What is potassium?
Potassium is a mineral that is found naturally in many foods and drinks. It helps control the balance of fluids in the body; it is also needed for your muscles, such as your heart, to work properly.
Why do you need to follow a low potassium diet?
The amount of potassium in your blood is normally controlled by your kidneys. However, when your kidneys aren’t working properly the amount of potassium in your blood can build up.
High levels of potassium can be dangerous, as it can affect your heartbeat. To control the potassium levels in your blood you may need to reduce the amount of potassium in your diet.
You should only follow a low potassium diet if you have been advised to do so by a qualified health professional. If you are following any other dietary restrictions, discuss with your dietitian how to also restrict your potassium intake while following these other restrictions. You must continue to follow a low potassium diet unless told to stop by your dietitian or other qualified health professional.
What can I do to control my potassium levels?
- regular bowel movements can help prevent potassium from building up in the blood. Consider increasing your fibre intake if you are struggling with constipation. Fibre is found in fruit, vegetables, wholegrains, beans, pulses, lentils, nuts and seeds.
- although all fruit and vegetables contain potassium, it is still important to include these in your diet. Aim to limit your intake of fruits and vegetables to four servings per day using the lower potassium alternatives listed below.
- tinned fruit is lower in potassium than fresh – always drain off and discard the juice or syrup before eating.
- salt substitutes and low-sodium salts may contain potassium additives such as potassium chloride. Avoid these alongside products labelled “low sodium” or “reduced salt” as they may be higher in potassium.
- you may not need to limit all high-potassium foods; consider reducing your portion sizes, or how frequently you eat them.
- if you have diabetes, high blood glucose can increase potassium levels in the blood; speak to your dietitian or diabetes team if you require support in optimising your blood glucose control.
- recent evidence has shown that following a plant-based diet can lower potassium levels. Speak with your dietitian if you would like advice on following a plant-based diet.
Cooking tips for a low potassium diet
The way potatoes and vegetables are cooked can affect their potassium content. Consider the following when cooking:
- cut potatoes and vegetables into small pieces and boil in a large amount of water. After boiling, throw the cooking water away Do not use this water to make soup, gravy, stocks or sauces
- once boiled, potatoes and vegetables can be roasted, mashed, fried or added to sauces
- limit boiled potatoes to one serving of 2-3 egg-sized boiled potatoes per day
- Try to avoid potatoes and vegetables that have been steamed, microwaved, baked or fried unless they have been boiled first. This includes potato products such as chips, waffles, potato scones, hash browns, or instant mashed potatoes.
- soak dried pulses such as beans, lentils, and chickpeas in plenty of water overnight; discard the water, and boil before adding to dishes. Tinned pulses are generally lower in potassium, but make sure to drain and rinse these before eating
- milk is high in potassium and may need to be limited. Consider diluting it down using water or plant-based alternatives such as rice, almond, or oat milks
- canned plum tomatoes that are drained are lower in potassium than fresh tomatoes; avoid tomato puree – you may have a meal with a tomato based sauce if you’re not having potatoes on the same day. One third of a 400g tin of tomatoes or one serving of a ready-made sauce would be equivalent to your daily potato allowance.
If you have a vegetarian diet or choose to have a vegetarian meal you can increase the amount of pulses in your diet.
Pulses are the main source of protein in a vegetarian diet. When used as the alternative to meat, fish, and poultry they do not need to be included in the vegetable’s allowances.
A vegetarian meal can include 120g (three heaped tablespoons of):
- dried, boiled chickpeas*
- dried, boiled broad beans
- dried, boiled black-eyed peas
- dried, boiled green and brown lentils
- dried, boiled red lentils
- dried, boiled mung beans
- canned red kidney beans
- canned butter beans
- baked beans
*Canned chickpeas are lower in potassium and therefore you can have double the portion (up to six heaped tablespoons)
The following are higher in potassium with smaller recommended servings:
- soya beans 80g (two heaped tablespoons)
- Aduki beans 60g (1.5 heaped tablespoons)
Additional dietary needs
If you have additional dietary needs, such as diabetes, low salt, low phosphate, allergies, or intolerances, these must be considered when making your choices. Make sure you discuss these with your dietitian.
|
Food Group |
Reduce intake of |
Lower potassium alternatives |
| Fruits | Bananas, avocado, coconut, persimmon, Goji berries, dried fruit (including raisins, sultanas, figs, and dates), grapefruit, nectarines, rhubarb, star fruit, pomegranates, jack fruit, durian, and oranges. |
Limit to two servings (80 grams) per day.
|
| Vegetables | Mushrooms, plantain, sweet potato, okra, spinach, sundried tomatoes, artichoke, karela or bitter melon, asparagus, Brussels sprouts, beetroot, fennel, kohlrabi leek, parsnip, betel leaves, kantola. |
Limit to two portions (three to four tbsp) or one small salad:
|
| Starchy carbohydrates | Soya flour, cereals containing bran/dried fruits or nuts/chocolate (e.g., All Bran, Muesli, Sultana Bran). Cassava, yams, quinoa, bajra, jowar, ragi. Chickpea or potato flour. |
Wheat, pasta, noodles, rice, couscous, or bread. Rolls, bagels, croissants, English muffins. Naan bread (one or two large or one mini), pitta, chapattis, puri. Wraps and crackers without nuts/seeds. Boiled barley, bulgar wheat, semolina. Plain breakfast cereals and porridge (e.g., Weetabix, Rice Krispies). |
| Protein foods | Nuts and seeds (portions over 30g). Peanut butter. Soya beans. Ham and other 'delicatessen' meats. Processed meats e.g., Spam. |
All fresh or frozen meat, poultry, and fish. Quorn, seitan, dhal, tofu, tempeh, or paneer. Eggs. Hummus, beans and pulses (tinned, rinsed and drained). |
| Dairy foods | Limit milk to 300ml daily, including cow’s, sheep’s, goat’s and plant- based milk eg. soya. Milky puddings, yoghurts, raita, lassi. Milkshakes, evaporated milk, condensed milk, coconut milk/creamed coconut. Milk powders. |
Butter, reduced-fat spread, margarine, ghee, all cooking oils. Cream, sour cream, crème fraiche. Cheese. Rice and oat milk. Limit ice cream to two scoops (120g) two to three times per week. |
| Drinks | Instant coffee, 'barista' coffees including espresso, latte, cappuccino, mocha, etc. Hot chocolate and cocoa, malted drinks (e.g., Horlicks, Ovaltine). Beer, lager, cider, port, wine, strong ale, stout. Most fruit/vegetable juices and smoothies. Coconut water. |
Tea (including fruit, herbal). Fizzy drinks e.g., ginger beer, lemonade, cola. Fruit squash. Tonic and flavoured water. Spirits and liqueurs e.g., vodka, rum, gin, whiskey. Barley water. |
| Desserts and snacks | Crisps – potato, cassava, plantain, vegetable. Nut brittle, sesame snacks, trail mix. Bombay mix, chevda. Chocolate, toffee, caramel fudge, liquorice, marzipan. Bhajis, pakora, samosas. |
Plain biscuits, shortbread. Arctic roll, cream horns, ginger cakes, iced buns, sorbet, Pavlova. Pancakes, scones, doughnuts. Marshmallows, Turkish Delight, ice lollies. Plain sponge cake, meringues. Jelly. |
| Miscellaneous | Brown sauce, chocolate spreads, instant soup powder, pesto, tahini, tamarind paste, tomato ketchup, yeast extracts e.g., Marmite, Vegemite. |
Apple sauce, gravy granules/stock cube, herbs and spices, honey/syrups, jam/preserves/lemon curd, mint sauce, pickles/chutney, vinegar. Popcorn, plain rice crackers, breadsticks. Mayonnaise, salad cream, salad dressings. |