Everything You Need to Know About Elimination Diets

Mercey Livingston
Medically Reviewed
February 5, 2020

Doing an elimination diet might sound intimidating at first, even insurmountable. Can you really take out a bunch of foods from your diet that you’ve been eating your whole life? Maybe it sounds cruel, but there’s a reason elimination diets have been known as the first step in many healing protocols or functional medicine treatment plans for years. In fact, elimination diets have been around since 1926 .

Today they are mainstays of many many doctors and nutritionists because research has found that food allergies or sensitivities can be linked with a wide variety of medical concerns and symptoms, especially autoimmune diseases and digestive issues, hormonal issues, headaches, migraines, and more.

So what is the purpose of an elimination diet? While “diet” is part of the term, elimination diets have little to do with weight loss. They’re all about finding what foods work the best for your body. For more insight, Christina Vittas, a former health coach at Parsley Health LA, explains what you need to know about doing an elimination diet below.

What is an elimination diet?

At its core, an elimination diet involves eliminating certain food groups or specific foods from your diet for a short time in order to pinpoint food sensitivities and relieve related symptoms.

The elimination diet requires you to remove food groups or certain foods that are most commonly known to trigger food sensitivities and digestive issues and exacerbate symptoms related to autoimmune or other medical conditions.

According to Vittas, a typical elimination diet meal plan will target these main foods and food groups:

  • Soy
  • Dairy
  • Gluten
  • Eggs
  • Nightshades
  • Corn
  • Peanuts
  • Refined sugar
  • Alcohol
  • Caffeine
  • Sometimes all grains (especially in autoimmune cases)

“When you do this it helps you identify if and which foods may be exacerbating symptoms. More broadly if you’re eliminating foods that trigger inflammation in the body, you can get rid of many symptoms that have inflammation at their root,” she explains.

At Parsley Health, the elimination diet is an important part of identifying potential inflammatory triggers, and then using that information to work with your doctor and health coach on how best to move forward.

How to do an elimination diet and who should try it

Your doctor, nutritionist, or health coach may ask you to do an elimination diet if you are experiencing symptoms that could be associated with inflammation, or other tricky symptoms that you are having trouble pinpointing what might be causing them. They will evaluate your symptoms and recommend a period of time that you should do the diet. In general, this is a minimum of 3 weeks, but sometimes it can be longer.

“The duration depends on two things: willingness and severity of their symptoms. If someone is really struggling, it can be better to extend that time to 4-6 weeks. And if someone has less serious symptoms, 3 weeks is usually enough to get a baseline understanding,” says Vittas.

Once you complete the elimination diet period recommended by your doctor or health coach, you then start what’s called the reintroduction phase. This phase is the most important because it is when you gather data and pinpoint which foods may be triggering your symptoms.

“Reintroduction takes a lot of patience because you only want to bring in one food group at a time,” says Vittas It’s important that you do the reintroduction phase correctly since if you start bringing back the foods all at once, you’ll lose the purpose of the whole process, which is to find which specific foods give you trouble.

When you reintroduce a food group, like dairy, you start with just a small amount or about ¼ of a normal serving of the food on the first day. Then on the second day, you do half a serving, and work up to a full serving of that food on the third day. After day 3, you go back to the elimination diet for 3 more days to wait to see what or if any symptoms show up.

Why three days? “Food sensitivities are different than food allergies. With food allergies you’re getting a more immediate reaction, but with food sensitivities it can take up to 72 hours to have a reaction,” says Vittas.

You’ll continue this process for each eliminated food or food group and assess any reactions you have. Because the process can be tricky, working with a doctor, nutritionist, or health coach can help you stay on track. It’s also a good idea to keep a journal during this time to log any symptoms.

Even though elimination diets help many different people, they are not for everyone. “We recommend it for almost everyone, but we also take into account people’s willingness,” says Vittas “Sometimes people aren’t really willing to do it or they don’t have the time or space. So we might start with something more approachable instead of a full elimination diet. So it could be starting with cutting out something like dairy, and trying that first,” says Vittas.

At Parsley Health, doctors and health coaches do not recommend elimination diets to someone who has a history of eating disorders since the diet can trigger feelings of over restriction.

Does food sensitivity testing work?

If you’re wondering if there are any shortcuts, the answer is yes and no. Even though food sensitivity tests are helpful, they aren’t always foolproof. While the tests claim to pinpoint really specific foods, which can be helpful, they’re not always accurate.

“There are some people who don’t want to do an elimination diet or can’t, but they suspect they are reacting to foods,” says Vittas. For these cases, a food sensitivity blood test may be able to give you a starting point to see what’s going on. But Vittas warns they’re not a perfect science and you can get a false positive or a false negative. That’s why she prefers an elimination diet.

“The body doesn’t lie,” she says. “If you eat something and it triggers a reaction (i.e. a flare up of any preexisting symptoms) then that feedback is ultimately going to trump what any food sensitivity panel says,” says Vittas.

How an elimination diet fits into treatment

It’s important to see an elimination diet as a helpful tool that can help you and your doctor optimize your health. The results you can expect with an elimination diet vary because everyone is so different—you could even find food is not a trigger for your symptoms or that other things are contributing to your symptoms in addition to food.

Regardless of what you find from doing an elimination diet, removing the food is only one part of the treatment, explains Vittas. “You also have to do the underlying work to heal.”

Oftentimes, this underlying work involves evaluating your gut health and healing and strengthening it. “If you’re someone that has a hyperpermeable gut, and you remove the food triggers, that’s great, but if you’re not reducing the permeability of the gut, then you’re going to run into the same issue later down the line,” she says.

Vittas explains that sometimes once you actively heal the gut, foods that bothered you before can be tolerated again, which is pretty encouraging. Remember, just because you eliminate certain foods now doesn’t mean you can never enjoy them again (whether that’s now or months later). Food sensitivities can and do change over time, which is why it’s important to find an eating plan that works for you in conjunction with your doctor and health coach and evaluate it periodically.

Mercey Livingston

Mercey Livingston is a health and wellness writer and certified Integrative Nutrition Health Coach. She is passionate about translating expert and science-based wellness advice into accessible and engaging content. Her work is featured on Well+Good, Women's Health, Business Insider, and among others. When not writing, she enjoys reading, trying out new recipes, and going to new workout classes all over New York City.

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