A plain-language guide to two minerals that matter in kidney disease — potassium and phosphate — including which everyday foods are naturally higher or lower in each, and why the kidney diet works the way it does.
Not everyone with kidney disease needs to limit potassium or phosphate. Whether you do — and by how much — depends on your CKD stage, your blood test results and your medications. If your kidney function is only mildly reduced, you'll usually be advised to follow a normal healthy diet. Some people are even told to eat more potassium. Your renal dietitian and kidney team set your personal targets from your bloods. This page is general information about how kidney-friendly eating works — not a meal plan or medical advice. Ask your GP for a referral to an Accredited Practising Dietitian.
Search a food to see whether it's naturally lower, moderate or higher in potassium and phosphate. These are general bands per typical serve — not targets.
| Food (typical serve) | Potassium | Phosphate |
|---|
Boiling vegetables in plenty of water and draining (“leaching”) lowers their potassium — useful if a higher-potassium vegetable is a favourite. It doesn't remove all of it.
Healthy kidneys keep blood potassium in a tight range. When kidney function drops, potassium can build up (hyperkalaemia), which can affect the heart — and it often causes no symptoms, which is why your team checks it with blood tests. Whether you need to watch potassium depends on those results and on medicines that raise potassium (such as some blood-pressure tablets).
In kidney disease, phosphate can build up in the blood. Over time, high phosphate pulls calcium from your bones (making them weak) and is linked to heart and blood-vessel problems. Your team checks phosphate and calcium on blood tests and may prescribe phosphate binders — tablets taken with meals that trap phosphate in the gut.
Most kidney-friendly eating also limits salt (which helps blood pressure and fluid). Only some people — mainly those on dialysis — need to limit fluid; many can drink to thirst. Your team will tell you if either applies to you.