What is the best food sensitivity test that is not a scam?

Short answer: there isn’t a single “food sensitivity” test that reliably diagnoses non‑allergic food intolerances — but there are validated tests for specific problems. The safe, non‑scam approach is to use clinically proven tests for the condition you suspect and to work with a clinician/dietitian.

What actually works (and who provides it)

• Immediate (IgE) food allergy: see an allergist for skin‑prick testing and/or serum specific IgE testing. The ImmunoCAP system (Thermo Fisher) is the most widely used lab assay for specific IgE and is available through allergy clinics and major labs (Quest, LabCorp). These tests are appropriate if you have hives, wheeze, throat tightness, anaphylaxis, or reproducible immediate reactions.
• Celiac disease: get tissue transglutaminase IgA (tTG‑IgA) plus total IgA (and deamidated gliadin peptide if needed). These are standard blood tests offered by most clinical labs (Quest, LabCorp) and recommended by gastroenterology societies.
• Lactose/fructose malabsorption and SIBO: hydrogen (and methane) breath testing done in GI clinics is the validated test (clinics commonly use QuinTron or similar breath analyzers). These identify carbohydrate malabsorption or small intestinal bacterial overgrowth.
• Suspected non‑IgE, non‑celiac food intolerances (bloating, IBS‑type symptoms): the evidence supports an elimination diet (for example, a monitored low‑FODMAP elimination and reintroduction) supervised by a registered dietitian experienced in GI care. This diagnostic diet is the practical “gold standard” for many food‑triggered GI symptoms.

What to avoid or be skeptical about

• IgG food panels (commonly sold by Everlywell, Vibrant, YorkTest, many direct‑to‑consumer labs): major professional societies (American Academy of Allergy, Asthma & Immunology and gastroenterology groups) advise against using IgG testing to diagnose food intolerance or allergy. IgG antibodies mostly indicate exposure or even tolerance, not harmful sensitivity — they frequently produce misleading results and unnecessary dietary restriction.
• Broad “food sensitivity” panels sold direct‑to‑consumer with vague claims — these are often low clinical value.

Practical next steps

1. If you have acute allergic symptoms, see an allergist for skin testing or ImmunoCAP sIgE testing.
2. If you have chronic GI symptoms (bloating, diarrhea, weight loss), get evaluated by a GI doctor for celiac testing (tTG‑IgA) and consider breath testing for lactose/fructose/SIBO.
3. If symptoms are IBS‑like, consult a registered dietitian for a structured elimination diet (low‑FODMAP) rather than doing IgG testing.
4. If you’re tempted by a home IgG panel, discuss the results with a clinician and don’t make long‑term restrictive changes based on IgG alone.

If you tell me your main symptoms (immediate allergic reaction vs chronic GI problems vs skin symptoms), I can recommend the single best next test and specific clinics/labs in your area.