Understanding IgG Food Tests for Food Sensitivities

IgG food sensitivity tests measure immunoglobulin G (IgG) antibodies that the immune system produces in response to certain foods. IgG is the most common type of antibody found in the blood and is part of the body’s normal immune response to everyday exposures, including foods.[1]

These tests are commonly used to help identify foods that may be associated with food sensitivities or digestive discomfort. People with food sensitivities may experience symptoms such as bloating, gas, stomach pain, diarrhea, fatigue, or headaches after eating certain foods. Unlike immediate reactions, food sensitivity symptoms can sometimes develop gradually or be harder to connect to a specific food.

Because IgG antibodies can develop after repeated exposure to foods, test results may help individuals recognize patterns between certain foods and their symptoms. Healthcare providers may use this information alongside symptom history, elimination diets, and other clinical factors to help guide dietary changes.

Testing for food sensitivities with an IgG test typically involves analyzing a blood sample to measure the body's immune response to certain foods [2]. In general, higher IgG levels after exposure to specific foods may indicate a greater likelihood of food sensitivity for that individual. While IgG food sensitivity tests are not always definitive, they can provide helpful insights when used alongside other clinical evaluation tools.

Once you receive your results, it's best to work with a qualified healthcare provider or nutrition professional to determine the next steps. Your care plan may include:

1. Reviewing your test results – A healthcare provider can help interpret which foods may be contributing to symptoms and determine whether additional evaluation is necessary.
2. Trying an elimination diet – An elimination diet involves temporarily removing potential trigger foods and gradually reintroducing them to monitor symptoms.
3. Considering follow-up testing – Depending on your symptoms, your provider may recommend additional testing to rule out food allergies, intolerances, or digestive conditions.
4. Monitoring symptom changes – Keeping a food and symptom journal can help identify patterns and determine whether dietary changes are improving digestive health and overall well-being.

There is mixed research surrounding IgG food sensitivity tests and their overall accuracy. In general, IgG tests may be more useful as informational tools rather than definitive diagnostic tools. They can provide additional insight into potential food sensitivities, but they should not be used alone to confirm a food-related diagnosis.

Here are a few important things to know about IgG testing:

• Elevated IgG levels can be normal – Some healthcare professionals believe IgG food tests should not be used diagnostically because healthy individuals naturally produce IgG antibodies after eating certain foods [3].
• A positive result does not always mean sensitivity – In many healthy people, elevated IgG levels are temporary and do not cause symptoms or health concerns. However, these antibodies may still appear elevated on a blood test.
• Symptoms matter most – If you are not experiencing symptoms after eating certain foods, it may not be necessary to eliminate those foods from your diet based solely on IgG results.
• IgG tests cannot diagnose food allergies – Diagnosing food allergies requires additional medical evaluation and testing methods beyond IgG testing alone [4].
• Major diet changes should be supervised – Eliminating multiple foods without guidance from a dietitian or qualified healthcare provider can increase the risk of unnecessary dietary restriction and nutrient deficiencies [4].
• Test quality can vary – Not all IgG tests are created equal. Choosing a reputable and well-vetted testing option is important to help ensure more reliable results.

Overall, IgG testing may serve as one piece of a broader wellness or nutrition plan, especially when combined with symptom tracking, professional guidance, and approaches like an elimination diet.

IgG food sensitivity tests use a blood sample to measure immunoglobulin G (IgG) antibody reactivity to specific foods. These tests typically include a wide variety of commonly consumed foods across categories such as dairy, grains, eggs, seafood, meats, fruits, vegetables, legumes, nuts, seeds, and spices.[5]

Everlywell offers two food sensitivity testing options: the Food Sensitivity Test, which measures IgG reactivity to 96 foods, and the Food Sensitivity Comprehensive Test, which measures IgG reactivity to 204 foods. Results classify each food on a scale from Class 0 (normal reactivity) to Class 3 (high reactivity). Foods with higher-than-normal IgG reactivity may be candidates to consider during an elimination diet designed to help identify foods associated with symptoms.

These tests are intended to provide information about IgG antibody reactivity and are not designed to diagnose food allergies, lactose intolerance, or celiac disease. A healthcare provider can help interpret results alongside symptoms, medical history, and dietary patterns.

Dealing with food sensitivities can be frustrating—especially when uncomfortable symptoms disrupt your daily life and the cause isn’t always clear. The good news is that you don’t have to navigate the process alone. While food sensitivity testing is not intended to diagnose a condition, it may help identify foods that could be contributing to your symptoms and provide a helpful starting point for an elimination diet or further discussion with your healthcare provider. If you’re ready to better understand how certain foods may relate to your symptoms, consider taking the Everlywell Food Sensitivity Test or the Everlywell Food Sensitivity Comprehensive Test.