The Myths of Food Sensitivity Tests: What You Need to Know

Introduction

In recent years, food sensitivity testing has exploded in popularity, fueled by promises to uncover “hidden food allergies” or hidden causes of fatigue, bloating, brain fog, skin issues, and more.

People who experience these symptoms are desperate for answers, but that makes them vulnerable to companies waiting to profit. The result? Patients end up frustrated, confused, and out hundreds or thousands of dollars.

These tests are marketed as “what your traditional doctor doesn’t know about.” But we do know about them — and when they are unvalidated and not backed by real science, we don’t recommend them. Scientists and clinicians increasingly warn that marketing and pseudoscience are misleading patients.

If you’re considering a food sensitivity test, here’s what you need to know.

Myth #1: Food Sensitivity Tests Accurately Identify Problem Foods

Reality: Most commercial tests measure IgG (Immunoglobulin G) antibodies. IgG reflects exposure, not intolerance or sensitivity.

• IgG is a normal immune response, not a sign of disease.
• In fact, during oral immunotherapy for real food allergies, IgG goes up as tolerance improves.
• Guidelines from the American Academy of Allergy, Asthma & Immunology (AAAAI) caution that IgG testing does not correlate with clinical symptoms.

Myth #2: IgG Results Can Replace an Elimination Diet

Reality: Elimination and reintroduction diets remain the gold standard for identifying food intolerances.

IgG tests often produce long “do not eat” lists, which:

• Restrict foods unnecessarily
• Risk nutritional deficiencies
• Increase anxiety around eating

All without improving symptoms.

Myth #3: Food Sensitivities Are the Same as Food Allergies or Intolerances

Reality: These are distinct conditions.

• Food allergies: IgE-mediated, can cause hives, anaphylaxis
• Food intolerances: Usually due to enzyme deficiencies (e.g., lactose intolerance), not immune-related
• Food sensitivities: Loosely defined, lacking universal criteria or validated tests

We need to use these terms correctly to avoid confusion.

Myth #4: A Long List of Reactive Foods Means You’re “Sensitive” to Everything

Reality: Reactivity on IgG panels often reflects foods you eat frequently, not true sensitivity.

Over-restriction based on such results can:

• Cause undue stress
• Trigger orthorexia-like behaviors (fear of “unsafe” foods)

If it feels like you’re reacting to everything, it’s time to stop blaming food alone. A professional evaluation can uncover root causes like gut imbalances or inflammatory conditions.

Myth #5: These Tests Are FDA-Approved for Diagnostic Use

Reality: Most direct-to-consumer tests are not FDA-approved for diagnosis. Even when labs are certified or tests are FDA-cleared, it doesn’t mean they’re clinically relevant.

Many use proprietary panels with little transparency, making results difficult to interpret for both practitioners and patients.

What to Do Instead

If you suspect food is impacting your health, try evidence-based steps:

• Work with a qualified allergist, immunologist, or dietitian
• Consider a structured elimination diet with supervision
• Evaluate gut health for issues like SIBO, histamine intolerance, or mast cell activation
• Rule out autoimmune conditions like celiac disease
• Consider non-immune causes such as enzyme deficiencies or FODMAP intolerance

The Bottom Line

Food sensitivity testing is a booming industry, but most available tests are not backed by strong science.

Relying on IgG testing alone can lead to misdiagnosis, nutritional harm, and expensive supplement upsells. It often ends up being a long, costly “quick fix” that doesn’t solve the problem.

The best path forward? An evidence-based, individualized approach that treats people — not lab reports.

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