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

Short answer: There isn’t a single, validated “food sensitivity” blood test that reliably diagnoses food intolerance. Many commercial IgG panels (the ones marketed as “food sensitivity” tests) are not evidence‑based and are actively discouraged by allergy and immunology societies. Instead, use targeted, evidence‑based tests matched to the specific problem you suspect.

What’s reliable (and the brands/services to use)

• IgE‑mediated food allergy (immediate, hives/aphylaxis/angioedema/respiratory): skin prick testing by a board‑certified allergist or serum specific IgE testing by ImmunoCAP (Thermo Fisher/Phadia), which is the standard lab assay used by major labs (Quest Diagnostics, LabCorp). These tests are clinically useful when interpreted with your history by an allergist.
• Celiac disease (autoimmune reaction to gluten): tissue transglutaminase IgA (tTG‑IgA) plus total IgA, usually run by major clinical labs (Quest, LabCorp, Mayo Clinic Labs). This panel is well validated.
• Lactose intolerance and carbohydrate malabsorption: hydrogen breath test performed by gastroenterology clinics and some diagnostic labs (GI clinics/hospital labs). This is the accepted test for lactose malabsorption.
• SIBO (small intestinal bacterial overgrowth): hydrogen/methane breath testing at reputable GI clinics (use an experienced gastroenterologist; tests have limitations but are established in practice).
• Peanut/other high‑risk allergies: component testing (e.g., Ara h 2 for peanut) via ImmunoCAP can help assess risk more accurately than whole‑extract IgE alone.
• Non‑IgE adverse food reactions or functional GI symptoms (IBS): there is no reliable single lab test. An evidence‑based approach is an elimination diet (e.g., low‑FODMAP) supervised by a registered dietitian (look for an RDN with IBS/FODMAP experience, e.g., members of the Academy of Nutrition and Dietetics, or RDNs at centers such as the Mayo Clinic).

What to avoid

• IgG (or IgG4) “food sensitivity” panels sold direct‑to‑consumer or through some clinics (examples: Everlywell Food Sensitivity Test, Vibrant America/Vibrant Wellness panels and similar). Major professional societies (AAAAI, EAACI, BSACI) say IgG testing does not identify clinically relevant food intolerance and can lead to unnecessary restrictive diets and nutritional risk.

Practical plan

1. Identify the pattern: immediate allergic symptoms (hives, throat closing, anaphylaxis) vs delayed GI‑predominant symptoms vs bloating/IBS-type symptoms.
2. If allergic history → see an allergist for skin testing and/or ImmunoCAP and management.
3. If celiac is possible (diarrhea, weight loss, family history) → get tTG‑IgA and total IgA before trying gluten‑free diet.
4. If lactose or carbohydrate intolerance suspected → discuss hydrogen breath testing with GI.
5. If functional GI/possible food triggers but no allergy or celiac → work with a registered dietitian for a medically supervised elimination/rechallenge (this is often the most practical, evidence‑based route).
6. Avoid buying IgG food panels; if you already have one, take the results to your clinician but don’t rely on them alone.

If you want, tell me your main symptoms and I’ll recommend the most appropriate test and a next step (e.g., find an allergist, request specific labs, or set up a dietitian‑supervised elimination).