Kidney Diet 8 min read·Updated 21 October 2026 Clinician-reviewed

Is Soup Bad for Your Kidneys?

A UK Consultant Nephrologist on tinned, packet and fresh soup in chronic kidney disease — and how to build a renal-friendly bowl.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 21 October 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

Most ready-made soups are sodium bombs (1,200–2,000 mg per tin) and tomato-based versions stack high potassium too. Homemade soup with no-added-salt stock, renal-friendly vegetables (carrot, leek, courgette) and herbs is the safest option.

Key recommendation: A 400 g tin of soup: 1,200–2,000 mg sodium typically.

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

Most ready-made soups are sodium bombs (1,200–2,000 mg per tin) and tomato-based versions stack high potassium too. Homemade soup with no-added-salt stock, renal-friendly vegetables (carrot, leek, courgette) and herbs is the safest option.

Who should be cautious

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

Is Soup Bad for Your Kidneys?

The sodium reality of tinned soup

UK supermarket tinned soups average 0.5–1.0 g salt per 100 g. A standard 400 g tin = 2.0–4.0 g salt = 800–1,600 mg sodium. 'Cream of' varieties (cream of tomato, cream of chicken) are at the higher end. For CKD with hypertension or fluid restriction, a single tin can exceed two-thirds of the daily sodium budget.

Hidden potassium in 'healthy' soups

Tomato-based soups concentrate potassium because passata uses 5–6 fresh tomatoes per 100 ml. Lentil, bean and chickpea soups deliver 400–600 mg potassium plus 200–300 mg phosphate per portion. 'Country vegetable' and minestrone with beans can also be high. Read the back-of-pack table.

Stock cubes and bouillon

Standard stock cubes (Oxo, Knorr, Maggi) are essentially compressed salt. Even 'reduced salt' versions deliver 400–600 mg sodium. Many 'low-sodium' bouillons substitute potassium chloride (KCl), which is dangerous in CKD 4–5 and on dialysis. Use Marigold no-salt vegetable bouillon, herbs, garlic, lemon, smoked paprika and freshly cracked pepper instead.

A renal-friendly homemade soup template

Base: 1 small onion + 1 leek + 2 carrots + 1 courgette, sautéed in olive oil. Stock: 500 ml hot water + 1 tsp Marigold no-salt bouillon. Flavour: 1 bay leaf, ½ tsp thyme, ½ tsp smoked paprika, black pepper, juice of ½ lemon. Protein (optional): 50 g shredded poached chicken. Avoid: tomato passata bases, lentils/beans in large amounts, ready-made stock cubes, instant cup-a-soups (very high sodium).

Food first. If you are choosing a daily multivitamin alongside a balanced diet, Kidney Vitality was developed by a UK Consultant Nephrologist using renal nutrition principles. See the formulation.

Is Salt Bad for Your Kidneys?
Related reading: Is Salt 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

Most ready-made soups are sodium bombs (1,200–2,000 mg per tin) and tomato-based versions stack high potassium too. Homemade soup with no-added-salt stock, renal-friendly vegetables (carrot, leek, courgette) and herbs is the safest option.

Key takeaways
  • A 400 g tin of soup: 1,200–2,000 mg sodium typically.
  • Tomato soup: 700–900 mg potassium per tin.
  • Stock cubes contribute ~ 700–1,000 mg sodium each.
  • Lentil/pulse soups stack potassium and phosphate — limit in advanced CKD.
  • Homemade with no-salt stock + carrots, leeks, courgette = renal-friendly.
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 soup bad for kidneys?

Tinned and packet soups are usually very high in sodium — a single 400 g tin can contain 1,200–2,000 mg sodium (half the daily NHS limit). Homemade soup with no-salt stock and renal-friendly vegetables is a much safer option.

Which tinned soups are lowest in salt?

Look for soups labelled 'reduced salt' or 'low salt' with a green traffic light for salt (< 0.3 g/100 ml). Even then, the full tin can deliver 600–900 mg sodium. Half-tin portions and pairing with low-salt bread are sensible.

Are stock cubes bad for kidneys?

Yes — one Oxo or Knorr stock cube contains ~ 700–1,000 mg sodium. They also often contain potassium chloride and monosodium glutamate. Use no-added-salt stock pots, herbs, garlic and lemon for flavour instead.

Is tomato or vegetable soup high in potassium?

Tomato soup is the highest — a 400 g tin can deliver 700–900 mg potassium. Vegetable soups vary by ingredients; soups with potatoes, leeks, beans or tomato will be higher. Lentil and pulse soups stack both potassium and phosphate.

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.

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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, KDIGO 2024 and BDA renal nutrition guidance on sodium and potassium.

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.

Compare formulation principles
ComparisonKidney VitalityTypical high-street multivitamin
Added potassium / magnesium / phosphorusNoneVaries — check label
FormulationNamed UK Consultant NephrologistVaries by manufacturer
ManufacturingUK facility: BRCGS / NSF GMPCheck facility certification

Other products vary. Compare their full labels and doses with your clinician; certification is not evidence of clinical efficacy.

Recommended next

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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