Most simple soups built from the right ingredients can stay well under 200 mg of potassium per serving, which is the general threshold for a low-potassium food. The key is choosing your base, vegetables, proteins, and starches carefully, because some of the most common soup ingredients (potatoes, tomatoes, beans) are among the highest-potassium foods you can eat.
What Counts as Low Potassium
A food is generally considered low in potassium when it contains less than 200 mg per serving. That’s the cutoff the National Kidney Foundation uses, and it’s a practical number to keep in mind while building a bowl of soup. For context, a single medium potato with the skin delivers over 600 mg, and half a cup of cooked spinach hits about 420 mg. A soup loaded with those ingredients can easily push past a full meal’s worth of potassium in just the broth and vegetables alone.
Best Vegetables for Low-Potassium Soup
Green beans, cabbage (both green and red), and cooked carrots are some of the most reliable low-potassium vegetables for soup. A half-cup serving of any of these stays comfortably under the 200 mg mark, and they hold up well during long simmering. Other good options include celery, onions, corn, and bell peppers.
These vegetables also bring enough flavor and texture to make a satisfying soup without needing to rely on high-potassium additions. A simple combination of carrots, green beans, and cabbage in a clear broth gives you a hearty base that you can season and build on without worrying about the potassium climbing too fast.
Starches That Keep Potassium Low
White rice, plain pasta (penne, spaghetti, egg noodles), and regular noodles are all significantly lower in potassium than potatoes and make excellent soup additions. Renal dietitians regularly recommend pasta, rice, and noodles as potato alternatives for exactly this reason. Stick with plain varieties. Filled pastas like ravioli tend to have higher potassium because of the cheese or meat stuffed inside.
If you want the heartiness of potato in your soup, there’s a workaround. Cutting potatoes into small cubes and boiling them in a large pot of water before adding them to soup can reduce their potassium content by roughly 50%. Shredding potatoes before boiling drops potassium by about 75%. Simply soaking raw potatoes without boiling, however, does not meaningfully reduce potassium levels. So the cooking step matters: the potassium leaches into the boiling water, which you then discard.
Proteins to Add
Chicken, ground beef, fish, eggs, and tofu all work in low-potassium soups. A one-ounce portion of cooked chicken, beef, or fish provides about 7 grams of protein without contributing excessive potassium, especially in the small quantities typical for soup. Egg whites are another easy add-in: think egg drop soup, which is naturally low in potassium when made with a simple broth.
Tofu is a solid plant-based option. Firm or extra-firm tofu cubed into soup provides about 6 grams of protein per quarter cup. Soft or silken tofu blended into a creamy soup base gives about 3 grams per serving. Both are reasonable potassium choices compared to the beans and lentils that often replace meat in vegetarian soups.
High-Potassium Ingredients to Skip
Some of the most popular soup ingredients are potassium-dense, and swapping them out makes the biggest difference:
- Potatoes and sweet potatoes: A single medium potato can exceed 600 mg. If you include them, use the boiling and draining method described above.
- Spinach and Swiss chard: Half a cup of cooked spinach has about 420 mg, and Swiss chard is even higher at around 480 mg. Swap in green beans or cabbage instead.
- Kidney beans, navy beans, lentils, and split peas: These deliver roughly 350 mg per half cup. They’re a major potassium source in minestrone, chili, and split pea soup.
- Tomatoes: Tomato-based broths and canned crushed tomatoes are high in potassium. A cream or clear broth base is a safer starting point.
Watch Out for “Low Sodium” Canned Soups
This is one of the most common traps for people watching their potassium. Many low-sodium and reduced-sodium canned soups replace regular salt with potassium chloride to maintain a salty taste. The sodium on the label goes down, but the potassium goes up, sometimes substantially. The swap isn’t always obvious because potassium chloride can appear simply as “salt substitute” or “potassium chloride” deep in the ingredients list.
If you’re buying canned soup, check the nutrition label for potassium content per serving, not just sodium. Some brands now list potassium as a required line item, making this easier. When the label doesn’t list it, scan the ingredients for potassium chloride. Regular-sodium versions may actually be lower in potassium than their “healthier” low-sodium counterparts.
Soups That Tend to Be Lower in Potassium
Certain classic soups are naturally better choices because of their ingredient profiles:
- Chicken noodle soup: Built on broth, egg noodles, carrots, celery, and chicken, this is one of the safest options. Every component is relatively low in potassium.
- Chicken and rice soup: Similar to chicken noodle, with white rice replacing the pasta. Both the rice and broth keep potassium modest.
- Cabbage soup: Green cabbage simmered in broth with carrots and onions stays low across the board.
- Egg drop soup: A simple broth with beaten egg stirred in. Very low in potassium and easy to make at home.
- Clear vegetable soup: As long as you build it with green beans, carrots, corn, cabbage, or celery rather than tomatoes, potatoes, or greens like spinach.
Soups to be more cautious with include minestrone (beans and tomatoes), split pea soup, baked potato soup, tomato soup, and any cream of spinach or greens-based soup.
Building a Bowl From Scratch
Making soup at home gives you the most control. Start with a clear chicken, beef, or vegetable broth. Season with garlic, onion, thyme, or bay leaves rather than salt substitutes. Add a starch like white rice or plain noodles, a couple of low-potassium vegetables, and a protein. A bowl built this way can realistically stay under 250 to 300 mg of potassium total, depending on portion size.
One practical tip: cooking vegetables in the soup broth does release some of their potassium into the liquid. If you’re trying to keep levels as low as possible, you can boil vegetables separately, discard that water, and then add the cooked vegetables to your soup near the end. This extra step matters most for root vegetables; for already-low-potassium ingredients like green beans or cabbage, the difference is small enough that most people don’t need to bother.