Close this search box.
Food sensitivity testing and symptoms. Get tested, eat right, and eliminate symptoms. www.nourzibdeh.com

Food Sensitivity Testing and Symptoms: 8 Things You Need To Know

Do I have a food sensitivity? Which food sensitivity testing is best? What are the symptoms of a food sensitivity? “My doctor tested me and everything came back negative.” Or, I got tested for food sensitivity but it didn’t work or I react to everything and didn’t know what to eat.” I get these questions or comments often, so in this post, I talk about the 8 things you need to know about food sensitivity testing, symptoms, and more.

In my latest episode of Thank Gut It’s Fixed Show, I talk about the 8 things you need to know to understand food sensitivity and make sense of your symptoms or any previous tests that you have had.

Figuring out your food sensitivities and eliminating them (short term as you will see why) will result in MAJOR transformation in how you feel. My patients drop their scores from close to 100 to 20! The test and the plan allow you to reset your body and your health.

Click HERE to download a questionnaire and see how high you score. I’d love to help you understand your score, so click HERE and schedule a phone call.

But, here’s the caveat. The test alone is not a fix-all solution. Interpreting the results, putting the foods and meals together, and addressing how to cooking the food is important. Figuring out what caused the sensitivities is a step that can’t be ignored. Was is leaky gut? Lack of digestive capacity? Gut dysbiosis? Inflammatory foods? Thyroid or other hormone imbalances? SIBO? Parasite? Toxic load? And the list can go on.

The reason I mention this is sometimes people ask me if they can just get the test done and if I could give them a simple plan to get by with. Nope. To truly get the results you desire, we must look at EVERYTHING that can be contributing. You must look at health from a holistic approach.

One thing people are relieved to know is that food sensitivities are not your ever-after. Your body produces new cells to line your gut every 3 to 5 days. Your whole gut flora and reaction will change every 6 months. What that means is that you have the potential, if you do things correctly, to heal your gut and restore its function so you don’t have to eliminate foods you reacted to for the rest of your life. Almost all my patients can bring foods they had to take out back, and that’s what I want them to be able to do. Eating a restrictive diet is no fun. It’s doable short-term and if it’s purposeful, but the last thing I want to do is eliminate foods and nutrients from someone’s diet forever.

So now that we got these things clear, let’s talk about the 8 things you need to know about food sensitivity testing and symptoms.

Food Sensitivity Testing and Symptoms: 8 Things you Need to Know



One: You May Have a Food Sensitivity and Not Even Know It

The symptoms of food sensitivities can be subtle. They creep up on you over time. Then, at some point you wake up one day and you wonder why you’re tired and foggy all the time. Why do your joints hurt? Or you realize that you don’t remember life without headaches, or bloating, or stomach pain.

These are some of the complaints people who come to me experience.

Most people are familiar with symptoms of allergic reactions, but Food sensitivities are very different. Food will trigger your immune system. Your immune cells are going to release chemicals, or natural inflammatory compounds, to fight the food. Your immune cells stop identifying the food as safe. Instead, they see it as foreign and therefore must be attacked.

Your symptoms will depend on where these immune-inflammatory chemicals are released. You may get a migraine or hyperactivity, and I have seen this with children as well too. You may have skin issues like hives, eczema, or psoriasis. You may get a digestive problem like bloating, diarrhea or stomach pain. You may get muscle or joint pain. People who have fibromyalgia or an auto-immune condition are very likely to have food sensitivity.

There’s not a single symptom that will absolutely diagnose a food sensitivity. It’s a systematic inflammation all over the body. The new you become lethargic, foggy, in pain, and very irritable.

Two: Food Sensitivity is Different from a Food Allergy

A lot of people tell me that their doctor tested them for food allergies and they were negative. They were told that it’s not food. And they left their doctor’s office wishing they had one so they do something about it! As I just mentioned, food sensitivity is different from a food allergy.

True food allergies cause acute and immediate reactions, typically 15 to 20 minutes after eating the food. The symptoms are obvious—the airways get obstructed, quick and sudden hives or rash, swelling of the eyes or lips. And they can be so severe that they cause an anaphylactic reaction.

Food sensitivities, on the other hand, are chronic and subtle headache, stomach pain, diarrhea, muscle and joint pain, fatigue, or irritability. It starts slow, then it gets more severe and noticeable over time.

Food sensitivity is different from food intolerance. Sometimes people say that they are intolerant to certain foods. However, food intolerances typically describe a digestion issue, not an immune issue. An intolerance is typically when you can digest and absorb a food, such as lactose or fructose intolerance. A sensitivity is when the food gets absorbed, and then it activates our immune system.

Food allergies are one type, or one pathway, of immune reactions. Food sensitivity happens through completely two different pathways; hypersensitivity 3 and 4. They complement each other. When someone comes to me with a food allergy test, we consider it in our plan. But alone, it’s just one part of the picture.

Three: Not all Food Sensitivity Tests are the Same

If you have done a food sensitivity test before, take a look at the result. What test did your doctor order?
One common food sensitivity test that doctors order is IgG Testing. The rationale behind this type of test is that when you eat food, your body will then produce an antibody (IgG) to fight it. So, measuring the antibody release to certain foods and have a high IgG value tells us that you have a sensitivity to that food.

However, this test only detects one pathway involved in food sensitivity, hypersensitivity 3. The details of that aren’t as important as knowing that food sensitivity can happen due to pathway type 4. This is when the immune cells don’t produce an antibody at all. They just fight the food by releasing their chemicals. If you just measure type 3, or the antibody response, you’re missing half and potentially even the more important set of immune reactions.

The other concern with IgG testing is that a high value may not necessarily mean that the food causes the symptom. If you eat food often, exposure to the food will lead to a high IgG value. It’s very common for patients to tell me that they followed their IgG test results but didn’t feel any better.

The other challenge with tests is that not all of them give you a specific way of introducing foods. A test is just raw data. How you interpret it and use it is a completely different thing. If a test showed you that you react to 20 foods and you were told to remove them, you will not feel better because you’re still eating 100 different foods that did not get tested. Since ANY food can cause a symptom, you may be eating something that is triggered by an immune reaction without knowing it. There’s no way to test for EVERY SINGLE food component, so following a specific plan based on the test is more important than the test results themselves.

Four: Food Sensitivity Symptoms are Delayed and Dose-Dependent

Delayed reactions mean that food can show a symptom up to 72 hours after eating it. Something you ate in the last 72 hours could be causing the headache or stomach pain you’re feeling now. Let me ask you this, what did you have for breakfast 2 days ago? Can you account for every single food ingredient and food chemical you ate over 72 hours? I don’t think so.

Food sensitivities are dose-dependent. Sometimes a bite of something is okay but a whole bowl is not, making it difficult to determine specific problem foods. Allergies are easier to detect because anytime you eat an allergic food, whether it’s a small or a large amount, the reaction will happen. And symptoms start to show up within half-an-hour.

Some doctors or websites will tell you to keep a detailed diary to find out which foods you’re sensitive to. But I find that diaries are complicated and useless. It can be 1, 4, 10, or 70 hours before a reaction shows up, and it can happen sometimes but not all the time, depending on the dose. Considering these, without a test, you will not be able to determine anything.

Five: Even a Healthy Food Can Cause a Bad Reaction

You can’t follow someone else’s plan because we are all different. Many people are following this or that diet to eliminate their symptoms. And while some elimination diets are very useful, at the end of the day, they are still generic cookie-cutter diets, assuming one plan fits all.

If you have followed any of these diets and you’re still having your symptoms, it’s very likely you’re reacting to something that’s healthy and safe. Any food can trigger sensitivity. I’ve had patients react to salmon, garlic, almonds, blueberries, cumin, or parsley. You want to know what specific food is not being tolerated by your own immune system. From my experience using this test for more than six years and helping hundreds of patients, there is not a single food that is always safe.

The results aren’t based on genes and don’t even run in families. I’ve worked with families where we got siblings tested, or mom and child, or dad and child, and they were never the same. It is impossible to have one plan that fits all and that’s the beauty of functional nutrition and functional medicine. It’s very individualized.

Six: A Food Sensitivity is a Source of Chronic Inflammation

If you leave food sensitivities untreated, it will have a trickle effect on other parts of your body. It will affect your thyroid and your adrenal health making you feel tired and fatigued.

Adrenal activation is going to cause a stress response, which will affect your insulin level, blood sugar management, and make you gain weight around the belly. Food sensitivities will affect your male and female hormones. You will retain more water. And your immune system will be occupied fighting foods instead of doing its job of fighting pathogens, and bacteria, the real microbes out there.

Inflammation is the number one cause of many chronic conditions like heart disease, diabetes, arthritis, cancers, and more. You must uncover, eliminate, and heal food sensitivities so that you can reduce overall inflammation and risk of more serious health conditions.

Seven: Causes of Food Sensitivities are a Improper Digestion and Leaky Gut

In episodes 2 and 3, we talked about leaky gut, what it means, side effects, and more.

Think of your food as a raspberry. Your digestive enzymes must break the raspberry into its little teeny tiny circular components so they can to pass through the layer of cells that line the intestine to be absorbed.

If your enzymes and digestion are not working properly because of long-term use of acid-blocking meds or eating quickly, or just due to age, food will not be broken down to its most basic single unit form. That raspberry is still lumpy. And when you have a leaky gut that allows large and foreign substances to pass through, immune cells view these lumpy particles are unknown and start to fight them, releasing chemicals and triggering your symptoms.

Eliminating foods from your diet without fixing the whole gut is only a short-term solution. That’s why I never offer the test alone and insist on following the plan at 100%. If you’re not going to do that, it’s a waste of time and money. Without restoring digestion with the right nutrients, healing the gut, balancing gut flora, and eradicating potential infections, food sensitivities will come back.

Eight: You Can react to Foods or Food Chemicals, both Natural or Man-Made

You can react to a strawberry or to the natural compounds in a strawberry. You can react to potatoes or the natural compound in potatoes and other nightshades. You may not react to any of those! Many patients with arthritis have eliminated nightshades foods to no avail only to get rid of the pain with the food sensitivity plan. Some people react to chemicals that develop naturally in leftover foods. I get people tested for foods and chemicals, and people are shocked how natural things can cause a problem.

When you’re ready to find the right foods for YOU so you have energy and no digestive, muscle, joint, or head pain, and no more brain fog, I’d love to talk. Download this questionnaire. Put a number (From 1-4 based on the instructions in the document) next to any symptom you have. Then click HERE to BOOK a phone consultation to review your answers.


Nour’s guidance and expertise was the key to dramatically halting our son’s [Crohn’s] disease progression! His pediatric gastroenterologist is now in agreement of our choice to treat solely with diet and supplements. All his labs have improved and his inflammatory markers are so low they are practically nonexistent.

Before working with Nour, I experienced intestinal pain off and on for for 54 years with minimal success on medications. I have benefited 100% from Nour’s program as I am now pain free!

A lot of time and money was wasted on foods that I thought would help my digestive struggles [diarrhea, bloating, hunger], but in fact I was making it worse. The main benefit is getting a handle on what negatively affects my digestive symptom. Doing a total 180 to my eating habits has been pretty amazing.