A Detailed Breakdown of How Food Intolerance Tests Work - Test Your Intolerance

What is the science behind food intolerance testing?

When you eat, your digested food should leave the digestive system via one of two channels – ideally as a bowel movement or, less desirably, vomiting. Problems with this could mean an intolerance is present, meaning an intolerance test is on the cards.

If you have intestinal hyperpermeability or leaky gut, some of the food you eat may leak out of your intestine and enter your blood circulation where it doesn’t belong. Your immune system considers this foreign body in your bloodstream to be a potentially harmful antigen and produces IgG antibodies specific to that potentially harmful antigen. The IgG antibodies then bind to the potentially harmful antigen to form an antigen-antibody complex. The formation of these complexes triggers inflammatory reactions throughout your body, causing food intolerance symptoms due to your immune system’s heightened response to the presence of antigens outside of your intestine, exacerbating inflammation and potentially leading to discomfort or adverse reactions.

What does a food intolerance test look for?

Food intolerance tests look for proteins in your blood called immunoglobulin-G or IgG antibodies. This is different from an allergy test, which looks for IgE antibodies in your blood. Healthy Stuff intolerance tests only look at type 4 IgG antibodies, known as IgG4 – these specific antibodies have been associated with the development of intolerance symptoms in scientific research papers.

What are the symptoms of a food intolerance?

An IgG-mediated food intolerance may present with a myriad of symptoms, ranging from skin rashes and urticaria to gastrointestinal issues, including IBS, abdominal cramps, diarrhoea, and constipation. Migraines have been linked to food intolerances, as have some respiratory issues such as asthma and rhinitis. Food intolerance symptoms may appear as quickly as 30 minutes after consumption of a trigger item, but more often, they develop several hours or even days later.

Are there different types of food intolerance tests?

A food intolerance test that identifies and measures IgG antibodies is achieved through an ELISA (enzyme-linked immunosorbent assay) blood test. This may be done as a blood draw from your vein (e.g. from a vein in your arm or the back of your hand) or from a finger-prick blood sample that you can take yourself. Bioresonance, quantum energy, and other such devices may be marketed for identifying food intolerances, but these will be looking at what is stressing the energy of the body rather than measuring the IgG antibodies being produced and are therefore not considered IgG food intolerance tests.

Likewise, a skin-prick test, where items are applied to your skin and reactions (wheals or hives on the skin) are evaluated, is not an intolerance test – that would be an allergy test.

I want to do an intolerance test – do I need to do anything beforehand?

It’s important to eat and drink as normal before doing your food intolerance test. If you currently avoid foods, this may affect the accuracy of the test results as it may reduce the level of antibodies in your blood. If you are currently avoiding some foods but still having symptoms, it is possible that you may still be consuming your trigger foods, and these may be identified with raised antibodies on your food intolerance test.

How can I do a food intolerance test?An Elimination Diet Typically Lasts 3-4 Weeks

You can order a food intolerance test from Healthy Stuff – the kit will be sent direct to you, and you can take the test from the comfort of your own home.

The full instructions on how to use the finger-prick blood test kit will be in the box, and your sample can be returned in the standard postal system – no phlebotomist or special couriers needed.

How are the results of a food intolerance test interpreted?

Your results will return showing negative, mild, moderate, or high levels of antibodies to specific foods. The higher the level of antibodies produced, the more likely you are to see symptoms of that food.

The initial recommendation would be to embark on a temporary elimination diet, removing any “high” antibody foods. This elimination period typically lasts 3-4 weeks. Following this period, you can begin reintroducing the eliminated foods one by one, carefully observing any symptoms that arise as you do so. This systematic approach will allow you to pinpoint potential triggers for your symptoms.


Testing for food intolerances with a finger-prick blood test can provide valuable insights into potential triggers for your symptoms and empower you with the knowledge to adjust your diet, which, based on testimonial evidence, could enhance your overall quality of life. You can purchase your test here.