Good news if you are eating low carb: Alfredo sauce is naturally close to keto already, since the classic recipe uses no flour at all. This version locks that in, with cream cheese for extra body and an optional bit of xanthan gum if you want it thicker, all while staying under 2 grams of net carbs per serving.
Keto Alfredo Sauce (Low Carb)
A naturally low carb Alfredo sauce made with butter, heavy cream, and Parmesan, with no flour or starch thickeners.
Ingredients
- 1/2 cup unsalted butter (1 stick)
- 2 cups heavy cream
- 3 cloves garlic, minced
- 2 cups Parmesan cheese, grated
- 2 ounces cream cheese, softened
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/8 teaspoon xanthan gum (optional, for extra thickness)
Instructions
- Melt the butter in a saucepan over medium heat.
- Add the garlic and cook for 1 minute, until fragrant.
- Pour in the heavy cream and bring to a gentle simmer, stirring often.
- Whisk in the cream cheese until fully smooth.
- Lower the heat and add the Parmesan a handful at a time, whisking until melted before adding more.
- Season with salt and pepper.
- If you want the sauce thicker, sprinkle in the xanthan gum while whisking constantly, then simmer 1 more minute.
- Serve immediately over zucchini noodles, shirataki noodles, or low carb pasta.
Notes
This sauce is naturally low carb on its own, since there is no flour or cornstarch in it. The carbs that do exist come mostly from the small amount of lactose in the dairy.
If you use xanthan gum, add only a little at a time. It thickens fast and too much will make the sauce gluey instead of silky.
Why Alfredo Sauce Fits a Keto Diet
A lot of cream sauces use flour or cornstarch to thicken, which adds carbs. This recipe skips that entirely. Butter, heavy cream, and Parmesan are all naturally low in carbs on their own, so the sauce stays keto friendly without needing any special swaps. The small amount of carbs that remain come from lactose in the dairy, not from any added starch.
What to Serve It Over
Regular pasta will undo the low carb math here, so pair this sauce with something lower carb instead. Zucchini noodles, spaghetti squash, or shirataki noodles are all common choices. For the full nutrition breakdown of this sauce, see our Alfredo sauce nutrition facts page.
Tips for the Best Texture
- Cream cheese adds body without adding many carbs, do not skip it if you want a thicker sauce.
- If using xanthan gum, whisk it in slowly. A little goes a long way.
- Keep the heat low once the cheese goes in, the same rule that applies to any Alfredo sauce.
Storage
Store in a sealed container in the fridge for up to 4 days. Reheat gently over low heat, see our how to reheat Alfredo sauce page for the full method, since cream sauces need a slow reheat to stay smooth.
Common Mistakes to Avoid
- Adding flour or cornstarch out of habit. Neither is needed here, and both add carbs you do not want in a keto recipe.
- Using too much xanthan gum. It thickens fast. Start with a small pinch and add more only if needed.
- Forgetting to check the carb count of what you serve it over. The sauce itself is low carb, but regular pasta will add far more carbs than the sauce does.
Net Carbs vs Total Carbs
For a sauce like this, with no fiber to speak of, net carbs and total carbs come out to roughly the same number. This is different from many vegetables and whole grains, where fiber lowers the net carb count. The 2 grams listed for this recipe applies either way you are counting.
Make It Ahead
This sauce can be made up to 3 days ahead. Store it in a sealed container in the fridge, and reheat it gently over low heat. Cream cheese based sauces can thicken quite a bit once cold, so have a splash of heavy cream ready to whisk in while reheating.