Food Intolerance Tests UK 2026 — What Actually Works, What Doesn't

Three related but distinct things:

Food allergy: immune system reaction (IgE antibodies), can be severe, potentially life-threatening (anaphylaxis). Diagnosed by NHS allergy clinic via skin-prick or blood test. Requires medical management. Common: peanut, tree nuts, milk, egg, shellfish, wheat, soy.

Food intolerance: non-immune adverse reaction, usually digestive (bloating, discomfort, gas). Not life-threatening. Diagnosed usually by elimination diet + reintroduction. Common: lactose (milk), FODMAP compounds (onion, garlic, wheat), histamine (fermented foods, aged cheese, wine).

Food sensitivity: the loosest term, no agreed medical definition. Sometimes used for delayed IgG-mediated responses (which have questionable clinical significance) or for subjective adverse reactions without a clear mechanism.

The important distinction: allergy testing is medically standardised. Intolerance testing is not — no single test is definitively diagnostic, and the gold standard remains elimination + reintroduction under supervision.

1. Elimination diet (gold standard, free): remove suspected food group for 4-6 weeks, reintroduce, track symptoms. NHS-recommended, most reliable, cheapest. Downside: slow (12+ weeks for multiple food groups) and requires food diary discipline.

2. NHS / private allergy blood test (medically validated): IgE-based blood test done at GP referral or private allergy clinic. Diagnostic for allergy (not intolerance). Cost NHS-free with referral; £150-£400 privately. What it detects: true food allergies. Limitations: does not detect intolerance.

3. At-home intolerance tests (screening only): hair-strand bioresonance (Check My Body Health, YorkTest), IgG-based blood test kits, or breath tests (for lactose, fructose). Cost £45-£200. What they detect: signals that MAY correlate with intolerance. Limitations: bioresonance and IgG tests are not clinically diagnostic — they should be treated as starting points for a supervised elimination diet, not conclusive answers.

Check My Body Health runs hair-strand bioresonance testing — you send in a hair sample, they run it through a bioresonance machine that measures energy-frequency variations claimed to correlate with 800+ food and non-food items. Digital results in 5-7 days.

What CMBH is: a screening tool that produces a list of items showing "intolerance indication" at various severity levels. £45-£95 depending on scope (food only, food + environmental, food + environmental + vitamin deficiency).

What CMBH is not: a clinical diagnostic. Bioresonance is not recognised by the NHS or the British Dietetic Association as a validated intolerance-detection method. Results should be treated as hypothesis-generating for a supervised elimination diet, not as definitive answers.

Where CMBH is genuinely useful: as a low-cost starting point when you have vague digestive symptoms and no idea where to start. The itemised list gives you specific candidates to eliminate + reintroduce systematically, which is faster than open-ended elimination diet.

Where CMBH is misleading: if the list is treated as a permanent no-eat list. Removing 20 foods for 6 months based on a bioresonance test can create real nutritional deficits + disordered eating patterns. Always work through the list systematically via elimination + reintroduction, ideally with GP or dietitian oversight.

YorkTest (£125-£299): IgG-based blood test measuring IgG antibody response to 100-200 foods. UKAS-accredited lab. IgG testing has real scientific basis but disputed clinical relevance — the British Society for Allergy and Clinical Immunology (BSACI) does not recommend IgG testing for intolerance diagnosis, citing insufficient evidence that IgG antibodies correlate with symptoms.

Lorisian (£95-£199): similar IgG methodology. Same evidence-base concerns.

How to use IgG panels responsibly: as a hypothesis-generator for an elimination diet, exactly as with bioresonance. Don't remove 15 foods for life based on IgG alone.

Hydrogen breath tests are properly clinical for two specific intolerances:

Lactose breath test: drink measured lactose, breath tested at intervals for hydrogen. Elevated hydrogen = lactose fermented by gut bacteria = lactose intolerance. Gold standard for lactose intolerance. NHS-available with GP referral; £80-£150 privately.

Fructose / SIBO breath test: similar methodology for fructose malabsorption or small intestinal bacterial overgrowth. NHS-available with referral; £120-£200 privately.

If you strongly suspect lactose or fructose specifically, a breath test is dramatically more useful than a general bioresonance or IgG panel.

Worth doing:

• You have vague digestive symptoms (bloating, gas, discomfort) for 3+ months and no clear cause
• You've tried a general elimination diet without a clear pattern emerging
• You want a starting shortlist of foods to eliminate + reintroduce systematically
• Your budget for investigation is £50-£150 and you're not close to NHS-referral criteria

Not worth doing:

• Symptoms suggest allergy (hives, throat tightness, breathing difficulty) — see GP for allergy referral
• Symptoms are severe or worsening — see GP, don't self-investigate
• You have known conditions (IBD, coeliac, IBS diagnosed) — work with your gastroenterologist, not with a screening test
• You're planning to eliminate 5+ foods based on results without medical oversight — this creates nutritional risks

The evidence-based method for identifying food intolerance:

1. Baseline symptom diary for 2 weeks — record symptoms daily on a 1-10 scale, note foods eaten
2. Elimination phase (4-6 weeks): remove the suspected food group entirely. Common eliminations: dairy, wheat, eggs, soy, high-FODMAP foods. Bioresonance/IgG results can inform the shortlist.
3. Reintroduction phase (2 weeks per food): reintroduce one food at a time, in increasing quantities over 2-3 days, monitoring symptoms.
4. Confirmation: if a symptom recurs on reintroduction, remove that food, wait 2 weeks, reintroduce again. Two positive challenges = likely intolerance.

Total time for a 4-food investigation: 12-18 weeks. Slow, but produces reliable answers vs test-only approaches.

Use Random 30-Minute Dinner, Random Cuisine Picker, and Food Wheel for meal planning during and after elimination.

Cross-references: best UK meal kits for eliminating specific ingredients easily (HelloFresh and Gousto both offer dairy-free / gluten-free menus), HelloFresh vs Gousto for meal-kit choice, and teeth whitening for the other end of the self-care spectrum.

Symptoms suggest allergy: GP → NHS allergy clinic. Do not use at-home screening.

Vague digestive symptoms, 3+ months, no starting point: Check My Body Health (£45-£95) as a hypothesis-generator, then systematic elimination + reintroduction of the highest-severity indicators.

Suspect lactose or fructose specifically: hydrogen breath test (NHS-referral or £120-£200 privately). Directly diagnostic.

Want the definitive answer: full elimination diet under NHS dietitian or private dietitian supervision. £300-£800 for structured programme, 12-18 weeks, most reliable.

What NOT to do: remove 15 foods permanently based on a single at-home test result. This creates nutritional deficits and disordered eating patterns without solving the underlying question.