Skip to Main Content

If you feel you have been infected with Coronavirus, please call your physician's office first before coming to The Iowa Clinic. 

What to Eat and What to Avoid When You Have a Food Allergy

The safest way to prevent an allergic reaction and manage your symptoms is to stay away from the food that causes it.


Daycares and schools are more focused on food allergy awareness and prevention. But food allergies aren’t just for kids.

While many food allergies begin in childhood, you can develop one at any age. Half of food-allergic adults developed their allergies after they grew up. And when you find out that you’re suddenly allergic to something you’ve been eating your entire life, you have one question:

What can I eat?

Avoid the food, avoid the allergic reaction. That’s the simplest way to prevent your symptoms. The problem is, there’s nothing simple about it.

Many food products and mealswoman-reading-allergens-food-label contain ingredients you’d never expect — or they’re cross-contaminated by allergens in the production or cooking process. Navigating ingredient labels and menus is a chore. But you have to be diligent in your research and ask questions at restaurants to avoid your food allergy symptoms.

Fortunately, all products regulated by the Food and Drug Administration (FDA) are required to list the major food allergens on their labels:

  • Shellfish
  • Tree nuts
  • Peanuts
  • Fish
  • Wheat
  • Milk
  • Eggs
  • Soy

There are more than 170 different foods that have been reported to cause an allergic reaction. These eight major allergens are responsible for 90 percent of food allergies. Pore over product packaging before you buy or eat anything. And study up on your allergen to find all the unexpected ways it can crop up in your diet. 

Shellfish Allergy

The most common food allergen for adults is shellfish. Crustaceans like shrimp, lobster and crab cause the majority of reactions, and they’re usually more severe. Mollusks are another type of shellfish that includes clams, mussels, oysters and scallops. An allergy to one of these is rare. Most people who are allergic to crustaceans are not also allergic to mollusks, so food manufacturers aren’t required to include mollusks on food labels.

You probably want to avoid seafood and sushi restaurants entirely if you have a serious shellfish allergy. And if you’re a fan of Asian dishes, talk to someone at the restaurant before eating any Chinese, Thai, Japanese, Vietnamese or Korean food. Because of the probability of cross-contamination, your allergist might also recommend you avoid eating mollusks at restaurants.

What You Can Eat

What You Must Avoid

Kosher foods – Shellfish is not part of the diet so kosher-certified products are safe.

Barnacles
Crab
Crawfish
Krill
Lobster
Prawns
Shrimp

Tree Nut Allergy

Tree nuts cover a wide variety of nuts, including snacking favorites like almonds, pistachios and cashews. Similar to shellfish allergies, when you’re allergic to one type of tree nut, there’s a good chance you’re allergic to another.

Peanuts are different — they don’t grow on trees. But they’re often manufactured and processed in the same facilities, so you have to be careful if you replace your tree nut products with peanut products. Many pastries, desserts and ice creams contain tree nuts, forcing you to steer clear of bakeries and ice cream parlors.

What You Can Eat

What You Must Avoid

Peanuts
Peanut butter

Peanut oil
Peanut products
Coconut oil
Coconut butter
Sunflower butter
Sunflower oil

Almond paste
Almonds
Beechnuts
Brazil nuts
Butternuts
Cashews
Chestnuts
Hazelnuts
Ginkgo nut
Hickory nut
Macadamia nut
Marzipan
Nut extract
Nut butters
Nut milks
Nut oils
Pecans
Pesto
Pine nuts
Pistachios
Pralines
Shea nuts
Walnuts

Peanut Allergy

Schools, daycare centers and other kid-friendly places are often peanut-free. You lose that protection when you reach adulthood — even though 80 percent of people don’t outgrow their childhood peanut allergy. There’s a chance you’re also allergic to tree nuts, so you need to work with your allergist to determine if you need to avoid nuts of all kinds.

Peanuts are commonly used in African, Asian and Mexican cuisine. Take great care to avoid foods that contain or came in contact with peanuts in these dishes.

What You Can Eat

What You Must Avoid

Coconut butter
Coconut milk
Coconut oil
Nut butters
Nut extracts
Nut milks
Nut oils
Sunflower butter
Sunflower oil
Tree nuts

Beer nuts
Mixed nuts
Peanut butter
Peanut flour
Peanut oil
Peanuts

Fish Allergy

Swimming creatures with fins and not shells are also common allergens. Salmon, tuna and halibut are the most likely culprits. Unlike the tree nut-peanut connection, fish allergies and shellfish allergies are not linked. Being allergic to fish does not increase your odds of being allergic to shellfish. It does make you more likely to have an allergy to another type of fish.

Seafood and sushi restaurants should be placed on your “Do Not Go” list. You should also be wary of supplements, which are not regulated by the FDA. Omega-3 comes from fish oil and it’s commonly added to all kinds of products.

What You Can Eat

What You Must Avoid

Crab
Lobster
Shrimp
Mussels
Clams
Oysters
Scallops

Anchovies
Caviar
Fish flavoring
Fish flour
Fish oil
Fish sauce
Fish stock
Freshwater fish
Omega-3
Roe
Saltwater fish
Seafood flavoring
Shark
Sushi

Wheat Allergy

A wheat allergy is what most people think of as a gluten allergy. Wheat allergies are more common in kids. Most children grow out of it by their third birthday.

People with celiac disease have a problem ingesting gluten from wheat, barley and rye, but not from other grains. If you have a wheat allergy, you do not always have to follow a gluten-free diet. You just have to avoid wheat. Wheat is the most commonly used grain in the U.S., which means you have to search for a lot of substitutes when selecting baked goods and processed products.

What You Can Eat

What You Must Avoid

Amaranth
Barley
Corn
Oats
Quinoa
Rice
Rye
Tapioca

Bread
Bread crumbs
Bulgur
Croutons
Couscous
Crackers
Farro
Flour
Pasta
Seitan
Spelt
Sprouted wheat
Wheat and wheat gluten
Wheat grass
Whole wheat berries

Milk Allergy

Often confused for lactose intolerance, a milk allergy is an actual immune response to milk and not a problem digesting the lactose in milk. It’s basically a dairy allergy — you’re allergic to all foods that contain cow’s milk.

Milk allergies are most common in infants. Children can outgrow it. But if they have seasonal allergies, asthma or one of the other common food allergies, it’s more likely to last into adulthood. If you still have a milk allergy as an adult, you have to follow a dairy-free diet and may have to avoid goat’s milk too.

What You Can Eat

What You Must Avoid

Almond milk
Cashew milk
Coconut milk
Coconut butter
Margarine
Mayonnaise
Non-dairy creamer
Non-dairy yogurt
Oat milk
Rice milk
Sorbet
Soy milk
Vegan food products

Butter
Buttermilk
Cheese
Cream
Custard
Pudding
Ranch dressing
Sour cream
Whey and whey protein
Yogurt

Egg Allergy

Egg allergies are second to only milk allergies in children but are extremely rare in adults. Most kids outgrow an egg allergy by the time they turn five. This allergy is specific to chicken eggs but most people also have to avoid all bird eggs.

Eggs are found in a surprising number of products. Many kinds of ice creams, pasta and foamy coffee drinks have egg in them. You need to seek out egg-free alternatives.

Eggs are also a core ingredient in baked goods. The amount is usually minimal, though. So if you have a mild allergy, you might be fine eating most baked goods with your allergist’s permission. You can always swap them out for different binding ingredients in your own baking if you need to.

What You Can Eat

What You Must Avoid

What You Can Substitute

Vegan egg substitutes and food products

Egg whites
Egg beaters
Eggs
Eggnog
Mayonnaise
Meringue

Applesauce
Arrowroot
Aquafaba
Baking soda + vinegar
Buttermilk
Chia seeds
Flaxseed
Mashed banana
Nut butters
Silken or soft tofu
Soy
Yogurt

Soy Allergy

Soy is another common childhood allergy. Soy allergies appear early on in babies and go away before kindergarten. Soybeans are a legume like peanuts but the allergies aren’t related. Having a soy allergy does not make you any more likely to be allergic to peanuts, beans, peas or lentils.

While soybeans aren’t a staple of the American diet, they’re found in the vast majority of processed foods — much like wheat, milk and eggs. In many cases, a soy protein known as lecithin is used as a food additive and stabilizer. Most people can safely eat products with lecithin without experiencing a reaction. Read the label closely to know which soy ingredient is present.

What You Can Eat

What You Must Avoid

Vegetable-based meat alternatives
Almond milk
Coconut milk
Cashew milk
Cow’s milk
Goat’s milk
Rice milk

Asian cuisine
Edamame
Miso and miso soup
Soy milk
Soy sauce
Soybeans
Tempeh
Tofu

How do you know if you have a food allergy?

Get tested. It’s the only way to know for sure.

Even if you think you have symptoms of a food allergy, there’s a 50 percent chance you’re wrong. A 2019 study in the Journal of the American Medical Association found that while 10 percent of American adults have a food allergy, twice as many people thought they had one.

If it’s not an allergy, it could be a lesser sensitivity or intolerance. Your diet and dining out options wouldn’t need to be nearly as restrictive. Before you start altering your eating habits, consult an allergist for testing to figure out which foods you can carry on enjoying and which ones you actually need to avoid.

Back to top