Food allergy vs. food intolerance: How to tell the difference
- 3 Minutes Read
Food allergy vs. food intolerance–they may be used interchangeably — but they actually mean very different things.
How to sort out food allergy vs. intolerance
There are significant differences in the nature and treatment of a food allergy versus a food intolerance. Learning the distinguishing features of each can help you create a plan to manage symptoms, make informed food choices, and feel more in control of your health journey.
Food allergy: When your immune system goes on high alert
A food allergy is an immune reaction where the body mistakenly identifies certain foods as harmful invaders.
Food allergy symptoms
Food allergy symptoms can occur from almost immediately to up to two hours after eating an allergen, and can include:
- Hives or rash
- Swelling of the face, lips, or throat
- Trouble breathing
- Stomach pain or vomiting
- Anaphylaxis (a severe, life-threatening reaction)
Even a tiny amount of the allergen can cause a strong reaction. That's why people with food allergies typically need to avoid their allergens altogether.
Common food allergies
Although you can be allergic to any food, the most common food allergens are milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, and sesame seeds.
Diagnosing food allergies
If you suspect a food allergy, it is essential to consult with your healthcare provider. Food allergies are diagnosed with blood and skin tests, as well as a review of symptoms.
Note: Celiac disease is not a food allergy, but is an autoimmune response to gluten which causes damage to the small intestine.
Food intolerance
Unlike an allergy, food intolerance doesn't involve the immune system. Food intolerances often result from difficulty digesting or breaking down specific food components.
Food intolerance symptoms
- Bloating
- Gas
- Stomach cramps
- Diarrhea
- Headache
These symptoms are uncomfortable but not dangerous, and they typically occur a few hours or even days after eating a triggering food. People with food intolerance can often eat small amounts of the problematic food without a severe reaction.
Common food intolerances
The most common food intolerance is lactose, also known as “milk sugar.” People may also have intolerance to gluten (in non-celiac gluten intolerance), alcohol, caffeine, histamine, food additives, and more.
Diagnosing food intolerance
Food intolerance can be trickier to diagnose. Unfortunately, laboratory and at-home tests lack strong scientific validation. Research indicates that they don't consistently match symptoms and can produce false positives, leading to unnecessary food restrictions. Currently, the American Academy of Allergy and Immunology recommends against the use of such testing.
“Breath tests” may help detect malabsorption of certain carbohydrates such as lactose and fructose, but are not often covered by insurance. However, you may be able to determine sensitivity to such components by eliminating the food from your diet for a period of time and monitoring your symptoms.
Consider working with a registered dietitian to help you identify food intolerances and develop a balanced eating plan that helps you feel your best.
Tracking with MyNetDiary can help
If you suspect a food is causing issues, tracking your foods and symptoms is one of the best tools you have. Tracking and noticing patterns can help you distinguish between a possible food allergy vs. a food intolerance.
Tracking with MyNetDiary helps you:
- Spot patterns between what you eat and how you feel by adding notes or creating a custom tracker.
- Monitor portion sizes and timing of your food choices.
- Communicate with your healthcare provider by sharing relevant reports.
- Ensure you are getting the nutrients you need on a limited diet
- Find appropriate recipes. The app features over 600 Premium recipes, complete with filters to help you avoid common allergens.
Feel your best by finding what foods work for you
Understanding the difference between a food allergy vs. a food intolerance is key to managing your health and wellness. With the right tools and support, you can get to the root of what's bothering you and enjoy eating with confidence again.
Related content
Got trouble with milk? Try these proven tips for managing lactose intolerance
Gut troubles? Consider a low-FODMAP diet for IBS
How to lose weight on a gluten-free diet
Additional resources
American Academy of Allergy, Asthma, and Immunology
Food Allergy Research & Education
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Other Health Issues->Gastrointestinal (Gut)
Oct 27, 2025
