Food intolerances vs. food allergies: what’s the difference?

While it’s possible that your nutrition client may have some food allergies, they may have certain food intolerances instead. It can be easy to mistake these two, but how can you tell the difference? Here’s how you can nutritionally support your clients.

While food allergies and food intolerances may seem similar, they are actually quite different. As a nutrition professional, it’s important to know the difference between the two, as this can help guide you on the next steps to take with your client. Whether it’s ordering labs, changing their meal plan, identifying symptoms, or diving deeper into their medical history, knowing whether your client suffers from an allergy or intolerance will make all the difference when it comes to your nutritional care. 

But before diving into how you can work with your clients to identify these issues, let’s start by understanding the differences between food allergies and food intolerances.

Food allergies

Food allergies occur when the body’s immune system identifies a protein in food as an “invader” and creates antibodies (like IgEs) to fight against it [1]. These reactions can vary in severity, ranging from mild symptoms to severe, life-threatening ones. Interestingly, 90% of food allergies come from milk, peanuts, eggs, fish, wheat, soybeans, tree nuts, and shellfish  [1].

Some key symptoms of food allergies include:

• Anaphylaxis
• Severe gastrointestinal issues
• Hives
• Swelling
• Itchiness

Unfortunately, food allergies can’t be cured, but you can help your clients learn to recognize and manage food allergies by identifying which foods they should avoid to prevent serious health consequences. 

If your client is concerned that they may have a food allergy, instruct them to look out for these symptoms and have self-injectable epinephrine on hand, as well as being prepared to call 911 (or 112 in Europe) if they are unable to treat their allergy. 

Food intolerances

Unlike food allergies (where it affects your immune system), food intolerances are far less severe and not life threatening. This is defined as when your client has difficulty digesting certain foods and experiences an unpleasant physical reaction to them [2]. It also causes symptoms that happen a few hours after eating the food in question, and only if you eat a large amount of it (whereas with an allergy, even a small amount would have instant results). 

One example of a food intolerance would be dairy; if your client has digestive issues with dairy products, it could be that they are lactose intolerant (meaning that their body lacks the enzyme lactase needed to break down lactose). Other common culprits of food intolerances include wheat, gluten, caffeine, alcohol, artificial sweeteners, and MSG [2].

Some common symptoms seen in people with food intolerances include:

• Diarrhea
• Gas
• Nausea
• Cramping
• Constipation
• Bloating

Treating food allergies and food intolerances

As a nutrition professional, you can assist your client in avoiding any unpleasant (or life-threatening) effects from the foods they eat. Here’s how you can identify any food allergies or intolerances that your clients may have. 

• Undergo allergy tests. Whether or not your client’s symptoms are severe, it’s recommended to have them take an allergy test so you can better support them and get a deeper understanding of what’s going on. 
  
  
• Keep a food journal. You can have your clients keep a food journal and log everything they eat, as well as the symptoms they experience after each meal. This can help you determine which foods may be causing distress and if there are any patterns to be aware of.
  
  
• Elimination diet. An elimination diet can be incredibly helpful when trying to identify what foods are causing issues. This is when your client cuts out certain foods and then slowly reintroduces them one by one to see if there are any changes. However, if your client has a disordered relationship with food, this may not be the best option and should be handled with caution. 
  
  
• Identification. Once you have the allergy test results, and have gained useful information regarding symptoms and eating patterns, you should be able to determine if your client has a food allergy or food intolerance. Ultimately, if they have a food allergy, they must stop eating the food altogether due to the risk of anaphylaxis and harm to the body. However, if your client seems to have a food intolerance, you can work with them to cut back or avoid the food if possible, and find alternatives to try instead. Learn more about how you can create a meal plan that fits your client’s nutritional needs here.

Summary

Knowing the difference between a food allergy and food intolerance can further help you provide your clients with the best nutrition care possible. After assessing their symptoms and severity, you should be able to identify if they are intolerant or allergic to certain foods. As such, you can create a well-rounded nutrition plan to help your nutrition clients live a healthful and comfortable lifestyle without any negative (or life-threatening) side effects. 

We are always working toward bringing you the best nutrition content, so we welcome any suggestions or comments you might have! Feel free to write to us at info@nutrium.com.

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References:

1. Center for Food Safety and Applied Nutrition. (n.d.). Food allergies. U.S. Food and Drug Administration. Retrieved May 23, 2022, from https://www.fda.gov/food/food-labeling-nutrition/food-allergies 
   
   
2. NHS. (n.d.). Food intolerance. NHS choices. Retrieved May 23, 2022, from https://www.nhs.uk/conditions/food-intolerance/