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Food Sensitivity vs Allergy: Important Information To Know

Food sensitivity vs allergy is often a misunderstood and overlooked topic. If you have painful digestive issues, headaches, migraines, pain, fatigue, brain fog, or other nagging symptoms, you may have wondered if you’re reacting to certain foods. In this episode of Thank Gut It’s Fixed Show, I compare food sensitivities and allergies so you’re more informed when you discuss your options with your healthcare providers.

And if you’re not satisfied with the plan or options they’re offering you, read more about what I do to see if my program is what you’ve been looking for.

It’s possible that you went to your doctor and asked for a food sensitivity test. She may have reviewed your symptoms and concluded that they are not allergic reactions. She may have explained that you don’t have rashes, hives, swelling, or sinus issues. Despite your digestive discomfort, fatigue, or brain fog, she declined the testing or discouraged it. She may have said that food has nothing to do with it. You went home without a clear answer or plan.

Maybe your doctor did an allergy test. But few days later, the office called and said that your labs are fine. Maybe, it was completely the opposite. Your doctor hands you the result and says that you’re allergic to 10 different foods (your favorite ones!) and that you should NEVER eat them again. Maybe you got frustrated, or maybe you got excited because you finally found the answer. You eliminated the foods that were positive on the test, but the symptoms didn’t go away.

All these scenarios are possible. These are stories my patients tell me when we discuss their medical history. In order to get back your health, energy, and vitality, you need to understand the difference between a food sensitivity vs allergy.


Food Sensitivity vs Allergy

What are the Symptoms?

Food allergies tend to be acute and may be fatal if severe and not treated immediately. They can show up in the mouth such as swelling and tingling of the tongue or lips. They can be swelling in the airways, wheezing, or difficulty breathing. In the digestive tract, you may experience vomiting, nausea, or diarrhea. On the skin, you may develop a rash, hives, or eczema.

Food sensitivity symptoms are a lot more subtle and will be as severe or acute. They can show up in your head and cause brain fog, headaches, or migraines. They can show up in the digestive tract and cause stomach pain, bloating, diarrhea, or constipation. A food sensitivity can show up in your joints and muscles and cause pain and stiffness. It can be in your skin, causing rashes or eczema. While some of the symptoms overlap, a sensitivity is typically not an acute reaction.

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The picture below shows the wide range of symptoms and medical conditions that can be related to food sensitivities. Do food sensitivities cause all these issues? Sometimes, the answer is a yes. A food sensitivity can trigger the symptom. Other times, they worsen the situation or keep inflammation high. For example, if you have fibromyalgia and you’re reacting to a food, the inflammatory response of your immune system to the food will keep overall inflammation and pain level elevated. When you find out which foods are problematic and eliminate them, the immune system will calm down and your body will have the opportunity to start to heal.

Do you suspect that you have a food sensitivity? If you want to understand more about the mechanism of immune reactions, I talk extensively about food sensitivities HERE. You can also download a questionnaire to rank your own symptoms.

food sensitivity vs allergy

How Soon Do Symptoms Show Up?

Food allergies are immediate. Typically, the reaction will happen in the first hour after eating the food. Food sensitivity symptoms can show up after you eat the food too, but it may take up to 72 hours. That is usually referred to as being “delayed reactions to foods.”  This makes it very difficult to pinpoint problem foods. If I asked you what you had for dinner 3 days ago, you probably can’t remember! That’s why keeping a food diary is overwhelming and useless when it comes to discovering the foods you’re sensitive to. You would need to track all the meals and snacks you ate over a period of 72 hours. Considering the number of foods each person eats in 3 days, and the number of ingredients each food may contain, and the fact that the symptom can show up anytime between 30 minutes to 72 hours, trying to find a pattern needs a data analysis team!

Learn how to identify the REAL causes of your gut problems.

Download My Free Guide.

Does the Body React Differently in a Food Sensitivity vs Allergy?

Yes. Food sensitivities and allergies different immune system pathways. Food allergies are IgE-immune reactions. Your immune system will produce antibodies type E to attack the food. It uses the same mechanism to attack environmental substances like pollen, grass, mold, cats, dogs, etc.

Food sensitivities are also immune-reactions, but they are NOT IgE reactions. They happen through two immune pathways. First, your immune cells may produce a different type of antibodies, typically IgG, to attack foreign foods. This is often referred to as hypersensitivity 3. The second pathway is known as cell-mediated. That means the cells of the immune system bypass making antibodies and start attacking the food on their own. They’ll produce chemicals, known as mediators, to fight the food. This pathways is often referred to as hypersensitivity 4, and these tend to be more involved in food sensitivity reactions than IgG related pathways.

Food sensitivities tend to result from gut issues such as leaky gut syndrome, problems in digestion, and gut dysbiosis. Undigested food particles pass through the gut lining where the immune system cells await. They don’t recognize the food and release chemicals to attack it. The symptoms tend to be subtle and may take a long time to show up. You may be living with your symptoms not realizing that they’re an issue! You may think that it’s just a normal sign of aging, or having young kids, or being post-partum! Many times people rationalize these symptoms and compromise on their health.  Watch the video at the 12:50 minute mark when I walk you through immune reactions during food sensitivities.

How Common are They?

Food allergies are rare. They affect 4-8% of the population. On the other hand, food sensitivities are common and affect 30-40 % of the population.

What’s Amount of Food that Can Trigger a Food Sensitivity vs Allergy?

Food allergies are often NOT dose dependent. For example, if you’re allergic to peanuts, you can’t eat a single nut. A spec of the food can be a problem! Food sensitivities are dose-dependent. That means that you may eat a small amount and not experience a symptom, but the next time you eat a large portion of the same food, it will trigger a digestive discomfort, pain, headache, or something else. That’s why food sensitivities can be confusing to figure out! One day you eat it and you’re fine, and the next time you’re not.

Are there Typical Problem Foods?

For food allergies, 8 foods are typically responsible for 95% of the symptoms cases. These foods are dairy, wheat, peanuts, tree nut, fish, shellfish, soy, eggs, and corn. With food sensitivities, ANY food can trigger a reaction, even healthy ones! Things like salmon, blueberries, even spices like cumin and cilantro, turmeric can be problem foods. Many of the foods that my patients are sensitive to are super healthy or antioxidant-rich foods. The immune cells stops recognizing them as safe foods and starts to see them as foreign substances.

For How Long Do I Need to Eliminate Food Sensitivity vs Allergy Triggers?

If you have a food allergy, you’re stuck with it for the rest of your life. You can try to work with an allergist who has a special protocol for introducing the food VERY slowly in a controlled way in their office. They monitor your symptoms and are able to react if you start to wheeze or your airways to tighten. You should never try to experiment with food allergies on your own.

Food sensitivities are not your destiny. Once you address the root cause of the problem, improve digestion, balance gut dysbiosis, heal leaky gut, and address other gut inflammation issues, you will very likely be able to enjoy the food again without side effects or problems. I see this with my clients all the time. My program is 4 months long. At 3-month mark, we start to introduce foods that were positive for food sensitivity. Most of my patients can tolerate these foods again without problems.

IgG Food Sensitivity Testing – Side Note

While this post mainly focuses on food sensitivity vs allergy, I wanted to share that there are differences in testing even within the category of food sensitivities. Not all food sensitivity tests are the same. You may have done an IgG food sensitivity testing, but these are not as valid or useful. IgG stands for antibody type G. Remember that antibody-mediated reactions are only ONE type of food sensitivity reactions. Think of the antibodies as the trash pick-up truck, and they’re coming to pick up problem foods. The other way the immune system reacts is without antibodies. If you just have an IgG test, then you’re missing a big part of the picture.

IgG levels may be elevated not because the food is causing the symptom, but because you’re eating the food often. There isn’t a correlation between IgG values and triggering your symptoms. High IgG levels mean that your immune cells are recognizing its presence. If you just count on IgG levels to guide a meal plan, you won’t be able to pinpoint the foods that cause your digestive pain, muscle pain, brain fog, headaches, and others.

Food Sensitivity vs Allergy Take Home Message

Food sensitivities are different from food allergies. You may have one or the other, or both. A food sensitivity test will complement a food allergy test, especially if your symptoms don’t disappear despite removing the foods you’re allergic to. They are 2 different immune pathways. If you have a true food allergy, it’s possible that you ALSO have food sensitivity at the same time to the same food or others.

If you suspect that you have food sensitivities and need help with a customized meal plan, book a complimentary call with me to discuss your options.



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.