Kidney Diet 7 min read·Updated 22 July 2026 Clinician-reviewed

Is Feta Bad for Your Kidneys?

A UK Consultant Nephrologist on feta in chronic kidney disease — a flavourful brined cheese that needs small portions and a quick rinse to fit a renal diet.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 22 July 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

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Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

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Direct answer

Feta is high in sodium (~ 2.5–3 g salt per 100 g). Small 30 g portions, rinsed under cold water, can fit a CKD diet 1–2 × per week. The phosphate is moderate; salt is the main issue.

Key recommendation: Per 100 g: ~ 14 g protein, ~ 340 mg P, ~ 2.5–3 g salt.

Quick answer

✓ Best choices

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

✓ Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Key takeaway

Feta is high in sodium (~ 2.5–3 g salt per 100 g). Small 30 g portions, rinsed under cold water, can fit a CKD diet 1–2 × per week. The phosphate is moderate; salt is the main issue.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Is Feta Bad for Your Kidneys?

The brine problem

Traditional Greek feta is brined for weeks to develop flavour and preserve shelf life. The brine drives sodium into the cheese matrix; UK supermarket feta (Tesco, Sainsbury's, President) all run 2.5–3 g salt per 100 g. This is among the saltiest mainstream cheeses on the market.

Salt-reduction technique

Crumble the portion you'll use into a sieve, rinse under cold tap water for 30 seconds, and pat dry with kitchen paper. This removes ~ 20–30% of surface sodium without ruining flavour. Combine with no added salt in the rest of the dish.

Practical CKD-friendly ideas

  • Greek salad: 30 g rinsed feta + cucumber + tomato + red onion + olive oil + oregano. No added salt.
  • Watermelon and feta salad (low-K fruit base) — small 20 g crumble.
  • Roasted pepper and feta tart on a homemade low-salt pastry — count the feta as a salt portion.
  • Avoid: feta-stuffed olives (double sodium), spanakopita (filo + feta + salt), 'feta and spinach' ready meals.
Is Halloumi Bad for Your Kidneys?
Related reading: Is Halloumi Bad for Your Kidneys?.

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Read labels: sodium ≤ 0.3 g per 100 g (low) is the target
  • Cook from scratch when you can — it controls the hidden salt and phosphate
  • Personalise potassium and phosphate targets with your renal dietitian

Clinical guidance

TL;DR summary

Feta is high in sodium (~ 2.5–3 g salt per 100 g). Small 30 g portions, rinsed under cold water, can fit a CKD diet 1–2 × per week. The phosphate is moderate; salt is the main issue.

Key takeaways
  • Per 100 g: ~ 14 g protein, ~ 340 mg P, ~ 2.5–3 g salt.
  • 30 g crumble = ~ 0.8 g salt — significant on a renal diet.
  • Rinse under cold water to drop sodium 20–30%.
  • Portion: 30 g, 1–2 × per week.
  • Avoid 'marinated feta' in oil with herbs and salt.
Kidney Diet & Nutrition Considerations

On a kidney-friendly diet, single foods matter less than the overall pattern. Build meals around vegetables, lower-potassium fruit, whole grains, sensible protein and olive oil, and watch the three usual suspects — salt, phosphate additives and oversized portions of very high-potassium foods. Targets are individual and should be confirmed with your renal team.

Foods to prioritise

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

Is feta bad for kidneys?

Feta is brined — typically 2.5–3 g salt per 100 g, among the saltiest cheeses on UK shelves. A 30 g crumble is ~ 0.8 g salt — over 13% of the daily 6 g limit. Small portions and rinsing reduce the load.

Is feta high in phosphate?

Per 100 g: ~ 340 mg P — comparable to mozzarella. The phosphate is natural dairy P (40–60% absorbed), much less concerning than the sodium.

Does rinsing feta reduce salt?

Yes — rinsing crumbled feta under cold water for 30 seconds, then patting dry, can reduce surface sodium by 20–30%. Useful if you want to keep feta in your diet on a low-salt CKD plan.

How much feta can I eat with CKD?

Stage 1–3: 30 g (small crumble), 1–2 × per week. Stage 4–5: 20 g, occasional. Always factor in your other sodium sources that day.

What foods are best for kidney health?

A kidney-friendly diet centres on vegetables, lower-potassium fruit (apples, pears, berries), whole grains (oats, basmati rice, pasta), sensible portions of fish, eggs or lean meat, beans and lentils in modest portions, and olive oil as the main cooking fat — broadly a Mediterranean pattern with reduced salt.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK renal guidance

Aligned with NICE NG203, KDOQI 2020 and BDA renal nutrition guidance.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Evidence-based by design

No added potassium or phosphate; sensible vitamin doses.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • No Added Potassium
  • No Added Phosphorus
  • No Added Iron
  • UK Manufactured
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
Subscribe & Save — £20.39/monthCheck your current multivitamin

✓ Free UK tracked delivery  ·  ✓ Delivered every 30 days  ·  ✓ Pause or cancel anytime  ·  ✓ Never run out

ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

View professional profile →
View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

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