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

Short answer: avoid commercial “IgG food sensitivity” panels (they’re not evidence‑based). For reliable, clinically useful testing, use one of these depending on your symptoms:

1. For suspected food allergy (immediate hives, swelling, throat tightness, anaphylaxis)

• See an allergist. Tests: in‑office skin‑prick testing and/or serum specific IgE testing (ImmunoCAP by Thermo Fisher is the widely used lab method; major labs like Quest Diagnostics and LabCorp run these). If needed, the allergist may do a supervised oral food challenge (the diagnostic gold standard). Why: validated by allergy societies and useful for IgE‑mediated reactions.

1. For suspected celiac disease (diarrhea, weight loss, iron deficiency, family history)

• Get celiac serology: tissue transglutaminase IgA (tTG‑IgA) plus total IgA (Labs: Quest, LabCorp, hospital labs). Why: well‑validated blood tests; positive results should be followed by GI referral/biopsy per guidelines.

1. For suspected carbohydrate malabsorption (bloating, gas, diarrhea after milk or fruit)

• Hydrogen/methane breath testing (lactose or fructose breath tests) performed by GI clinics or testing centers; devices commonly used include QuinTron systems. Why: established, physiologic test for lactose/fructose malabsorption and SIBO.

1. For chronic GI symptoms without clear allergy or celiac

• Do a supervised elimination/rechallenge (low‑FODMAP approach for IBS) with a registered dietitian. Monash University’s low FODMAP resources and app are standard references. Why: elimination diets under guidance are the most practical, evidence‑based way to identify triggers for functional GI symptoms.

What to avoid

• IgG “food sensitivity” panels sold direct‑to‑consumer (examples: Everlywell, Vibrant Wellness, YorkTest and similar broad IgG/food intolerance panels). Professional allergy and gastroenterology societies say IgG levels usually reflect exposure/tolerance, not harmful immune reactions, and using them leads to unnecessary and restrictive diets.

If you tell me your main symptoms (immediate allergy vs chronic GI vs family history of celiac), I can recommend the single best next test and how to get it locally.