What a Food Sensitivity Report Actually Looks Like

You've probably seen ads for food sensitivity tests. A blood draw or saliva sample, a few weeks of waiting, and then a report arrives - sometimes dozens of pages long, listing foods you're "sensitive" to with accompanying charts and severity ratings.

These reports look authoritative. They're often expensive. And they're frequently misleading.

I want to walk through the different types of food sensitivity reports that exist - what they contain, what the results actually mean, and how to read them without being misled.

Type 1: IgG food sensitivity blood tests

This is the most common type of commercial food sensitivity test. Companies like YorkTest, Everlywell, and many others offer panels testing for IgG antibodies against 50-200+ foods.

What it actually shows

IgG antibodies indicate exposure. When you eat a food regularly, your immune system produces IgG antibodies against proteins in that food. This is a normal immune response - not evidence of sensitivity or intolerance.

A "positive" result for wheat on an IgG test means you eat wheat regularly and your immune system has noticed. It does not mean wheat is causing your symptoms.

What the report looks like

These reports typically show a bar chart or grid with each tested food and a result ranging from "normal" to "elevated" or similar. Foods are often color-coded (green = fine, yellow = consider reducing, red = avoid). The visual presentation implies clinical precision that the underlying science doesn't support.

What to do with it

If you've already had one of these tests, don't panic - but do not use its colour bands or rankings to decide what to eliminate. If your symptom history independently points to a particular food, discuss that pattern with a qualified professional and test the hypothesis using an appropriate clinical or structured dietary pathway.

Type 2: Allergy (IgE) testing

This is medically validated and used by allergists. It tests for IgE antibodies - the immune response involved in true food allergies.

What it shows

Skin prick tests or specific IgE blood tests (RAST tests) identify which food proteins your immune system has developed a rapid allergic response to. A positive result means there's a risk of an allergic reaction to that food.

What the report looks like

These come from labs or allergy clinics and show specific IgE levels in kU/L (kilounits per liter) for each tested food, along with reference ranges. The numbers require clinical interpretation alongside your symptom history.

Type 3: Breath tests for specific intolerances

Hydrogen breath tests are the validated clinical tool for diagnosing lactose intolerance, fructose malabsorption, and small intestinal bacterial overgrowth (SIBO).

How they work

You consume a test substance (lactose, fructose, or lactulose), and hydrogen levels in your breath are measured at intervals over 2-3 hours. Elevated hydrogen indicates fermentation in the gut - meaning the substance is reaching the large intestine unabsorbed (lactose/fructose) or there are bacteria fermenting in the small intestine (SIBO).

What the report looks like

A graph showing breath hydrogen levels over time, with baseline and peak readings. Results are interpreted as positive or negative based on how much hydrogen is produced and when the peak occurs.

This test is actually meaningful - it directly measures a physiological process rather than an immune marker.

Type 4: Elimination diet tracking and analysis report

This is the type I find most practically useful for IBS - not because it looks most authoritative, but because it's based on your actual response to specific foods rather than a proxy marker.

What it looks like

A report generated from 4-6 weeks of tracking data typically contains:

• A summary of your baseline symptom frequency and severity
• A ranked list of foods or food groups that correlate with high-symptom days
• A list of foods that appear consistently on low-symptom days (potentially "safe" foods)
• Any identified stress/mood correlations with symptoms
• Suggested priority foods to test through elimination
• Timeline of symptom patterns (time of day, day of week, etc.)

This type of report is typically generated by AI analysis of your tracking data, combined with structured elimination testing results over the following months.

How to read any food sensitivity report critically

Regardless of the type of report you're looking at, ask these questions:

• What is actually being measured? (IgG, IgE, breath hydrogen, symptom correlation?)
• Is this measurement validated as a diagnostic tool for food sensitivity?
• Does the report explain the methodology, or just show results?
• Are the results probabilistic or definitive?
• Does the report recommend follow-up clinical testing or elimination confirmation?
• Is the company selling the test also selling the supplements/diet plan to fix the results?

A practical pathway for suspected digestive triggers

There is no single test or pathway for every food reaction. Allergy, coeliac disease, lactose or fructose malabsorption, and other conditions may require specific clinical tests. For suspected non-allergic digestive triggers, a clinician or registered dietitian may suggest a structured trial such as:

1. Elimination (remove suspected food completely for 2-3 weeks)
2. Symptom tracking during removal
3. Reintroduction challenge (reintroduce and monitor for 48-72 hours)

This is less exciting than a detailed report with colour-coded charts, and it takes longer. It can help test whether a suspected food is repeatedly associated with symptoms, but it does not replace allergy testing or condition-specific clinical assessment.

Keep reading

Food Sensitivity vs Food Allergy: What's the Difference? These terms get used interchangeably, but they mean very different things.

How to Do an Elimination Diet Without Losing Your Mind Elimination diets work - but they're easy to do wrong. Here's a practical, sane guide.

8 Common Food Triggers for IBS (And How to Test Them) Not all IBS triggers are the same. Here are 8 of the most common food culprits.

Written by Kesava

I've lived with IBS since 2018 and saw four gastroenterologists before I started tracking properly. Find My Triggers is what I wish I'd had from the start.

This article is for informational purposes and is not medical advice. Talk to your doctor before making dietary changes.