Low Potassium Diet Information for Kidney Patients

What is potassium?

Potassium is a mineral found in many foods. It helps our nerves, muscles and heart to work well.

Our kidneys help to control the level of potassium in the blood. Extra potassium leaves the body in the urine.

Why is my potassium high?

  • Your kidneys are not working well.
  • You may be eating a high potassium diet.
  • There are other medical reasons which might cause your potassium to be high.

What should my potassium be?

______mmol/l. The dietitian will advise you on this.

Why do I need to control potassium in the blood?

Both high and low potassium can change the way your heart beats.

Can I tell if my potassium is high?

No. The only reliable way is a blood test.

What can I do to control high blood potassium? 

  • Choose low potassium foods
  • Ensure your bowels open regularly
  • If you have diabetes keep your blood glucose in your target range
  • If you have dialysis, attend all of your sessions.

This page contains advice on: 

  • High potassium foods and low potassium options
  • Information on the best way to cook foods
  • Choosing the right portion size to eat

Do I have to avoid all high potassium foods?

You may not need to. Your dietitian can advise you.

Are there any foods I don’t have to reduce?

Meat, fish, eggs, and cheese contain potassium but are good sources of protein. You should not reduce these foods unless advised to do so.

Pasta, rice, couscous, bread and noodles are low in potassium. You do not need to reduce these. It is also ok to eat wholegrains.

Can I eat fruit and vegetables?

Yes. Aim for five servings of lower potassium fruit and vegetables per day.

Drinks

Milk and coffee are high in potassium. Try to limit these to 1/2 pint of milk and 1 cup of coffee per day.

Low potassium

Tea, fruit squashes, fizzy drinks, dry sherry, liquers, spirits, wine (1 small glass per day), ale, bitter, stout (half pint per day)

High potassium

Coffee, milk, fruit and vegetable juice/smoothies, malted or chocolate drinks (e.g. Ovaltine, Cocoa), condensed and evaporated milk, cider, strong ale

Vegetables

Low potassium

Asparagus, aubergine, baby corn, beansprouts, pickled beetroot, broccoli, cabbage, carrots, cauliflower, cucumber, cress, leeks, lettuce (1 small bowl), mange tout, marrow, tinned mushrooms, onion, peas, peppers, pumpkin, runner beans, spring greens, kale, sweetcorn (tinned), swede, turnip, tomato (1 small), tinned tomato (1/4 tin). Potatoes - boil first. You can then mash, fry or roast. Eat in smaller amounts: broad beans, squash, sprouts, watercress, spring onions, green beans, radishes, celery.

High potassium

Artichoke, fresh beetroot, celeriac, corn on cob, sweet potato, courgette, fennel, fresh mushrooms, Swiss chard, parsnips, tomato puree, tomato pasta sauces, spinach, okra, cassava, yam, plantain, Chinese leaves, pak choi.Chips, jacket potatoes, frozen potato e.g. oven chips, potato waffle.

For more information on portion sizes, ask the dietitian.

Fruit

Low potassium

Apple, strawberries, raspberries, blueberries, gooseberries, blackberries, passion fruit, grapefruit (1/2), nectarine (small), lychees, grapes (handful), fruit cocktail, melon or watermelon (1 small slice), pear, mango, satsumas, plum (1), pineapple, cherries, orange, peach, tinned apricots, tinned rhubarb, kiwi.

High potassium

Fresh apricots, avocado, bananas, blackcurrants, damsons, figs, greengages, guava, pomegranate, fresh rhubarb, dried fruit e.g. dates, raisins, sultanas, prunes. Star fruit should be avoided by kidney patients.

Snack foods

Low potassium

Corn, maize, wheat snacks, breadsticks, popcorn, sweets, marshmallows, Turkish Delight. Chocolate: Limit to 4 squares or 1 small bar (e.g. Kit-Kat, Milky-Way, Twix). Avoid snacks that have added potassium chloride. Ask your dietitian for a list of suitable options.

High potassium

Nuts, Bombay mix, potato crisps, Twiglets, liquorice. Chocolate containing nuts or dried fruit.

Cereal, cakes, biscuits

Low potassium

Plain cereals such as cornflakes, porridge, Shredded Wheat, Weetabix. Cakes & biscuits: plain, jam or cream filled e.g. madeira, Battenberg, doughnuts, tarts, plain scones, digestives, wafers.

High potassium

Cereals containing dried fruit & nuts (e.g. muesli, Fruit and fibre, Sultana Bran), All-Bran, Bran buds, Bran Flakes, Oat crisp. Cakes and biscuits containing dried fruit, nuts, chocolate.

Spreads

Low potassium

Butter, margarine, jam, marmalade, honey, lemon curd.

High potassium

Chocolate, peanut butter, tahini, yeast extract, treacle.

Soups

Low potassium

Tinned cream of chicken, packet chicken noodle, oxtail soup.   

High potassium

Vegetable and tomato based soups.

Seasonings/condiments

Low potassium

Use ordinary salt sparingly. Pepper, herbs, spices, ginger, garlic, lemon juice, chilli sauce, mint sauce, mustard, mayonnaise, salad cream, tartare sauce.

High potassium

Low sodium salts e.g. LoSalt, Solo (these contain potassium chloride). Tomato ketchup / brown sauce - limit to 1 tablespoon.

Foods high in salt and sugar: How to reduce the potassium in potatoes & vegetables:

  • Peel potatoes, cut up and boil in water. Do not use this water for gravy, soups, or sauces.
  • Boil vegetables and potatoes before adding to stir-fries, stews, or casseroles.
  • Part boil before roasting and frying. Avoid steaming, microwaving, and pressure-cooking.
  • Boil cassava, sweet potato and yam if you are having these. Avoid potatoes at that meal.

Potassium chloride:

Avoid foods that contain potassium chloride. Foods that claim to be ‘reduced’ or ‘low’ salt may contain potassium chloride. Check the ingredients list on the food label.

This leaflet gives a full range of low and high potassium foods.

It includes some foods that are high in salt and sugar such as savoury snacks, cakes and sweets. These are included to give a variety of options. You may prefer not to eat these foods if you have been asked to reduce the salt in your diet or if you have diabetes.

What if the foods I eat are not mentioned on this webpage?

You can contact your renal dietitian on 0117 414 5428.

What if I eat a vegetarian or vegan diet?

If your meal does not contain meat, chicken or fish then you can include one of the following:

  • 200g Baked beans
  • 200g Tofu n 200g Quorn
  • 200g lentils* n 200g chickpeas* 
  • 200g beans* (e.g. canned broad, kidney, butter beans, haricot, mung and black eyed beans)
  • 200g of hummus^

* cooked weight ^ lower in protein

How do I reduce the potassium in these foods?

  • Drain, rinse and boil all types of beans and lentils before adding to meals. This includes; curries, stews & casseroles
  • Choose canned beans or lentils as they are lower in potassium
  • If using dried beans or lentils, soak overnight in plenty of water
  • Discard the water used for soaking or boiling.

Are there any vegetarian foods I should avoid?

  • Soya beans, aduki, pigeon and pinto beans are higher in potassium. Reduce or avoid these.
  • Nuts and seeds n If you avoid potatoes, then you can have another portion of beans, lentils or meat alternative.

Ask your dietitian if you need further help.

© North Bristol NHS Trust. Published June 2021. NBT003377

Low Potassium Diet Information for Kidney Patients