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

Short answer: there is no single reliable consumer “food sensitivity” test sold direct-to-consumer. The only evidence‑based testing depends on what problem you actually have — immediate (IgE) food allergy, celiac disease, or an intolerance — and should be done by a clinician using validated assays and/or supervised food challenge.

What to use, by problem (with brand/lab names):

• Suspected immediate (IgE) food allergy (hives, swelling, anaphylaxis, wheeze, vomiting soon after eating)

  • Best approach: evaluation by a board‑certified allergist who will do skin prick testing and/or serum specific IgE testing and, if needed, a supervised oral food challenge (the gold standard).
  • Serum test: ImmunoCAP (Thermo Fisher/Phadia) is the widely used, validated sIgE assay used by major labs (Quest Diagnostics, LabCorp, ARUP). These are clinically meaningful when interpreted by an allergist.

• Suspected celiac disease (diarrhea, weight loss, anemia, etc., or family history)

  • Best tests: tissue transglutaminase IgA (tTG‑IgA) plus total IgA; if IgA deficient, deamidated gliadin peptide (DGP) IgG.
  • Reputable labs: Quest Diagnostics, LabCorp, ARUP — ask for standard tTG/DGP assays. Don’t start a gluten‑free diet before testing.

• Suspected carbohydrate intolerance (lactose, fructose, small intestinal bacterial overgrowth)

  • Best test: hydrogen (and methane) breath test, performed by a GI clinic using clinical equipment (QuinTron is a commonly used clinical system). Some reliable GI labs/centers do these in‑clinic.

• Non‑celiac gluten sensitivity, histamine intolerance, or vague “food sensitivity”

  • There is no validated laboratory test. Diagnosis is by careful elimination diet and symptom re‑challenge under medical/dietitian supervision.

What to avoid (scams or low‑value tests)

• IgG or IgG4 food panels sold direct‑to‑consumer (Everlywell, YorkTest, Pinnertest, many others) or proprietary tests such as ALCAT, Mediator Release Test (MRT)/LEAP are not supported by allergy and gastroenterology societies for diagnosing food intolerance or sensitivity. IgG often simply reflects exposure and does not predict harmful reactions — acting on these results can lead to unnecessary and nutritionally harmful diets.

Practical recommendation

• If you have concerning symptoms (hives, breathing problems, GI distress, weight loss, anemia), see an allergist or gastroenterologist. Ask for ImmunoCAP/skin testing for allergy, tTG/DGP for celiac, or a clinician‑supervised hydrogen breath test for suspected lactose/SIBO issues.
• If you want, tell me your symptoms and I can recommend the most appropriate test and how to find a local specialist or lab.