Food Sensitivity Explained

What is food sensitivity?

We typically think of big dramatic reactions when our bodies don’t agree with the food we have consumed—like an angry bout of hives, EpiPens and anaphylactic shock. Food sensitivities are different. Unlike common food allergies, these adverse reactions can be delayed and are rarely life-threatening.

Luckily, with growing awareness and food sensitivity testing capabilities, it’s easier than ever to get to the bottom of what is ailing you and do something about it.

But what many people don’t know is that food sensitivities are growing in prevalence and can affect our health and our moods. What’s more, food sensitivities are largely undiagnosed and seem to be on the rise. While they are clearly less scary than a full-blown food allergy, these mysterious and highly individualistic conditions can still make us sick. 

Allergy vs. Sensitivity vs. Intolerance: Understanding the science behind the symptoms

A true food allergy is an immune response to a specific food, triggering a histamine reaction with potentially severe symptoms like anaphylaxis or hives, with a near immediate reaction time. An example of an allergic reaction is someone with a peanut allergy, who requires an EpiPen simply by inhaling a tiny amount of peanut dust from a candy wrapper nearby. People who suffer from common food allergies typically know about their allergens based on the extreme reactions and immediate response times.

Food allergy

A food sensitivity is a diffuse, and as yet poorly understood reaction to food that may be associated with increased levels of certain IgG class antibodies that are reactive to that food. Unlike a true food allergy, the symptoms can be delayed for a few days after ingesting the trigger food. An example of this is when you start experiencing signs of a gluten sensitivity or peanut sensitivity. People who have food sensitivities can go a lifetime without ever knowing they have one due to delayed reaction times and vague symptoms that mirror common ailments. Some signs that may point to a food sensitivity include bloating, migraines, and diarrhea.

Food sensitivity

A food intolerance happens when you lack an enzyme needed to break down a certain food, triggering a digestive response. An example of this would be those with lactose intolerance, meaning they lack sufficient quantities of the enzyme lactase to break down the sugars in the milk, resulting in gastrointestinal trouble. Lactose intolerance symptoms can be similar to dairy sensitivity symptoms, but a lactose intolerance isn't the same as a dairy sensitivity (which is a form of food sensitivity and not a food intolerance). Intolerances commonly run in families.

Food intolerance

There are a lot of terms thrown around and it’s easy to get confused, especially since food allergies, food sensitivities and food intolerances often present similar symptoms and there’s a general lack of accurate information on the internet.

The key difference is how your body reacts once a trigger food is encountered. For both allergies and sensitivities, your body may produce certain classes of antibodies to triggering substances. Common food allergens prompt the production of IgE, while a food sensitivity may result from IgG reactions. Testing for these two antibodies is the most definitive way to distinguish between an allergy and a sensitivity, and an IgG test offers more insights on what foods are making you sick. Here are a few tell-tale signs to look for if you suspect your body is reacting poorly to a specific food:

  • Immediate response
  • Possibly life-threatening
  • IgE-mediated immune response

Key differences between food allergies and food sensitivities

Food Allergy

  • Response ranges from one hour to up to 48 hours
  • Not life-threatening
  • Possibly IgG-mediated immune response

Food Sensitivity

  • Acne 
  • Brain fog
  • Eczema
  • Dry and itchy skin
  • Bloated stomach after eating
  • Fatigue
  • Joint pain
  • Reflux
  • Migraines
  • Diarrhea
  • Depression and mood swings 
  • Runny nose 
  • Headache 
  • Trouble sleeping 
  • Dark circles under eyes

Food Sensitivity Symptoms

Do you suffer from any of the following symptoms? A food sensitivity may be to blame for your adverse reactions.

Common Culprits

While food sensitivities vary from person to person, there are some common culprits often associated with food intolerance. These include:

Cow's milk and other

dairy products

Gluten-containing foods 

(wheat, rye, barley)





Beef, pork and lamb (a lot of livestock is raised on corn and soy)

Food additives and processed foods like sulfites or artificial color

High FODMAPs foods, or fermentable oligosaccharides, disaccharides, monosaccharide and polyols, are certain carbohydrates found in common, often healthy foods and drinks that are fermentable, osmotic, and poorly absorbed, resulting in digestive distress and intestinal gas buildup.

Here are a few examples: dried fruit, stone fruit, cherries, apples, mango, papaya, sour cream, cottage cheese, yogurt, milk from cows, sheep or goats, beans, lentils, squash, garlic, mushrooms, cabbage, broccoli, onions, coffee, high-fructose corn syrup, agave and artificial sweeteners. Sorry, chocoholics, chocolate unfortunately falls into this category as well.

How do you know if you have a food sensitivity?

If you notice certain ailments or aches on a regular basis like the ones listed above, you might have a food sensitivity. The tricky part is figuring out which food is to blame. Since symptoms can wait to show up until a few days after consumption, it makes diagnosis especially challenging and time-consuming. That’s why for many, food sensitivities last for decades and are largely undiagnosed.

Traditionally, you would keep a food journal and embark on an elimination diet, removing possible culprits one at a time for periods of two to eight weeks (the longer the better). Instead of that tedious process, we offer simple at-home health testing for 96 different possible triggers, with results in five days. The home health test, which detects an IgG immune response, will zero in on possible triggers and expedite your diagnosis. Our at-home health tests are designed to keep you empowered and informed without the hassle and cost of lab work. Everlywell provides advice specific to your sensitivity so you can be on your way to a healthier self.

Living (and eating) with a food sensitivity

The bad news is that there isn’t a cure. The good news is that by simply eliminating the trigger food, you can be symptom-free. After you receive the results from our at-home food sensitivity test, Everlywell will provide tailored advice on how to move forward with your diet needs. While you might decide not to completely eliminate certain foods, scaling back on triggers will lead to a healthier relationship between your body and your food. It’s all about finding the right balance of minimizing symptoms and maintaining your desired lifestyle.

Here are a few tips to help you steer clear of those trigger foods and feel your best:

Educate yourself. Learn about ingredients in the foods you eat. It’s not uncommon for eggs, wheat, cow's milk and other reactionary foods to be called by other names. If you have a wheat sensitivity, peanut sensitivity, or sensitivity to tree nuts, keep in mind that these ingredients are often found in many processed foods.

Educate others. Depending on the severity of your symptoms, it may be a good idea to tell anyone preparing your meals about your food sensitivities. That includes family, friends and waiters. At restaurants, it’s always smart to speak up about your sensitivities since many times, these everyday ingredients can pop up on your plate without your knowledge and navigating the menu can be confusing.

Stock the pantry. For those who suffer from sensitivities to common foods (like gluten), it’s important to stock your pantry with safe foods and appropriate substitutes to keep you on track and to reduce cravings.

Pay attention to labels. Manufacturers can change ingredients of their products without notice, so double-check ingredient labels every time you buy a food, even if it is something you buy over and over.

Our customer service team is on hand to answer questions and help you better understand your results. As always, we encourage you to share your results with your healthcare provider.

Join the conversation. Once you take an Everlywell Food Sensitivity test, you are welcomed and encouraged to join our closed Facebook page to share stories and helpful tips with others who also live with sensitivities.

After you receive the results from our at-home food sensitivity test, Everlywell will provide tailored advice on how to move forward with your diet needs.