Low-Potassium Diet: What to Know

Medically Reviewed by Christine Mikstas, RD, LD on March 06, 2024
2 min read

Every time you eat a banana or a baked potato with the skin on (not just the tasty buttered insides), you're getting potassium. This essential mineral keeps your muscles healthy and your heartbeat and blood pressure steady.

If you have a heart or kidney condition, though, your doctor may recommend a low-potassium diet. Your kidneys are responsible for keeping a healthy amount of potassium in your body. If they're not working right, you may get too much or too little.

If you have too much potassium in your blood, it can cause cardiac arrest -- when your heart suddenly stops beating.

If you have too little potassium in your blood, it can cause an irregular heartbeat. Your muscles may also feel weak.

Most foods have potassium. To keep your levels low, avoid or eat less than a half-cup a day of these high-potassium foods:

High-potassium fruits:

  • Apricots
  • Bananas
  • Cantaloupe
  • Dried fruit
  • Honeydew melon
  • Kiwi
  • Mango
  • Nectarines
  • Oranges and orange juice
  • Papaya
  • Pomegranate and pomegranate juice
  • Prunes and prune juice
  • Pumpkin
  • Raisins

High-potassium vegetables:

  • Acorn squash, butternut squash, Hubbard squash
  • Avocado
  • Artichoke
  • Beets
  • Baked beans, black beans, refried beans
  • Broccoli (cooked)
  • Brussels sprouts
  • Kohlrabi
  • Lentils
  • Okra
  • Parsnips
  • Potatoes (white and sweet)
  • Rutabagas
  • Spinach (cooked)
  • Tomatoes, tomato sauce, and tomato paste
  • Vegetable juice

Other high-potassium foods:

  • Bran products
  • Chocolate
  • Coconut
  • Creamed soups
  • French fries
  • Granola
  • Ice cream
  • Milk (buttermilk, chocolate, eggnog evaporated, malted, soy and milkshakes)
  • Miso
  • Molasses
  • Nuts
  • Peanut butter
  • Potato chips
  • Salt substitutes
  • Seeds
  • Tofu
  • Yogurt

The list of high-potassium foods may feel a bit overwhelming, but remember, for every high-potassium food to avoid, there's at least one low-potassium food to enjoy.

The recommended serving size for these low-potassium foods is 1/2 cup. You don't want to overdo it. Too much of a low-potassium food makes it a high-potassium food.

Low-potassium fruits:

  • Apples (plus apple juice and applesauce)
  • Blackberries
  • Blueberries
  • Cranberries
  • Fruit cocktail
  • Grapes and grape juice
  • Mandarin oranges
  • Peaches
  • Pears
  • Pineapple and pineapple juice
  • Plums
  • Raspberries
  • Strawberries
  • Tangerine
  • Watermelon

Low-potassium vegetables:

  • Alfalfa sprouts
  • Asparagus (6 raw spears)
  • Broccoli (raw or cooked from frozen)
  • Cabbage
  • Carrots (cooked)
  • Cauliflower
  • Celery (1 stalk)
  • Corn (half an ear if it's on the cob)
  • Cucumber
  • Eggplant
  • Green beans or wax beans
  • Kale
  • Lettuce
  • White mushrooms (raw)
  • Onion
  • Parsley
  • Peas (green)
  • Peppers
  • Radish
  • Water chestnuts
  • Watercress
  • Yellow squash and zucchini

Other low-potassium foods:

  • Bread (not whole grain)
  • Cake (angel or yellow)
  • Coffee (8 ounces)
  • Cookies (no nuts or chocolate)
  • Noodles
  • Pasta
  • Pies (no chocolate or high-potassium fruit)
  • Rice
  • Tea (16 ounces max)

Here's a trick: You can lower the potassium levels in certain vegetables by a cooking process called leaching. Try this on white and sweet potatoes, carrots, beets, winter squash, and rutabagas.

Fill a pot with warm water. Peel your vegetable and rinse it in warm water, then cut it into 1/8th-inch-thick slices. Rinse the slices and soak them in the pot for 2 hours. When you pull them out, rinse them again with warm water. Drain the water in the pot, fill it again, and cook your vegetable.

If you want to leach more than one vegetable at a time, soak them in 10 times the amount of water to the amount of vegetables. And when you cook them, use five times more water than vegetables.

Based on the amount of potassium that's right for you, ask your doctor or nutritionist how to balance high- and low-potassium foods in each meal.