Food Sensitivity Symptoms & Testing Explained- 2023 Guide
Have you ever wondered why you have the strong urge to nap after a meal? Notice that you blow your nose constantly after certain foods or perhaps you have a breakout on your skin like acne, eczema, psoriasis etc. – at random points throughout the month? Well, the chances are that you may have a food sensitivity to thank for that!
With that understanding, you will probably be asking yourself, “how can I find food sensitivity testing near me?”
Alright, let’s go!
What is a Food Sensitivity?
A food sensitivity is a reaction in the body that involves the immune system and typically causes us to experience aggravating symptoms such as fatigue, headaches, joint pain, stomach discomfort, sinus drainage or congestion etc. after we have been exposed to an otherwise harmless food substance.
What causes this reaction? Well, after we eat that particular food, the circulating white blood cells in our body release chemicals into the bloodstream called mediators. Mediators promote inflammation. The end result of this cascade of inflammation? The annoying symptoms mentioned above.
Think of it as your body attacking food molecules, confusing them for evil foreign invaders.
And yes, for the record, it is 100% possible for your immune system to “dislike” a certain food today that you have previously consumed without a problem.
The craziest part about this whole concept of food sensitivities is that thousands upon thousands of individuals are walking the earth at this moment suffering from chronic pain, fatigue, poor recovery from illness or injury etc., assuming that this sub-par state of health is just “life” or “aging.”
Let’s be honest, the medical community is very quick to prescribe medication before suggesting that an individual begin an elimination diet first to rule out food-related symptoms. Yes, I know removing a laundry list of foods is not the “easy” way out but don’t you want to get to the root of your health issues vs. masking them with a
Some of the most common root issues that eventually lead to food sensitivities include but are not limited to mold, parasites, and tick-borne illness.
What is the Mechanism of Action?
When your body undergoes a food sensitivity reaction, it occurs through two main pathways: Type III and Type IV delayed hypersensitivity reactions:
Type III: IgG, IgA, IgM antibodies bind to food antigens. The binding to antigens causes white blood cells to release mediators. The release of mediators is what causes symptoms. 
Type IV: white blood cells are independently triggered (without roping in antibodies) to release mediators.
There are several other mechanisms of action such as cytotoxic reactions which deal primarily with food chemicals (i.e. solanine) vs. the actual food itself (i.e. potato).
In other words, it may not be the food itself that you are reacting negatively to, but instead a compound, often naturally occurring, within that food.
Regardless of the type of mechanism, there is one constant in the food sensitivity equation: white blood cells trigger mediator release and this is what directly causes those aggravating symptoms you are experiencing.
Now, have you already started to battle this puzzle to try and figure out what is the root cause of your issues by taking a food sensitivity test?
If so, you may be wondering, “Is the food sensitivity test I took accurate?”
Well, if it did not measure all forms of mediator release, the answer is probably no. If you are not sure, ask the health care provider who administered the test.
Want to learn more? Check out my article regarding the best food sensitivity test.
Could My Current Health Condition be Related to Food Sensitivities?
Yes, yes, yes! In fact, the research is mounting when it comes to food sensitivities and chronic health conditions, especially those that are autoimmune in nature.
Below is a current list of health conditions linked to food sensitivities:
- Acne 
- Eczema 
- Psoriasis 
- Irritable Bowel Syndrome 
InflamatoryBowel Diseases [10, 11]
- Reflux 
- ADHD [14, 15, 16]
- Autism [17,18]
- Chronic Fatigue Syndrome [19,20]
- Depression [21,22]
- Migraines [23, 24, 25]
- Fibromyalgia [26, 27, 28]
- Rheumatoid Arthritis [29,30]
- Eosinophilic Esophagitis (EOE) 
Am I saying that certain foods caused your–Hashimotos, IBS, Multiple Sclerosis, Eczema, you fill in the blank? No, I am not, but food sensitivities may be exacerbating your condition and possibly even intensifying your symptoms.
The removal of food sensitivities in an attempt to alleviate chronic symptoms is something I have successfully witnessed over and over again in my private practice.
Is This the Same as a Food Allergy?
As you may know by now, a food sensitivity is actually a completely different biological reaction than a food allergy or food intolerance. Although, I definitely understand why that might seem confusing as many healthcare providers use the terms interchangeably. (Check out my previous article that explains the difference between an allergy, sensitivity, and intolerance for a quick refresher).
A true food sensitivity involves the immune system (unlike a food intolerance) and is classified as a non-IgE reaction in the body (unlike a food allergy.)
There are two reasons why food sensitivities are sometimes hard to pinpoint without testing:
- Your reaction to a food sensitivity tends to be dose dependant. For example, you might have a few splashes of milk in your coffee in the morning without any noticeable symptoms. But then, by the time lunch rolls around and you’ve had a big glass of post-workout chocolate milk, you might find yourself hanging out by the toilet a little longer than expected.
- Your reaction to a food sensitivity is often delayed. For example, you might feel great after scarfing down a big bowl of pasta after a training session one night. However, you may not realize that extreme fatigue and difficulty getting out of bed the next morning or the stiffness in your joints the following afternoon is actually your body’s delayed reaction to the gluten-laden pasta consumed the night before.
Wait, But How Will I Know It’s Not a Food Allergy?
Very good question.
Food allergies are actually not nearly as common as food sensitivities.
In fact, food allergies in the United States are reportedly found in approximately 4-6% of the population vs. a whopping 30-40% of the population for food sensitivities! [4,6]
This is where food sensitivities become problematic, because you may go years without know how these foods are wreaking havoc on your immune system.
Keep in mind that if your symptoms are a result of a food allergy, they will occur very shortly if not immediately after consumption. You may also find that it is accompanied by vomiting, nausea and/or extreme gastrointestinal discomfort.
Interested in diving deeper into food allergies and learning about if they may be causing your stomach issues? Check out our post on how food allergies and intolerances cause stomach pain to learn how they may be affecting you and how to get back on the road to feeling great again.
In order to determine whether you truly have a food allergy, it is best to work with an allergist who can order an IgE blood test as this is the most accurate method to determine whether you are suffering from a food allergy. If you do not have access to this type of care, your best option is to begin a basic elimination diet. Here is a bit more info on how to get started.
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While a food allergy can extend well beyond the top 8 most common allergens, most individuals find that their main food culprit(s) tends to be on this list. Why? These are the foods most commonly consumed in our culture. These are also the foods most heavily treated and manipulated when it comes to farming and processing/manufacturing. Needless to say, the human immune system does not take well to this, especially if it is already inundated with environmental toxins.
Ok, back to food sensitivities.
What are the Most Common Food Sensitivity Symptoms?
Three of us might sit down to a nice big bowl of chocolate ice cream (FYI, I do not encourage anyone to eat massive helpings of dairy. This is just an example). You may experience gastrointestinal upset from it immediately, I may experience a headache two hours later, and our friend might wake up tomorrow with sinus congestion.
It is really unbelievable, but often it can take up to 3-4 days after consumption to experience symptoms.
Here are the most common food sensitivity symptoms:
- Joint Pain
- Brain Fog
- Bloating or gastrointestinal upset
- Sinus congestion or postnasal drip
- A sudden change in mood
- Rashes or a change in skin condition
- Inability to lose or gain weight
Also, for what it’s worth, food sensitivities can cause a sub-clinical reaction. In other words, they can cause “silent” inflammation. This means that you may still be suffering from a food sensitivity even if you are not experiencing outward symptoms.
How Do I Know if I Have a Sensitivity?
Before jumping into testing, it is always best to start tracking patterns.
Step 1: Do you wake up feeling well each day or do you have a nagging symptom or two that you just can’t shake?
If you feel great day in and day out- your energy is always high, sleep quality is great, your stomach never bothers you after meals, your joints or muscles never hinder you from workouts or daily activities etc. and you really do not have anything that is getting in the way of your daily life, then I would not spend your time worrying about whether you have a food sensitivity.
Step 2: Start to track those nagging symptoms. When do they occur? When do they feel the most intense? I would also strongly consider tracking your food a long with your symptoms as you may find a correlation.
Step 3: If your symptom(s) has persisted more than a few weeks and you just can’t quite figure it out by tracking, it’s time to see a professional who specializes in food sensitivity testing.
Side note: There are many food sensitivity tests on the market. If you are on the hunt for food sensitivity testing, the method of testing that you choose should encompass all possible pathways when it comes to mediator release. While there is not a single test that can claim 100% accuracy, there is one test that I would strongly recommend above others. . More to come on that in my next article….
(For those playing catch up, please check out my previous article, Elimination Diet Meal Plan Guide in order to better understand which foods to choose in order to alleviate chronic symptoms.)
Do You Recommend Food Sensitivity Testing at Home?
No, I do not and here is why:
First and foremost, you ABSOLUTELY want someone properly trained ordering and interpreting your results, otherwise, you may not get the most out of testing, even if you follow the testing company’s instructions to a tee.
Trust me on this one; you will want a highly skilled clinician interpreting your results in order to feel your best in the most time efficient manner.
At this point in time, the most respected and reputable companies do not offer food sensitivity testing at home.
And, if I did not already make this clear enough, I will say it again: a food allergy is different than a food sensitivity. Therefore, if you are truly struggling to pinpoint the issue, you may want to consider testing for both adverse reactions.
Do you suffer from food sensitivities? Have you attempted an elimination diet or food sensitivity testing? We’d love to hear from you!