According to Dr. O’Neil-Smith, more than 20% of the population suffers from food allergies and intolerances. Elimination diets and IgG food antibody testing can be successfully used in clinical practice to address symptoms like bloating, constipation and diarrhea, fatigue, anxiety, asthma, joint pain, sleep disturbance, and headaches. As practitioners, we must relate this information to clients and patients in an easy-to-understand manner. When I introduce an elimination diet to my clients, I explain that eliminations diets are a great tool to identify food allergies and sensitivities. I would like the client to keep a food/symptom log for five days to see if there are patterns that can point to specific foods causing symptoms. The only downside is that not all reactions are immediate. Some foods can cause delayed reactions, meaning that an offending food can cause a reaction from several hours to several days after it has been ingested. This can make keeping a food/symptom log frustrating and confusing.

What Is The Difference Between An Allergy and A Sensitivity

I think that when we discuss elimination diets, it is important to understand the difference between a true allergy and a sensitivity. Food allergies can be life-threatening due to anaphylaxis. Food sensitivities can be caused by physiological and psychological issues. For example, leaky gut causes maldigested food particles to diffuse in the bloodstream, which causesimmune cells to mount an attack. Overgrowth of bacteria in the small intestine (SIBO) can cause severe reactions to fermentable foods, and it needs to be addressed with a very specific elimination diet called low-FODMAP. Enzyme deficiency and irritable bowel can also cause food intolerances. Stress and psychological factors can also be responsible for food reactions. To this day, there are foods I was forced to eat as a child that will literally make me sick, even though I do not have a true immune reaction to them. We can also be sensitive to “added” substances like food coloring, preservatives, and sulphites (Li, J. 2019).

Elimination Diets Need To Be Tailored To Individual Needs

For these reasons, the elimination diet needs to be tailored to the individual and their specific symptom burden. We must understand that an elimination diet does not merely remove foods, but it also prescribes that the client eats specific foods. For example, if leaky gut is the cause of food intolerances, we need to make sure that their diet includes plenty of gut healing foods. The same applies when we are dealing with food intolerances caused by imbalanced gut flora or irritable bowel. We can’t just refrain from eating offending foods; we must ensure that our diet is nutrient dense and health-promoting (Rinninella et al., 2019).

The good news is that food intolerances usually resolve themselves in a matter of 3 to 6 months, when the client avoids offending foods completely, and we address the root causes of the intolerances. While implementing an elimination diet, we monitor progress closely. This allows us to fine-tune the diet, and it also helps us to decide when the client is ready to reintroduce and to test the foods that were triggering a reaction. The reintroduction phase of the diet is as important as the elimination phase. We must not rush through the process. When symptoms have resolved, we will decide together which foods to reintroduce in the diet and in 

which order. It is important that the client tests one food at a time every 4 to 5 days. This allows us to see if there are any delayed reactions to the food that we reintroduce. Keeping a detailed food/symptom log is going to be very useful during the reintroduction phase. 


Li, J. (2019). Food allergy vs. food intolerance: What’s the difference? Mayo Clinic;

O’Neil-Smith, K. (n.d.). Using the elimination diet in clinical practice: Explanations and case studies [Video]. Genova Diagnostics.

Rinninella, E., Cintoni, M., Raoul, P., Lopetuso, L. R., Scaldaferri, F., Pulcini, G., Miggiano, G., Gasbarrini, A., & Mele, M. C. (2019). Food Components and Dietary Habits: Keys for a Healthy Gut Microbiota Composition. Nutrients, 11(10), 2393.

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