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Food Sensitivity Vs. Food Intolerance

by Donna Mastriani on Feb 14, 2025

If you're looking into food intolerance and sensitivity, you're likely experiencing symptoms after consuming a specific food, and you need to know what could be causing these symptoms. Food intolerances or sensitivities are quite common and affect more people worldwide. These conditions cause many digestive symptoms and discomfort, which can affect one’s quality of life by affecting work, school, and at-home chores. Getting a diagnosis is often the best course of action so you can be on top of your diet and avoid symptoms. The difference between food intolerance and food sensitivity is that a lack of sufficient enzymes causes food intolerance, while food sensitivity is caused by a reaction to food that isn’t IgE-mediated. Both conditions aren’t IgE-mediated; hence, they aren’t food allergies and are normally categorised as the same condition.

What is food intolerance?

Food intolerance is often a result of the small intestine's inability to digest a specific food. The inability to digest food often results from the small intestines producing insufficient enzymes to break down that food, causing indigestion. Common intolerances include lactose intolerance caused by inadequate lactase enzyme production in the small intestines. With age, the body stops producing sufficient enzymes to digest certain substances, especially lactose. So, when you have insufficient enzymes to break down a specific food, it leads to it being pushed into the colon, where it sits. The bacteria in the colon ferment the food, producing gas, which results in bloating. The food also takes in water from the body, which leads to constipation. It can take a while for the symptoms of food intolerance to go away because the body needs to get rid of the food for these symptoms to disappear. Once the food has left the body, intestinal symptoms like diarrhoea, stomach pain, constipation and others disappear. However, if you have other skin symptoms like rashes, those will take a few weeks to disappear.

What is food sensitivity?

Food sensitivity is a non-allergic reaction caused by a food you've consumed. Food sensitivity is often caused by your body being sensitive to your food. There is no real cause for most food sensitivities. It is common for specific food sensitivities to have a cause like caffeine sensitivity caused by an inherited gene. However, most of the time, you'll find that when you consume a food that you're sensitive to, you'll experience initial symptoms similar to those of food intolerance unless you eliminate that food from your diet.

Are intolerance and sensitivity the same thing?

Food sensitivity and food intolerance are terms often used interchangeably. That's because they tend to mean the same thing. Both food intolerance and food sensitivity don't involve the immune system, and they cause intestinal symptoms when those foods are consumed. They both mean that you're sensitive or can't tolerate the food you're consuming. While a food allergy can be described differently, food intolerance and sensitivity are described similarly. Both food sensitivity and intolerance can cause digestive symptoms and other mild symptoms like migraines and brain fog. However, they don't cause problematic symptoms like anaphylaxis, which can be life-threatening.

Symptoms of food sensitivity and food intolerance

Commonly, food intolerance and sensitivity symptoms can vary from one individual to the next. These symptoms can also vary in severity depending on how much of the trigger food you've consumed. The more you consume food you are sensitive to, the more severe the signs you'll experience. Common symptoms include:

Diarrhoea
Vomiting
Nausea
Stomach cramps
Headache
Brain fog
Joint pain
Constipation
Gas

Food sensitivity or intolerance symptoms can last for a few days until you've passed the food for the symptoms to disappear. Often, food sensitivity symptoms show a few hours after consuming the food to a few days. It can take up to to three days for the symptoms to manifest, which makes it hard to pinpoint the offending food. It is possible to have an intolerance or sensitivity to any food or ingredients in foods. These can range from gluten to food additives and dyes. It is also possible to have more than one food sensitivity. In such cases, it's essential to consult a doctor so that you can get nutritional advice in case you need to eliminate both foods from your diet.

Diagnosing food sensitivity and intolerance

Suppose you've been experiencing intense symptoms after eating a specific group of foods. In that case, getting a Sensitivity Test is essential, which will help identify which particular food or ingredient is causing your symptoms. That way, you can eliminate it from your diet or consume it in small amounts to prevent upsetting your digestive tract. Food sensitivities or intolerances can often be due to underlying illnesses affecting the gastrointestinal tract. For example, conditions like irritable bowel syndrome, ulcerative colitis, and damaged intestinal walls can result in food intolerance because the digestive tract cannot function at full capacity. In such cases, dealing with food intolerances and sensitivities and ignoring the underlying conditions is like putting a bandaid on a cut leg. You need to acknowledge the issue and the root problem, then deal with your food intolerances. Dealing with these underlying conditions can result in the damaged intestinal walls healing and the body being able to digest foods it was once sensitive to. So, you must also consult your doctor to look for intestinal conditions you could suffer from. These will help you better manage your symptoms and sometimes even relieve your sensitivities. There are two ways of determining your food sensitivities or intolerances. You can either do it through a blood test or a hair test. With a Hair Sensitivity Test, you purchase the kit online and get an email with a form you must fill out. You'll then send the hair sample to the lab for testing, ensuring you get a few strands of hair and get hair with the root or cut it very close to the root. However, when it comes to blood intolerance tests, you need to order the test kit online and wait for its arrival within three days. Afterward, you can collect your blood sample by pricking the tip of your fingertip as instructed in the instructions with the kit. Then, mail your blood sample to the lab for testing. You'll receive your results within a week of the sample arriving at the lab. Both methods test your sample against several common foods that cause intolerance and sensitivity symptoms. You have to see which ones are the problem. After you get your results, you can go on an elimination diet under the guidance of your doctor, and after the elimination period, add those foods back into your diet and see if you still experience the same symptoms. An elimination diet can also help you understand your intolerance to different foods to know whether you need to add them back. If you're highly sensitive to certain foods, cutting them off from your diet is probably best. However, when cutting foods from your diet, you must replace them with other equally nutritious foods. Ensuring you have a balanced diet even after eliminating certain foods from your diet will keep you from having deficiencies that can be detrimental to your health. A nutritionist can help you by checking whether you're meeting all your macro needs daily and help you meet them where you need to.

Final thoughts

Food sensitivity or intolerances cause digestive symptoms due to the inability to digest specific foods. These can arise due to underlying conditions, insufficient enzymes, or sensitivity to particular foods. Either way, suffering from digestive symptoms can mess up the quality of your life. A Sensitivity Test can help you determine what foods you're sensitive to. Learning about sensitivities or intolerances can help you manage your diet. There is currently no cure for food intolerances, and you must avoid problematic foods in your diet. In cases of lactose intolerance, you can take an enzyme to help you digest lactose. However, in other food sensitivities, you can only take over-the-counter medications like antidiarrhoeal or painkillers if the symptoms persist.

Author: Donna Mastriani, S.N.H.S. Dip., Nutritionist / Care Manager

Donna has a diploma in Advanced Holistic Nutrition and 10 years customer service experience so is perfect as the Customer Care Manager, who manages the 24/7 team for global support.