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Food Allergies and Intolerances

Contributors: Esther Ellis, MS, RDN, LDN

Reviewers: Academy Nutrition Information Services Team

Published: May 07, 2020

Reviewed: February 21, 2024

Food Allergies and Intolerances
Wojciech Kozielczyk/iStock/Getty Images Plus/Getty Images

Millions of Americans have allergic reactions to food every year. Food allergies tend to first appear in young children and are common in people who have a family history, but food allergies may be diagnosed in adulthood as well. Some children may outgrow certain food allergies as they get older but many food allergies are lifelong.

Food allergies occur when your body's immune system reacts to a substance in a food, usually a protein, that your body sees as harmful. This sets off a chain reaction within your body. Symptoms can occur within minutes and can range from mild (such as a runny nose or itchy eyes) to severe, and can even be life-threatening.

A food intolerance is not the same as a food allergy. Food intolerances have different causes. An intolerance occurs when your body is unable to digest a certain component of a food, such as lactose, a sugar found in milk. Symptoms of intolerance may be unpleasant, including abdominal cramping or diarrhea, but they are not life-threatening.

Types of Food Allergies

More than 170 foods are known to cause food allergies. However, nine foods account for the majority of all food-allergic reactions in Americans:

  • Milk
  • Egg
  • Peanuts
  • Tree nuts (including almonds, walnuts and cashews)
  • Fish (including pollock, salmon, cod, tuna, snapper, eel and tilapia)
  • Crustacean shellfish (including shrimp, lobster and crab)
  • Soy
  • Wheat
  • Sesame

Eating with Food Allergies

People with food allergies need to avoid foods that make them sick. But navigating menu items and dishes that include a combination of ingredients can be difficult at times. Allergy-triggering foods may be prepared on the same surfaces or with the same utensils as ingredients that are normally okay for that person. Through cross-contact, a food allergen can sneak into what may otherwise be a safe food.

If you have a food allergy, be sure to speak with whoever is preparing your food to inform them of your allergy and ask them to be especially careful when preparing your food.

Talk with your day care, school and workplace. Make sure the teachers, nurse and administrators at your child's school or day care center are aware of your child's food allergies and that they know how to respond to adverse reactions your child may experience. Similarly, inform your coworkers of allergies you have. Some people are familiar with food allergies and know what to do if a person has a reaction; others may not and will need your help in keeping your risk for exposure low.

Follow these tips whether you have a food allergy or intolerance.

  1. Meet with a registered dietitian nutritionist. An RDN can help you understand which foods and beverages are safe to consume and how best to avoid items that may cause a reaction. When foods or food groups need to be avoided, your eating plan may be lacking in important nutrients, such as certain vitamins and minerals. An RDN can help ensure you get the nutrition you need for your health and lifestyle. Find a registered dietitian nutritionist in your area.
  2. Learn about ingredients in foods. Eggs, wheat, milk and other food allergens are often called other names. To help avoid the major food allergens, the U.S. Food and Drug Administration has mandated food companies specify on product labels if any of the nine major food allergens (listed above) are contained in the food or beverage. An RDN can guide you on how to read the ingredient list on a Nutrition Facts label.
  3. Read labels carefully. Manufacturers can change ingredients of products without notice, so double-check ingredient lists every time you buy a food or beverage, even if it is a familiar one. Cosmetics and beauty products also may contain common allergens such as sesame, milk, egg, wheat and tree nuts.

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