Food Allergy vs. Food Intolerance

If you’re out at a restaurant and ask for any modification to your food, you may notice servers are increasingly asking if it is because of an allergy or “preference.”  It is my belief that they use ‘preference’ synonymously with ‘intolerance’, when in reality the two are very different.

Food Allergy

A food allergy is an immune response by the body to some food particle, usually the protein in foods. For some reason, the body interprets the food as a foreign invader – a “bad guy” so to speak – and thus fires up the immune system to protect the body. Symptoms of an allergic reaction can include:

  • Hives or other rash
  • Swelling
  • Itching
  • Coughing
  • Shortness of breath
  • Throat tightness
  • Nasal congestion
  • Nausea
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Dizzy or lightheaded
  • Headache

The most common and also most dangerous symptoms of allergic reactions are swelling of the airway resulting in lack of oxygen, or drop in blood pressure, which leads to weakness and potential black outs. Allergic reactions can be deadly if not treated right away, which makes it super important that restaurants clarify whether a meal modification is for allergy reasons or not.

The most common food allergens are:allergens

Interestingly, mustard and sesame allergies are also becoming more prevalent.

Food Intolerance

A food intolerance occurs when the body is unable to properly breakdown a food. This may result in symptoms such as bloating, abdominal pain, gas, nausea, or diarrhea.

The most common food intolerance is lactose intolerance, where some people lack a specific digestive enzyme that helps to breakdown the sugar in milk (lactose). Food additives like MSG are also common intolerances.

Food Preferences

A preference is a choice, such as choosing what clothes to wear or how to wear your hair. People choose to eat various foods for various reasons. Someone may choose not to have chicken on their salad because they’re a vegetarian, decline beets at a buffet because they don’t like them, or decide to have just water instead of ordering a beverage to save money.


The main difference between a food intolerance and a food allergy comes down to the bodily system it affects. An allergy affects the immune system, while an intolerance affects the digestive system. Food allergies are also life threatening, while intolerances and preferences are not.

*If you happen to be in the presence of someone having an allergic reaction, administer their Epi-Pen (“blue to the sky, orange to the thigh”) and then call 911 immediately!

If I’m out at a restaurant and get asked why I’m modifying my food, I always say for allergy reasons, even if it’s not. I do this for two reasons:

(1) I believe that some think intolerances aren’t a real thing and

(2) Alternative products such as gluten-free products are more costly, so if it isn’t an allergy, the restaurant may feel it’s okay to give you the regular version, thus saving their more expensive products. I don’t know if this is actually true, this is just my belief. (*Side note: I’m super wary of gluten-free alternatives anyways, as most restaurants use corn as a base for their gluten-free versions. I am also intolerant to corn, so that doesn’t help me out at all. I usually just stick with naturally gluten-free things to be safe!)

Do you have any experiences with food allergies or intolerances? Let me know below!

I'd love to hear your feedback on this "food for thought!"