On dialysis, what you eat and drink is a genuine part of your treatment, because dialysis replaces only some of what the kidneys do. Fluid, potassium, phosphate and salt all need attention, and, perhaps surprisingly, protein needs are different from the pre-dialysis kidney diet. The details are individual and set by your renal dietitian from your blood results, so this guide explains the principles rather than numbers, tailored where it helps to Singaporean foods.
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This is general information and does not replace your renal dietitian’s advice; targets are individual and set from your blood tests. Do not use “low-salt” substitutes without approval, as many are high in potassium. Large fluid gains with breathlessness, or a very high potassium, can be dangerous: call 995 for severe breathlessness, collapse or palpitations.
Why fluid matters
Because failing kidneys make little or no urine, the fluid you take in is not removed and builds up in the body between dialysis sessions. Too much fluid causes rapid weight gain, swelling in the legs, ankles and face, breathlessness as fluid affects the lungs, higher blood pressure, and strain on the heart. This is why fluid balance matters so much, and why you are weighed at dialysis to check how much fluid has built up against your target, or “dry”, weight.
Your fluid allowance
Your team usually sets a personal daily fluid allowance, based on how much urine you still pass, your weight and your condition, so it is individual rather than a single figure for everyone. Remember that “fluid” is more than drinks: soups and congee, ice, jelly and agar, ice cream, and gravy and sauces all count, which matters for many local dishes such as herbal and soup-based meals, and for drinks like bubble tea, kopi and teh. Spreading your allowance across the day helps.
Managing thirst
Managing thirst makes the fluid limit far easier to keep. The single biggest help is reducing salt, which drives thirst. Other tips your team may suggest include using smaller cups, sipping rather than gulping, sucking ice chips or frozen fruit (counted within your allowance), sugar-free sweets or chewing gum, and rinsing your mouth without swallowing. If you have diabetes, keeping your blood sugar well controlled also reduces thirst. Small habits, used together, make a real difference.
Potassium
Potassium can build up between dialysis sessions, and a high level (hyperkalaemia) is dangerous because it can cause abnormal, potentially fatal heart rhythms. Whether and how much to limit high-potassium foods is decided by your renal dietitian from your blood results, so advice varies between people. Foods often high in potassium include potatoes, bananas, oranges and orange juice, tomatoes, avocado, dried fruit, nuts, beans and chocolate. Your dietitian may teach cooking methods, such as soaking and boiling potatoes, that lower potassium, and will set what is right for you.
Phosphate and binders
Phosphate also builds up on dialysis, and over time high phosphate weakens bones and contributes to calcium deposits in blood vessels. It is found in dairy, nuts and seeds, beans and lentils, offal, processed foods, and cola and dark fizzy drinks, which often contain phosphate additives. Phosphate is managed with both diet and phosphate binder medicines, which work in the gut to stop phosphate being absorbed. Because of how they work, binders are taken with meals and snacks as prescribed, never on an empty stomach and never skipped when eating out.
Salt and protein
Reducing salt helps in several ways: it lowers thirst, blood pressure and fluid retention. Cooking fresh and going easy on processed and preserved foods helps, and in local terms that means being cautious with soy, oyster and fish sauces, ikan bilis, salted and preserved foods, and instant-noodle seasoning. Be careful, too, with “low-salt” or salt substitutes, as many are high in potassium. Protein is different: because dialysis removes some protein, people on dialysis often need adequate or higher protein to prevent muscle loss, the opposite emphasis to many pre-dialysis diets. Our CKD diet guide covers the earlier stage, which differs.
The renal dietitian
The theme throughout is that everything is individual. Your blood tests for potassium, phosphate and nutrition guide adjustments over time, and your renal dietitian tailors advice to your remaining kidney function, your type of dialysis, your appetite, any diabetes, and your food culture, including local favourites. That is why this guide gives no gram limits: yours are set for you. In Singapore, ask your renal dietitian for advice built around the foods you actually eat, and charities such as NKF Singapore also offer nutrition guidance tailored to dialysis patients. Small, sustainable changes that fit around your usual meals tend to work far better in the long run than trying to overhaul your whole diet at once.
Related dialysis topics
- Living with dialysis
- Haemodialysis: what to expect
- Peritoneal dialysis: what to expect
- Home haemodialysis
- Access: fistula & catheter care
- Managing problems & when to get help
- Staying well & active
- Travelling & holidays
- Emotional wellbeing & daily life
- Kidney specialists in Singapore
Sources
- National Kidney Foundation – Potassium and your diet: kidney.org
- National Kidney Foundation – Phosphorus and your diet: kidney.org
- National Kidney Foundation – Nutrition and hemodialysis: kidney.org
- Kidney Care UK – Kidney Kitchen (renal diet): kidneycareuk.org
- British Dietetic Association – Food facts: bda.uk.com