Food Intolerance Symptoms Chart: What To Expect

Have you, like me, enjoyed the occasional donut all your life, but then one day suddenly realize that every time you indulge in them, you get a tummy ache? That typically points to a developed food sensitivity or  intolerance which presents during adult life. 

I absolutely love bread in any shape or form. However, I have recently discovered that, whether the gluten or straight up the wheat, are not my friends anymore. If I get to eat them I feel bloated afterwards and my digestion is a nightmare. Not to mention the ‘evacuation’ process. 

Food Intolerance Symptoms Chart

Same happens with dairy products and, in general grains. I haven’t been diagnosed with celiac disease at all but I consider myself sensitive to it. Therefore follow a gluten-free diet now.

Food allergies and intolerances are different because allergies are typically born with you, and intolerances appear over time – usually in adult life for various reasons.

Understanding the reasons for this and learning how to manage it is essential for your physical health and mental well-being. 

Can you develop Food Intolerances later in life?

Food intolerances can develop later in life due to different factors, like a weakening immune system. Other reasons include stress, pregnancy, illness, medication, diet, or lack of exposure to allergen foods as a child. Symptoms take time to appear due to the younger body’s threshold and it is more and more common nowadays.

Allergies are typically something most people are born with, affecting the immune system. They are discovered when children are young. Usually, once they start eating solids or are introduced to a specific allergen food for the first time. 

Food intolerance does not directly affect the immune system. We need to bear in mind though, that we are a system and everything is connected. So a week immune system will cause a weaker digestive system and vice versa.

While it can be discovered in childhood and adolescence, it is likely to only develop later. Sometimes people notice symptoms after age 18, while others get affected much later – between 30-50 years old. 


How do I know what food intolerance I have?

As I said, I have only knowm about my intolerances in my 40s and, although there are several ways to determine this, one way is to keep a food diary and record any symptoms you experience after eating certain foods. 

Another way is to try an elimination diet, where you remove certain foods from your diet for a period of time and then gradually reintroduce them to see if any symptoms occur.

Blood tests can also be done to detect specific food intolerances, such as IgG food sensitivity tests or lactose intolerance tests. I did all of those and didn’t get any results. It was all negative for allergies and/or intolerances.

It’s important to note that food intolerance symptoms may take days or even weeks to appear, so it can be difficult to identify the specific food or ingredient that is causing the problem. So it is not easy, trust me.

But don’t dispair, listen to your own body and observe what comes down well and what doesn’t, start there.

gut health

The Cause Of Developed Food Intolerance 

The cause of food intolerances occurring later in life is an ongoing question. Many people are curious how you can eat and enjoy particular food for 20-30 years, and then suddenly, those foods don’t agree with their system and start affecting them.

It is a fact and affects more of the world’s human population than most people realize. 

There are a few reasons for food intolerances developing only at a later stage in life, as listed and described below: 

Weakened Immune And Digestive Systems 

A weakened immune system causes issues with gut health, causing a weaker digestive system. When the digestive system weakens, it works harder to break down and digest certain foods.

The immune system is still developing as a child, but it has a stronger threshold, and the digestive system works faster and more efficiently. That changes as you get older. 

Causes of deterioration in the immune system as you get older: 

Age: The body’s natural aging process causes the immune system to slow down and respond to fighting illness slower. 

PregnancyPregnancy is challenging for the female body as the fetus and unborn baby use the mother’s resources to grow and survive. Pregnancy and childbirth affect the immune system and hormones, which rarely recover after birthing. 

Illness: While a weakened immune system can be the cause of picking up illnesses in itself. Some major illneses like cancer, autoimmune diseases, etc., along with their treatments and surgeries, take a major toll as well. 

StressStress and mental illness, such as anxiety, depression, PTSD, etc., affect how the brain functions and reacts to life’s stressors. In turn, it weakens the immune system and causes gut health issues. 

Diet: The type of food we eat and the chemicals contained in the ultra processed food, changing how you eat, like eliminating specific foods for extended periods, doing crash diets, or eating poor nutrition, can also weaken the immune system leading to gut health issues. 

MedicationsMedications, over-the-counter, chronic, short-term, and long-term, can be detrimental to the body. While medications are meant to fight off illness and pain, they can also be harmful.

Antibiotics, for example, when taken too often or for extended periods, can cause issues in the gut because it wipes out good bacteria essential for an effective digestive process. 


Lack Of Or No Exposure To Allergen Foods As A Child 

Another cause of food intolerances developed later in life is a lack of exposure to allergen foods as a young child. Health professionals recommend slowly introducing all types of food in small doses to babies once they start solids.

Sometimes that does not happen for various reasons, and the children don’t get the opportunity for their bodies to learn to fight those allergens. 

When these foods are only introduced later, when the children are bigger or teenagers, the body does not show intolerance symptoms because the young, strong digestive system can absorb and digest it quickly. 

As the body reaches adulthood and starts aging, the immune system weakens. It then picks up those allergen foods as something foreign trying to attack the body but cannot fight it through digestion fast enough, causing sensitivities resulting in intolerances. 

An Inability To Notice An Existing Tolerance Early On 

A common cause of food intolerances getting picked up later in life is the lack of noticing possible symptoms early on or during childhood. The symptoms often exist, but parents and the affected individual either do not notice it, ignore it, or assume it to be related to something else, such as eating too fast, not drinking sufficient water, or eating spicy food. 

The body may show symptoms irregularly, depending on how much or how often you eat the allergen food – another reason why it is not noticed earlier. The sensitivity may also exist but not show up in symptoms because of the younger, stronger immune systems’ threshold and fast digestive system metabolism. 

The body then only shows symptoms later as you age, and your metabolism slows down, resulting in apparent signs of intolerance each time you eat a specific food that causes that sensitivity. 

What is the Difference between Intolerance and allergy?

They are two different things, even though they both can cause symptoms after eating certain foods.

food intolerance is when your body has trouble digesting certain foods, such as lactose (milk sugar) or gluten (a protein found in wheat, barley, and rye). This can cause symptoms like gas, bloating, stomach cramps, and diarrhea. This is usually not life-threatening, and the symptoms can often be managed by avoiding the offending food or taking over-the-counter medication.

food allergy, on the other hand, is an immune system reaction to a food that is normally harmless. Common food allergens include peanuts, tree nuts, fish, shellfish, milk, eggs, and wheat. 

When someone with a food allergy eats the offending food, their immune system reacts and causes symptoms like hives, swelling, difficulty breathing, or in some cases, anaphylaxis (a severe, life-threatening allergic reaction). Food allergies can be very dangerous, and people with food allergies need to be very careful about what they eat.

So, in a nutshell, a food intolerance is a digestive problem, while a food allergy is an immune system problem. 

Food intolerance and allergy chart
Food intolerance and allergy chart

Food Intolerance Symptoms 

If you are curious to know if you are intolerant to specific foods, always look out for symptoms. You will often experience the same symptoms each time you eat something disturbing your gut health. 

These are the most common symptoms of food intolerance: 

  • Abdominal pain
  • Bloating and gas 
  • Headaches or migraines
  • Fatigue or difficulty concentrating
  • Skin rashes or eczema
  • Irritable bowel syndrome (IBS)
  • Nasal congestion or runny nose
  • Nausea or vomiting
  • Constipation/ diarrhea 
  • Reflux or heartburn
  • Joint pain

Food Allergy Symptoms 

As explained these are more serious and can lead to fatal consequences if not identified and treated.

As opposed to the most common allergy symptoms like:

  • Sneezing and runny nose
  • Itchy eyes, nose, and throat
  • Nasal congestion
  • Coughing
  • Watery eyes
  • Hives or rash
  • Swelling of the face, lips, tongue, or throat
  • Shortness of breath or difficulty breathing
  • Abdominal pain, diarrhea, or vomiting
  • Dizziness or fainting
  • Anaphylaxis

Most Common Food Intolerances 

When you notice symptoms of food intolerance, you must look out for the foods that are causing these symptoms. One or sometimes a couple of allergen foods trigger your sensitivity. 

These are the type of food intolerances that you can develop: 

Lactose Intolerance 

A sensitivity to lactose (a sugar) that come from dairy is one of the most common intolerances adults develop and experience later in life. Foods that include lactose are dairy milk, cheeses, chocolates, ice creams, butter, etc. 

Gluten Intolerance 

Another prevalent food intolerance developed and experienced by many later in life is gluten sensitivity. Gluten (a protein) is found in wheat, barley, and rye. These foods include bread, pasta, cereals, baked goods, beer, etc. 


FODMAP sensitivity occurs from a group of carbohydrates and often leads to gut health conditions like IBS (irritable bowel syndrome) or SIBO (Small Intestines Bacterial Overgrowth). High FODMAP foods include yogurt, barley, fruits like apples and pears, and certain veggies like cauliflower. 


Caffeine Intolerance 

Some people are more intolerant to caffeine than others. The body struggles to metabolize the caffeine. That causes symptoms like jitteriness, running stomach, headaches, hypertension, etc. Tea, coffee, chocolates, etc., contain caffeine.


A less widespread but existing food intolerance is sensitivity to amines. This organic compound contains nitrogen and is found in foods such as avocados, fruit juices, fermented foods, wine, fish, processed meats, etc. 

Food Additives 

Processed and packaged foods contain elements that enhance and preserve the color, smell, texture, and flavor, which can be high-allergen substances and cause intolerances.

Some foods containing additives and preservatives like the controversial monosodium glutamate, are artificial sweeteners, preserved meats, fish, wine, candy, chips, etc. 

How long after eating does food intolerance occur?

The symptoms of a food intolerance can occur anywhere from a few minutes to several hours after eating the offending food. For some people may be within a few hours of eating, while others may not have symptoms until the next day or even longer. 

The symptoms can also be delayed and may take days or even weeks to appear. This can make it difficult to identify the specific food or ingredient that is causing the problem.

It’s important to note that these symptoms are typically less severe than those of a food allergy and may include things like bloating, gas, abdominal pain, diarrhea, constipation, headache, fatigue, vomiting and skin rashes.

What Happens If You Ignore A Food Intolerance? 

It is not recommended to ignore food intolerance. To determine your food intolerance, reduce or eliminate the foods causing your sensitivities. Once you notice changes, entirely eliminate them or eat them in moderation. 

You should also visit your health professional for further advice, especially if your symptoms are bad or constant. Ignoring a food intolerance can continue to affect your physical health and mental well-being over time. Living with those symptoms can become more challenging and become allergies or result in major illness. You might need to take chronic medications or end up hospitalized. 

Does Food Intolerance Get Worse Over Time? 

If you are lucky or manage your diet well, your food intolerances may disappear. Your body has the ability to outgrow sensitivities. But as you age, your immune system gets weaker, and your digestive system gets slower and struggles to break down foods causing food intolerances to worsen as you age. 

Can You Manage Food Intolerance? 

Food intolerances can be managed. It might be challenging and a major lifestyle adjustment, but eventually, you will notice the benefits. By reducing the consumption of your trigger foods or eliminating them, you can experience fewer to no symptoms. 

Small amounts of your trigger foods are unlikely to majorly affect you, specifically if your intolerance is not too bad or you are younger. You can also take over-the-counter medications like antacids, antidiarrheals, pre and probiotics, and gut health supplements to help strengthen your immune system, regulate your digestive system, and reduce sensitivity symptoms.  

Are Food Intolerances Permanent? 

Food intolerances are not always permanent. Some people can outgrow their sensitivities. For others, it is lifelong and remains manageable with reduced consumption, elimination, medications, and lifestyle changes. 

Although they are not life-threatening like food allergies, they are really inconvenient, can worsen over time, and cause other illnesses if not managed correctly. 


Food intolerances can develop later in life due to several factors. In any case, it will be different for every person since we are all unique. This implies it takes patience and observation and, in general in my experience, a much more conscious living in order to identify what is causing you symptoms.

It is very important for me in this message to say that they can be managed, and symptoms can be reduced. Also, a healthcare provider who has an integral and holistic approach to this problems will be able to help further with your collaboration.

Watch out the foods you ingest, read all the food labels (I tell you now you’ll be left with just the fresh section to buy from).

In my humble opinion, this is the way to go as opposed to ingesting more chemicals that will only worsen the situation.

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