Food Sensitivity 101: A Guide to Optimizing Your Performance and Health

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Discover how food sensitivity testing can help you optimize energy, focus, and resilience, starting from your plate.

Written by: Dr. Madison Sangster-Newbery, ND, Naturopathic Doctor, Adelaide Health Clinic & Sport Medicine Clinic 

Let’s be honest, if you’re navigating long hours, endless emails, tight deadlines, and maybe a workout before breakfast - you can’t afford to feel anything less than your best. So, when you are eating healthy and still experiencing brain fog, bloating, fatigue, or stubborn weight gain, it’s frustrating. That’s where food sensitivity testing comes in. 

Food Sensitivity vs. Food Allergy: What’s the Difference? 

When we consume food, our immune system may respond by producing antibodies, which are proteins our body makes to protect us. Two common types are: 

• IgE antibodies: These trigger immediate food allergies, typically occurring within 5 to 30 minutes. Think hives, anaphylaxis, or swelling right after eating peanuts.  
• IgG antibodies: These are responsible for delayed food sensitivities which can take hours to days to cause symptoms, making them far less obvious and harder to track without testing.

What Causes Food Sensitivities in the First Place? 

One theory involves intestinal permeability, or what’s often referred to as leaky gut. Your gut lining is supposed to act like a filter, letting nutrients in while keeping larger, undigested food particles out. But when it becomes inflamed (due to things like chronic stress, alcohol, or certain medications), that barrier weakens. Food particles can then sneak into your bloodstream in the wrong form and at the wrong time. Your immune system flags these as intruders and produces IgG antibodies to attack them, setting off an inflammatory response that can affect your energy, digestion, mood, and more. 

How Food Sensitivities Can Disrupt Your Day 

IgG-mediated food sensitivities create complexes in your bloodstream leading to systemic inflammation. Over time, this can contribute to: 

• Digestive Issues: Like bloating, gas, constipation, diarrhea, and IBS symptoms. 
• Migraines & Headaches: Food sensitivities can increase migraine frequency.
• Mood & Cognitive Performance: Brain fog, anxiety, poor concentration, and low resilience to stress may be rooted in inflammation triggered by foods.
• Weight Gain: Inflammation leads to water retention and elevated ghrelin (a hormone that increases hunger), two factors that make it harder to manage weight despite your best efforts. 

For those in demanding, high-pressure roles, these symptoms can be more than just inconvenient, they interfere with your performance. 

Why Test? Why Now? 

Food sensitivity testing allows you to pinpoint which foods are contributing to inflammation and interfering with your performance. Common culprits include foods you may eat daily, such as dairy, wheat, eggs, soy, or yeast. 

Elimination diets can take months of being on a restricted diet, and you can still miss the mark. Since IgG reactions are delayed, you may feel symptoms hours to days after eating a reactive food. Making the connection can be nearly impossible. 

Testing can help you: 

• Remove the guesswork and save time 
• Understand your own unique immune responses 
• Get targeted, personalized nutrition advice  

So How Does Food Sensitivity Testing Work? 

We use a simple blood test to measure your immune system’s IgG response to a range of commonly eaten foods. You’ll receive a personalized report that shows: 

• Which foods are triggering inflammation for you 
• How reactive you are to each food 
• How your results compare to the general population 

This information helps us create a realistic and strategic plan to remove highly reactive foods for a short period of time to reduce inflammation, and support healing your gut. Testing is done through LifeLabs, and results typically arrive within two weeks.  

Once you receive your results, I will guide you through a strategic elimination plan. Within a few weeks, many individuals report improved energy, focus, digestion, sleep, and mood. While some experience temporary withdrawal-like symptoms (like headaches or fatigue), these are typically short lived.  

But Here’s the Thing… 

Food sensitivity testing isn’t for everyone.  That’s why I always recommend we have a preliminary discussion to assess whether this type of testing fits your symptoms, goals, and lifestyle. Sometimes we need to address overall health first. Other times, the test can provide the clarity we need to move forward faster. 

Food is Fuel - Let’s Make Sure It’s Working for You 

If your performance matters (and let’s face it, it does), the foods you’re eating should support your energy, mood, and digestion.  Food sensitivity testing can be a proactive step toward understanding what your body needs (and doesn’t need) to perform at its best.  

If you're feeling off and want answers, Food Sensitivity Testing might be exactly what you need.  

Interested in Learning More?  

Wondering if Food Sensitivity Testing is right for you? Book a free discovery call. I’d be delighted to discuss your options with you!  

About the Author

Dr. Madison Sangster-Newbery, ND is driven to help you achieve optimal health. Having personally navigated digestive struggles, Dr. Madison, ND understands the profound impact it can have on daily life. This experience ignited a deep commitment to finding natural and sustainable approaches to support digestion. She integrates a variety of naturopathic modalities, including herbal medicine, nutrition, lifestyle counseling, and mind-body techniques, into personalized treatment plans with the aim to empower individuals to regain control of their health by addressing the root causes and offering support that goes beyond symptom management.   

Dr. Madison Sangster-Newbery ND is currently licensed and registered to practice in Ontario under the College of Naturopaths of Ontario. She is a member of both the Ontario Association of Naturopathic Doctors and the Canadian Association of Naturopathic Doctors.  

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Please consult a licensed naturopathic doctor or other healthcare provider before making any changes to your health regimen or treatment plan.