Diet in chronic kidney disease: which foods are allowed and what to limit

Short answer: in chronic kidney disease (CKD, sometimes still called chronic renal insufficiency) there is no list of forbidden foods that applies to all patients. The basic rules are little salt (under 5 g a day), protein without excess and more fresh plant foods than meat and ultra-processed products, while potassium and phosphorus are limited when blood tests call for it. How strict the diet becomes depends on the stage of the disease, your test results and any other conditions you have, which is why the eating plan is set together with a nephrologist and, ideally, a nutritionist-dietitian.

• Salt matters at every stage: the international KDIGO 2024 guideline suggests less than 2 g of sodium a day, meaning less than 5 g of salt, in total.
• Protein: in stages G3-G5, without dialysis, the target is 0.8 g per kilogram of body weight per day, and more than 1.3 g/kg/day should be avoided. On dialysis, protein needs increase.
• Potassium is not restricted “just in case” for everyone: it is limited when it is or has been high, or during periods of high risk, and the first foods to cut are processed products, not fresh fruit and vegetables.
• Phosphorus from additives (phosphoric acid, phosphates) is absorbed almost completely, which is why cured meats and some soft drinks matter more than you might think.
• No food, tea or supplement “lowers creatinine” by repairing the kidneys, and some supplements can do harm.

There is no single diet for diseased kidneys, because chronic kidney disease has different stages. The stage is based on the estimated glomerular filtration rate (eGFR), usually calculated from blood creatinine: G1 (90 mL/min/1.73 m² or more), G2 (60-89), G3a (45-59), G3b (30-44), G4 (15-29) and G5 (under 15). Albuminuria, the loss of albumin in the urine, is measured separately. A patient in stage G2 with normal potassium does not have the same restrictions as someone in stage G4 or someone on dialysis. You can read more about the stages and causes in our article on chronic kidney disease (CKD).

That is why the international nephrology guideline KDIGO 2024 (Kidney Disease: Improving Global Outcomes) recommends that advice about salt, phosphorus, potassium and protein be adapted to each person’s needs, the stage of the disease and their other conditions, with the help of a dietitian or a nutrition specialist. Other conditions (for example diabetes), age and medication can also change the recommendations.

For most patients, the foundation is not a list of bans but a healthy, varied diet, with more plant foods than animal foods and fewer ultra-processed products, as the KDIGO 2024 guideline recommends. In practice, this means:

• fresh vegetables and fruit every day; if your potassium is high, your doctor will tell you which ones to prefer (see below);
• whole grains and legumes (beans, lentils, chickpeas) as sources of plant protein;
• fish, lean meat, eggs and dairy, in measured portions;
• herbs, salt-free spices, lemon juice or chili instead of salt;
• baked, grilled, braised or air-fried dishes instead of food fried in a lot of fat.

Mediterranean-style or DASH eating patterns, rich in vegetables, fruit and whole grains, have been associated in observational studies and small randomized trials with a slower decline in kidney function. At the other end, ultra-processed products (sweetened drinks, fast food, frozen ready meals, chips, sweets, pastries) bring a lot of salt, sugar and fat and little nutritional value.

Too much salt makes the body retain fluid and raises blood pressure. The KDIGO 2024 guideline suggests that people with chronic kidney disease take in less than 2 g of sodium a day, the equivalent of less than 5 g of salt, including the salt already present in foods. For comparison, average sodium intake worldwide is estimated at more than 4 g a day, more than twice as much. In randomized trials lasting up to 36 weeks, cutting salt lowered blood pressure and albuminuria in patients with CKD.

The target is hard to reach because salt is widely used in commercial products. Common sources are:

• cured meats and processed meat;
• canned foods and some frozen products;
• chips and salty crackers;
• ready-made sauces and condiments: ketchup, mustard, soy sauce, barbecue or teriyaki sauces, seasoning mixes with salt.

Labels may list either sodium or salt; as a guide, 2 g of sodium is about 5 g of salt. Be careful with “diet” salt and other salt substitutes: many contain potassium chloride, and the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and MedlinePlus, from the US National Library of Medicine, recommend avoiding them in chronic kidney disease. The KDIGO guideline lists them among sources of very easily absorbed potassium.

There are exceptions: in salt-losing kidney diseases, in malnutrition or in extreme heat, salt restriction may not be appropriate. These situations are assessed by the nephrologist.

Excess protein is not stored in the body: it is broken down, and the resulting waste products, such as urea, build up as kidney function declines. A high protein intake also raises the pressure in the glomeruli, the kidney’s tiny filters.

The KDIGO 2024 guideline suggests a protein intake of 0.8 g per kilogram of body weight per day for adults with chronic kidney disease in stages G3-G5 who are not on dialysis, and recommends avoiding a high intake, above 1.3 g/kg/day, in those at risk of progression. For comparison, adults in many countries eat on average about 1.2 g/kg/day.

Example: at 70 kg, 0.8 g/kg means about 56 g of protein a day. Grams of protein are not grams of food: 100 g of meat contains about 25 g of protein. Average values for common portions, according to the KDIGO guideline:

• meat, poultry, fish or seafood: 28 g provides 6-8 g of protein;
• one egg: 6-8 g;
• milk or yogurt: 250 mL provides 8-10 g;
• cheese: 28 g provides 6-8 g;
• cooked legumes (beans, lentils, chickpeas): 100 g provides 7-10 g;
• cooked whole grains: 100 g provides 3-6 g;
• starchy vegetables or bread: 2-4 g per portion.

The source matters too: the guideline recommends more plant foods and fewer animal foods. Less phosphorus and less potassium are absorbed from plant foods than from animal or processed foods, an advantage when these minerals need watching.

Less does not automatically mean better. A very low-protein diet (0.3-0.4 g/kg/day, supplemented with essential amino acids or ketoacid analogs) may be considered only for some patients at risk of kidney failure who are able to follow it, and only under close supervision. Low or very low-protein diets are not prescribed to people who are metabolically unstable. In frail older adults or people with low muscle mass, protein and calorie targets may even be higher, and in children with CKD protein is not restricted. On dialysis, protein needs increase, because dialysis removes protein from the blood.

Potassium is needed to keep the heart beating regularly, but when the kidneys no longer work well it can build up in the blood. The KDIGO 2024 guideline recommends an individual approach: limiting foods rich in easily absorbed potassium is advised for people in stages G3-G5 who have had high potassium, or during periods when the risk of a rise is high. The guideline also notes that medicines, metabolic acidosis, very high blood sugar or constipation explain high potassium more often than diet does, and that the lab value can vary with how the sample was taken and with treatment.

Many patient materials put fruit and vegetables at the top of the “forbidden” list. The KDIGO guideline shows, however, that potassium from fresh plant foods is absorbed to a lesser extent (about 50-60%) than potassium from animal foods (70-90%) and from potassium salts added to processed products (about 90%). Highly processed products, meat, dairy, fruit juices and salt substitutes with potassium chloride provide more absorbable potassium than many fresh fruits and vegetables. That is why processed products are the first to limit.

If your doctor has advised you to limit potassium, these pointers can help you choose (based on MedlinePlus):

• Fruit higher in potassium (limit): oranges and orange juice, nectarines, kiwi, bananas, cantaloupe, raisins and other dried fruit, prunes.
• Fruit lower in potassium (prefer): apples, pears, peaches, grapes, berries, pineapple, plums, tangerines, watermelon.
• Vegetables higher in potassium (limit): potatoes, tomatoes and tomato sauce, cooked spinach, asparagus, avocado, pumpkin.
• Vegetables lower in potassium (prefer): cabbage, cauliflower, broccoli, carrots, cucumbers, eggplant, peppers, onions, lettuce, celery, green beans, zucchini.

Two simple techniques: soaking some foods for 5-10 minutes in water that has first been brought to a boil can halve the potassium in some of them (KDIGO), and the liquid from canned fruit and vegetables should be drained and thrown away (NIDDK). If you have diabetes and need juice to treat low blood sugar, apple or grape juice contains less potassium than orange juice (NIDDK).

In advanced kidney disease, phosphorus can build up in the blood (hyperphosphatemia). The KDIGO guideline on mineral and bone disorders in CKD suggests limiting dietary phosphorus to treat hyperphosphatemia in patients in stages G3a-G5, including those on dialysis, and advises considering its source: animal, plant or additives.

The source matters because phosphorus is not absorbed in the same way: about 40-60% is absorbed from animal foods, usually 20-50% from plant foods (legumes, seeds), while phosphates added as additives are absorbed almost completely. Products with phosphate additives can contain almost 70% more phosphorus than those without.

• check the ingredient list for “phosphorus” or for terms such as phosphoric acid, disodium phosphate, monosodium phosphate;
• limit cured meats and flavored or soft drinks with added phosphates;
• dairy products are high in phosphorus: when phosphorus is high, their portions are reduced, as your doctor advises;
• choose fresh foods cooked at home instead of processed ones; fruit and vegetables are naturally low in phosphorus.

In the early stages of chronic kidney disease, you usually do not need to limit fluids. As the disease progresses, or after starting dialysis, the amount of fluid must be watched, because damaged kidneys can no longer remove the excess, and the limit is set individually by your doctor or dietitian. For general fluid needs and special situations, see diet and hydration for healthy kidneys.

The guideline targets, in brief. They are only a guide: the final recommendation takes into account your test results, other conditions and treatment.

• Stages G1-G2: salt under 5 g a day; protein without excess (avoid more than 1.3 g/kg/day if the disease is at risk of progressing); potassium and phosphorus usually without special restrictions; fluids are not limited in the early stages.
• Stages G3a-G3b: salt under 5 g a day; protein around 0.8 g/kg/day; potassium is limited if it is or has been high, and phosphorus if it is high.
• Stages G4-G5, without dialysis: salt under 5 g a day; protein 0.8 g/kg/day (a very low-protein diet only in selected cases, under supervision); potassium and phosphorus according to test results, with a plan made together with a nutritionist-dietitian; fluids may need to be limited.
• Dialysis: more protein than before dialysis; fluids are watched; salt, potassium and phosphorus are adjusted according to test results and the dialysis team’s advice.

There are no foods or teas that “lower creatinine” by repairing the kidneys. However, the creatinine value also depends on factors unrelated to kidney filtration, including muscle mass and diet. The KDIGO 2024 guideline notes that a meal with cooked meat or fish can temporarily raise creatinine: in one study by about 0.23 mg/dL, the equivalent of an eGFR about 20 mL/min/1.73 m² lower, with the greatest effect 2-4 hours after the meal. According to the guideline, a gap of at least 12 hours between a meal with meat or fish and the blood test best avoids this effect. High-protein diets and creatine supplements can also change creatinine.

In the long term, what protects the kidneys is controlled blood pressure and blood sugar, little salt, protein without excess and the treatment your doctor recommends. If your creatinine is high and you are not sure which doctor to see, read when you need a nephrology consultation.

Be careful with supplements and remedies “for the kidneys”. The KDIGO 2024 guideline recommends limiting over-the-counter medicines and herbal remedies or supplements that may be harmful in chronic kidney disease. Creatine supplements used in bodybuilding have been associated with allergic interstitial nephritis, and too much vitamin C can lead to calcium oxalate crystals depositing in the kidneys. Tell your doctor everything you take, including teas and supplements.

A good eating plan starts from your test results, not from a general list: eGFR and creatinine, albuminuria, potassium, phosphorus and the other values your doctor follows, plus your weight, eating habits and other conditions.

At NOVOMED CLINIC Constanța, the nephrology consultation with Dr. Dragoș Fășie, senior specialist in nephrology, establishes the stage of the disease, the risk and the treatment. To turn the recommendations into everyday meals, Gabriela Vișan, nutritionist-dietitian, offers nutrition consultations with a personalized eating plan, including for kidney disease, working together with the clinic’s doctors.

The KDIGO guideline recommends assessing nutritional status twice a year in people with CKD in stages G4-G5, in those over 65 and in those who lose weight without trying, are frail or have a poor appetite.

Which foods are forbidden in chronic kidney disease?

There are no foods forbidden for every patient. For most people, the things to limit are salt and ultra-processed products: cured meats, canned food, chips, sauces, ready meals. Foods rich in potassium or phosphorus are limited only when blood tests show it is necessary, as your doctor advises. Potassium-based salt substitutes and “kidney” supplements should not be used without your doctor’s approval.

Which fruits and vegetables are good for diseased kidneys?

If your potassium is normal, fresh fruit and vegetables are recommended as part of a more plant-based diet. If your doctor asks you to limit potassium, choose apples, pears, grapes, berries, pineapple, peaches, cabbage, cauliflower, cucumbers, peppers, eggplant or zucchini more often, and bananas, oranges, dried fruit, potatoes or tomatoes less often.

Are there foods that lower creatinine?

Not in the sense of repairing the kidneys. You can, however, avoid a falsely high result: do not eat a meal with meat or fish in the 12 hours before the test, and tell your doctor if you take creatine supplements or follow a high-protein diet.

What diet should you follow with a single kidney?

If the remaining kidney works normally, no special diet is needed: enough fluids, little salt and avoiding too much weight gain. If kidney function is reduced, the diet is adapted as in chronic kidney disease, based on test results.

What changes in the diet on dialysis?

Protein needs increase, because dialysis removes protein from the blood, and fluids must be watched. Potassium and phosphorus are adjusted according to test results. The exact amounts are set by the dialysis team.

Is “diet” salt a good alternative?

Not without your doctor’s approval. Many “diet” salt products contain potassium chloride, and in chronic kidney disease potassium can build up. For flavor, use herbs, salt-free spices, lemon juice or chili.

The diet in chronic kidney disease is not a long list of bans, but a few clear rules (little salt, protein without excess, more fresh plant foods and fewer processed products) plus adjustments based on test results. Restrictions on potassium, phosphorus and fluids make sense when they are needed; applied without need, they can make the diet less varied. The safest plan is one built on your own test results and reviewed regularly as the disease evolves.

If you have been diagnosed with chronic kidney disease or have abnormal creatinine or eGFR, you can book a nephrology and nutrition appointment at NOVOMED CLINIC (Str. Soveja nr. 78, Constanța) on WhatsApp (we reply in English), by phone at +40 724 007 799 (in Romanian) or with the online booking form. For prevention, if your kidneys are healthy, see also diet and hydration for healthy kidneys.

1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International, 2024;105(4S):S117-S314. kdigo.org
2. Kidney Disease: Improving Global Outcomes (KDIGO) CKD-MBD Update Work Group. KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Kidney International Supplements, 2017;7(1):1-59. kdigo.org
3. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Healthy Eating for Adults with Chronic Kidney Disease (reviewed January 2025). niddk.nih.gov
4. MedlinePlus, U.S. National Library of Medicine. Diet – chronic kidney disease (reviewed September 2, 2025). medlineplus.gov
5. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Solitary or Single-functioning Kidney (reviewed October 2020). niddk.nih.gov

This information is for general guidance only and does not replace a specialist consultation. For diagnosis and personalized treatment, see a nephrologist.