Kidney Disease Diet: Protein, Salt and Potassium Guide

A kidney disease diet for CKD stages 3 to 5 (not on dialysis) usually means a moderate amount of protein, about 0.6 to 0.8 g per kg of body weight a day, sodium around 2,000 mg, and controlled portions of meat and pulses. Potassium and phosphorus limits depend on your blood tests, so your kidney team sets them.

To get a starting meal plan that applies these limits to your weight and food habits, use the free kidney disease diet plan maker. It shows your protein limit and builds a 7-day plan with portions.

Important: kidney diets must be individual. This guide is general information. If you're on dialysis, pregnant, have diabetes too, or take potassium-affecting medicines, follow your nephrologist and renal dietitian.

Why does diet matter in kidney disease?

Damaged kidneys find it harder to remove waste from protein, extra salt, potassium, phosphorus and fluid. Eating the right amount of protein and less salt can ease the load and help control blood pressure, which protects the kidneys. The US National Institute of Diabetes and Digestive and Kidney Diseases describes these same steps.

How much protein should you eat?

For a 70 kg adult, 0.6 to 0.8 g per kg is roughly 42 to 56 g of protein a day. As a guide:

• 1 egg has about 6 g
• ½ cup cooked daal has about 9 g
• A palm-sized piece of chicken or fish (about 85 g) has about 20 to 25 g
• 1 cup of milk has about 8 g

Spread protein through the day, and don't use protein powders or supplements unless your kidney doctor approves.

How do you cut salt?

Aim for about 2,000 mg of sodium a day. Cook at home, use herbs, lemon and spices for flavour, and limit pickles (achar), papad, namkeen, processed meats, instant noodles, packet soups and fast food. Avoid salt substitutes unless your doctor says they're safe, because many are high in potassium.

When do potassium and phosphorus matter?

Only if your blood tests show high levels or your doctor tells you to limit them.

• High-potassium foods: bananas, oranges, potatoes, tomatoes, spinach, dried fruit, coconut water, some daals. Soaking and boiling vegetables and discarding the water (leaching) can lower potassium.
• High-phosphorus foods: processed cheese, cola drinks, processed meats, and foods with phosphate additives (look for "phos" on labels). Phosphorus from additives is absorbed much more than phosphorus in natural foods.

You can check your potassium, creatinine and eGFR with the kidney function test checker, then ask your doctor what they mean for your diet.

What can kidney patients eat?

Usually good choices: apples, pears, berries, grapes and pineapple; cabbage, cauliflower, bottle gourd (lauki), ridge gourd (tori), cucumber and capsicum; white rice and roti in normal portions (these are lower in phosphorus than whole grains); measured portions of chicken, fish, eggs or daal; olive, mustard or canola oil to add calories without protein.

Limit: large portions of meat, fish and pulses; dairy (milk, paneer, cheese) if phosphorus is high; high-potassium fruit and vegetables if potassium is high.

Avoid: very salty foods, cola drinks, processed and packaged foods with phosphate additives, herbal supplements and protein powders unless approved.

What does a sample kidney-friendly day look like?

For a 70 kg adult with CKD stage 3, not on dialysis, with normal potassium:

• Breakfast: 1 roti with a little oil, 1 egg or a small bowl of vegetable upma; tea with a small amount of milk, without sugar
• Mid-morning: an apple
• Lunch: 1 cup white rice or 2 roti, ½ cup daal, 1 cup lauki or tori sabzi, cucumber salad
• Snack: a few rice crackers or a pear
• Dinner: 2 roti, a small portion of chicken or fish curry (palm-sized), cabbage or cauliflower sabzi

If you have diabetes as well, carbohydrate portions need care too. Read the diabetes diet chart and ask your team to combine the advice.

What should be on the grocery list?

White or basmati rice, whole-wheat atta, eggs, chicken or fish in small amounts, daal, lauki, tori, cabbage, cauliflower, cucumber, capsicum, apples, pears and berries, olive or mustard oil, lemons, garlic, ginger and spices.

What mistakes should you avoid?

• Eating a lot of extra protein "for strength"
• Using salt substitutes without checking with your doctor
• Following potassium limits you don't need, which can make your diet unnecessarily poor
• Taking herbal remedies or painkillers like ibuprofen without advice

When should you contact your doctor?

Swelling in the legs or face, sudden weight gain, much less urine, breathlessness, muscle weakness, an irregular heartbeat or confusion need prompt medical attention.

Can kidney patients eat out?

Yes, with care. Choose grilled or plain dishes, ask for less salt and sauce, avoid cola and processed meats, and keep the protein portion small, about the size of your palm. If you have a potassium limit, choose rice over potatoes and skip tomato-heavy gravies.

What should you do next?

Read how to choose a diet for your health condition if you have more than one condition. Then make a starting plan with the kidney disease diet plan maker and take it to your renal dietitian.