texture, but this is faster.

What’s the best way to keep the sauce from tasting too acidic?

Simmer it gently to mellow the tomatoes. Add a teaspoon of sugar or a pinch of baking soda to balance acidity.

Also, a small knob of butter (optional) can round out the flavor without many calories.

How many servings does this make?

Typically 4 to 5 meal-prep portions, depending on the size of your squash and how generous you are with the sauce. Aim for about 1 to 1 1/2 cups of squash and 3–4 ounces of chicken per container.

Can I make it dairy-free?

Absolutely. Skip the Parmesan or use a dairy-free alternative.

The recipe is naturally dairy-free without the cheese.

Is this freezer-friendly?

Yes. For best results, freeze the marinara chicken separately and the squash in its own container. This helps preserve the texture.

Thaw in the fridge, then reheat gently.

Can I use store-bought marinara?

You can. Choose a lower-sugar, lower-sodium brand to keep it light. Warm it up, add garlic and herbs to taste, and stir in the cooked chicken.

Final Thoughts

This Low Calorie Meal Prep Spaghetti Squash & Marinara Chicken is the kind of recipe that makes healthy eating feel easy.

It’s comforting, flavorful, and simple to batch-cook for the week. With a few pantry ingredients and a single roasting pan, you get a hearty meal that checks all the boxes—balanced, budget-friendly, and satisfying. Keep it classic or make it your own with the variations above, and enjoy a lighter take on a familiar favorite.