Why and How To Start an Elimination Diet

Sometimes, the foods you love don’t love you back. When your body responds to your favorite foods with symptoms like bloating and diarrhea, you may start regretting some of your food choices.

But which foods are at the root of your issues? It’s not always easy to figure out. Enter the elimination diet, which may help you identify the offenders.

Registered dietitian Sharon Jaeger, RD, walks you through the steps of starting an elimination diet to help pinpoint the culprit of your concerns.

Why choose an elimination diet?

An estimated 20% of the population has a food intolerance or sensitivity, but they’re not easy to diagnose. If you’re experiencing frequent tummy troubles, your healthcare professional is likely to recommend an elimination diet to nail down the cause of your symptoms.

“Elimination diets are the gold standard for figuring out which food don’t agree with you,” Jaeger says.

Benefits of an elimination diet

During an elimination diet, you stop eating one or more potential problem foods for several weeks. As part of this process, you’ll keep a food journal to document what you eat and how it affects you.

“Once you stop consuming a food that you’re sensitive to, the inflammation in your gut and your immune system will calm down, repairing any inflammatory response that those trigger foods have caused,” Jaeger explains.

Then, as you slowly reintroduce those foods into your diet, you keep track of how you feel as they return. The hope is that your healthcare provider can identify patterns that indicate cause and effect.

Food allergy vs. food intolerance

It’s important to know that food allergies aren’t the same as food intolerances or sensitivities. “There are a lot of food foundations to people’s health issues, and many of them stem from these three things,” Jaeger notes.

• Food allergy: This potentially life-threatening response happens when your body overreacts to the proteins in specific foods. Allergic reactions can include skin irritation, hives, rashes, itchiness, swelling and anaphylaxis.
• Food intolerance: When your body can’t properly break down a certain food or ingredient, you might experience GI issues like diarrhea, gas and bloating. Some intolerances can cause cold-like symptoms.
• Food sensitivity: Sometimes lumped in with intolerances, sensitivities are due to an imbalance of the bacteria in your gastrointestinal tract (your gut). Symptoms can include GI issues, fatigue, joint or muscle pain, headaches and brain fog.

Common foods that cause digestive issues

Eight types of food account for about 90% of all food allergies — and those same foods are often the source of intolerance in people who aren’t allergic to them but still have a sensitivity.

• Eggs.
• Fish.
• Milk.
• Peanuts.
• Shellfish.
• Soy.
• Tree nuts, like pecans, almonds and walnuts.
• Wheat.

Other foods and ingredients can cause issues, too. Some other intolerances and sensitivities include:

• Alcohol.
• Corn.
• Histamines, naturally occurring chemicals in foods like cheese, pineapples, bananas, avocados and chocolate.
• Gluten, a protein food in wheat, rye and barley.
• Fish and shellfish.
• Fructose, a sugar in fruits and some vegetables.
• Lactose, a sugar found in milk and dairy products.
• Nightshades, foods and spices containing chemical compounds called alkaloids.
• Some food additives, like monosodium glutamate (MSG).
• Sulfites, compounds in red wine and beer that are also added to certain foods.

How to start an elimination diet

“The elimination diet really homes in on food sensitivities and intolerances, removing the most common trigger foods we see in people,” Jaeger says. She walks you through the steps.

1. Consult with your healthcare provider

The most important thing to know before starting an elimination diet is that you should only do it with the guidance of a medical professional.

• You could have a serious medical problem: Going it alone can cause you to go without treatment for underlying issues like celiac disease and inflammatory bowel disease. “Without appropriate care, you could be delaying treatment or masking symptoms by changing your diet,” Jaeger says.
• You could end up lacking key nutrients: “If you don’t have the appropriate person helping you, you could end up with a whole host of other medical problems because your diet is deficient,” she warns.

2. Remove possible triggers from your diet

This is another reason to work with a professional: You don’t need to remove every single possible trigger food. Based on your symptoms, a physician or dietitian can determine which foods are likely to be your trigger foods, creating a tailored elimination diet plan that’s designed to get results with the least amount of difficulty for you.

“Based on your symptoms, your health history and any diagnoses you might have, your practitioner will determine which key foods you should remove,” Jaeger says.

3. Follow the prescribed diet for one to two months

It takes time for your elimination diet to show results. You’re not removing all these foods from your diet forever, but you do need to remove them for enough time to allow your body to respond.

“In general, the idea is that you remove a certain set of foods for a period of time, say four to eight weeks,” Jaeger explains.

4. Keep a food journal

This isn’t just to keep track of the food you eat. It’s also to keep track of the symptoms you experience (or don’t!), the moods you feel, the colors of the foods you’re eating and anything else that seems relevant.

“You can keep track of the colors of the foods you’re eating, how well you’re sleeping, how you’re managing your stress,” Jaeger says.

Sometimes, stress and anxiety can make food issues worse (and being calm and relaxed can make them better), so you may want to make note of what you’re doing and how you’re feeling on any given day.

5. One at a time, add each food back in

“After a prescribed period of time, your practitioner will work with you to slowly and methodically add each food back in, one at a time, to see if you get any symptoms from that food,” Jaeger explains. “That’s how we can identify your trigger foods and whether that healing process has worked.”

After weeks without your favorite foods, you may be eager to try to add some of them back into your diet. But Jaeger warns that the elimination diet calls for slow and steady reintroduction.

“If you don’t do your reintroductions slowly enough, you’re not going to be able to figure out what those trigger foods are,” she says. “Elimination isn’t easy, and you do not want to have to repeat this just because you didn’t pace yourself.”

To learn more from Sharon Jaeger on this topic, listen to the Health Essentials Podcast episode, “Why and How to Try an Elimination Diet.” New episodes of the Health Essentials Podcast publish every Wednesday.