Chronic kidney disease (CKD) affects roughly 1 in 10 adults in the UK, and what you eat has a measurable impact on how quickly the condition progresses. This guide pulls together what NHS dietitians, NICE guideline NG203 and the British Dietetic Association (BDA) currently recommend, in plain English.
Why diet matters in CKD
The kidneys regulate fluid, electrolytes (especially sodium, potassium and phosphate), acid–base balance and the activation of vitamin D. When kidney function falls, these jobs become harder, and food becomes one of the main levers you can pull at home to support them.
The five UK dietary priorities in CKD
1. Reduce salt to under 6 g a day
Public Health guidance for adults in the UK is a maximum of 6 g of salt (about 2.4 g sodium) per day. For people with CKD the message is the same — and most of that salt is hidden in bread, processed meats, sauces and ready meals rather than the salt shaker.
2. Eat enough — but not too much — protein
NICE NG203 advises against either very low or very high protein intakes in CKD. The BDA's general adult target of around 0.75 g protein per kg of body weight per day is a reasonable starting point for most people in early-stage CKD, adjusted by a renal dietitian as kidney function changes.
3. Watch potassium only if your blood test says so
Potassium restriction is not for everyone with CKD. It is reserved for people whose blood potassium is rising. If your renal team has flagged this, the NHS leaflet on potassium and kidney disease lists which fruits, vegetables and cooking methods (such as boiling potatoes) help bring intake down.
4. Be aware of phosphate, especially additives
Inorganic phosphate added to processed foods (look for E338–E343, E450–E452) is absorbed far more efficiently than the phosphate naturally present in food. Cutting back on cola drinks, processed cheese and many ready meals is often more useful than avoiding dairy.
5. Get your fluids right
Most people with early CKD do not need to restrict fluids. Aim for pale-straw urine. Restriction only applies in advanced CKD or dialysis, on the advice of your renal team.
What about supplements?
The NHS recommends that all UK adults consider a 10 microgram vitamin D supplement during autumn and winter. Beyond that, supplements in CKD should be discussed with your GP or renal pharmacist — some (high-dose vitamin A, certain herbal products, and effervescent tablets high in sodium) can do more harm than good.
Bottom line
The kidney-friendly diet in the UK is closer to the Eatwell Guide than to a long list of "forbidden" foods. Salt down, protein moderate, processed foods reduced, vitamin D considered in winter — and individualised advice from a renal dietitian whenever your blood tests change.