Celery root is not a starch in the way potatoes and other root vegetables are. It contains only about 5 to 6% starch, which is dramatically lower than a potato and makes it one of the least starchy root vegetables you can buy. That’s why it’s become a popular swap for potatoes in mashed dishes, gratins, and soups.
How Celery Root Compares to Potatoes
The numbers tell the story clearly. Per 100 grams, celery root has 9.2 grams of carbohydrates and 42 calories. A standard potato has 17.5 grams of carbohydrates and 77 calories for the same weight. That means celery root delivers roughly half the carbs and just over half the calories of a potato.
One cup (156 grams) of raw celery root contains 14 grams of total carbohydrates, 2.8 grams of fiber, and only 2.5 grams of sugar. For a root vegetable, that sugar content is notably low. The fiber also helps slow digestion, which matters for blood sugar management.
Why It Stores Less Starch Than Other Roots
Most root vegetables act as underground energy banks, packing starch into their tissues to fuel the plant’s growth. Celery root works differently. Botanically, it’s not a true root or tuber. It’s a swollen hypocotyl, the region where the stem meets the root system. This fleshy, globe-shaped storage organ grows partly above the soil line and develops more like a turnip than a potato. Its energy storage strategy relies less on starch, which is why it has that lighter, more celery-like flavor instead of the dense, floury quality of a potato.
Blood Sugar Impact: Raw vs. Cooked
Here’s something worth knowing if blood sugar is a concern: celery root’s glycemic index changes substantially depending on how you prepare it. Raw celery root has a glycemic index of about 35, which is low. Cooked celery root jumps to around 85, which is high. That’s a significant difference. Cooking breaks down the cell structure and makes the carbohydrates much easier for your body to absorb quickly.
This doesn’t erase its advantages over potatoes, since the total amount of carbohydrate is still lower. But if you’re managing diabetes or tracking blood sugar closely, eating celery root raw (shredded in salads, for example) will produce a much gentler blood sugar response than eating it mashed or roasted.
Does It Work for Keto and Low-Carb Diets?
Celery root sits in a gray zone for strict keto. With about 11 grams of net carbs per cup (14 grams total carbs minus 2.8 grams of fiber), it’s not as low-carb as cauliflower or zucchini, but it’s far lower than potatoes or sweet potatoes. For someone on a standard keto diet aiming for 20 to 50 grams of net carbs per day, a moderate portion of celery root can fit if you plan around it.
Its real value on low-carb diets is as a textural substitute. Mashed celery root, celery root fries, and celery root gratin all satisfy the craving for something starchy without the carb load of the real thing. The flavor is mild and slightly nutty, with a hint of celery, so it takes well to butter, cream, garlic, and herbs.
Nutritional Benefits Beyond Carbs
Celery root also provides meaningful amounts of vitamin C, vitamin K, and potassium. Vitamin K supports blood clotting and bone health, while potassium helps regulate blood pressure. At 66 calories per cup, it’s a nutrient-dense choice that adds bulk to meals without adding much caloric weight. The fiber content, while modest at 2.8 grams per cup, contributes to digestive health and helps you feel full longer.
Best Ways to Use It as a Potato Substitute
Celery root mash is the most common swap. Peel and cube it, boil until tender, then mash with butter and a splash of cream. The texture is slightly less fluffy than mashed potatoes but surprisingly close. Some people blend half celery root with half potato for a middle ground that cuts carbs while keeping a familiar consistency.
Roasted celery root caramelizes nicely when cut into cubes and cooked at high heat with olive oil and salt. Thin slices work well in gratins layered with cheese. Raw, it can be julienned or grated into a remoulade, the classic French salad dressed with mustard and mayonnaise. Each preparation method changes the texture and glycemic impact, so you have flexibility depending on your goals.