How to Do an Elimination Diet and Why Everyone Should Try One

Do you have a food intolerance? You may have mystery issues that seem to come and go, or lingering brain fog and fatigue that you just can’t shake. The answer to those nagging problems might be on your plate. Learning how to do an elimination diet may be the key to uncovering underlying food sensitivities.

Estimates vary widely, but experts say that as much as 20% of the population suffers from a food intolerance.^[1] People are becoming more and more aware of intolerances to common foods like gluten and lactose, and those who identify their food sensitivities can see amazing results simply by avoiding those foods.

An elimination diet is an easy way to identify food intolerances. If you’re wondering how to do an elimination diet, you’re not alone. Once you understand the basic premise, it’s easy to put together an elimination diet meal plan.

What is an elimination diet?

An elimination diet is a way to test yourself for food sensitivities.

There are different types of elimination diets. For example, some people feel better after eliminating gluten and dairy for a few weeks, while others might follow a stricter FODMAP elimination diet to manage symptoms of irritable bowel syndrome (IBS). Talk to your doctor before you try an elimination diet.

In general, you want to completely avoid common foods known to cause sensitivities, then reintroduce the eliminated foods into your diet one at a time. The goal is to identify whether certain trigger foods might be causing inflammation, headaches, skin issues or other side effects.

By eliminating that food from your diet for a period of time, you might discover that you sleep better, think more clearly and just feel more like yourself. This process may initially feel complicated or restrictive, but it could lead to improved overall health and wellness in the long run.

For many people, an elimination diet is the gold standard to identify the foods that don’t work with their system. Maybe you don’t need to abandon carbohydrates—maybe you just need to cut back on sugar or gluten to feel your best. Good news: You can find a delicious variety of foods, snacks and supplements made without gluten, artificial sweeteners, soy or dairy, like Bulletproof Collagen Protein Bars.

Signs of food sensitivities

You might think of food allergies as the instantaneous, life-threatening type. Typical to allergens like shellfish and peanuts, this allergic response causes a massive release of histamines in the body, leading to swelling of the lungs and throat.^[2]

However, not all food allergies and intolerances are this severe. Reactions to allergens can range, and in some people, signs of food intolerances are barely noticeable or not noticeable at all.

In fact, you might blame your issues on something else entirely. Gluten, for example, can cause some people to simply feel tired, which may not immediately be a red flag. Some of these less noticeable reactions to foods include:

• Dry skin
• Gastrointestinal issues, such as bloating, constipation and diarrhea
• Itching
• Digestive upset
• Fatigue
• Headaches
• Stomach aches
• Joint aches and pains
• Migraines

How your body reacts to different allergens is based on your individual chemistry. The key is to be mindful—take the time and pay attention to how your body reacts to what you eat.

What can you eat on an elimination diet?

The trickiest part about an elimination diet is deciding which foods are most likely to cause a reaction. Luckily, that part is done for you. The Bulletproof Diet Roadmap takes all the guesswork out of how to do an elimination diet.

The Roadmap takes into account the likelihood that a food or food group may cause inflammation or reactions in your body. Eat from the Roadmap’s green zone during your elimination period. This elimination diet food list allows nourishing choices like grass-fed, organic meats, most plant-based whole foods and some plant-based products like MCT oil (which comes from coconuts). Fill your plate with quality proteins, healthy fats and vegetables in the green zone.

Here’s how to do an elimination diet, using the Bulletproof Diet Roadmap as a cheat sheet:

1. Eat exclusively from the green zone for at least two weeks, but skip eggs and dairy for now.
2. Make a list of foods you want to test for your body’s reaction.
3. To begin the reintroduction phase, choose one test food to reintroduce into your diet. Eat it with abandon for three days.
4. Take detailed notes on how you feel during this reintroduction, and make a point to notice everything you’re feeling. No matter how small it seems, write everything down.
5. After day three, go back to only green zone foods for three to four days, until you’re feeling back to normal again. Then repeat steps 3-5 until you’re through your entire list of test foods.

Foods to avoid during an elimination diet

Wondering which common foods and food groups to avoid during your elimination diet? Here’s a handy elimination diet food list cheat sheet of food groups to steer clear of:^[3]

• Dairy products (including milk, ice cream and sour cream)
• Eggs
• Gluten (including barley, oats, rye and wheat)
• Fish and shellfish
• Nightshades (tomatoes and onion)
• Citrus (contain high amounts of potentially reactive antioxidants)
• Legumes (including soy-based products, beans, lentils and peas)
• Peanuts
• Tree nuts
• Corn
• Non-organic beef, which may contain the biogenic amines histamine, tyramine, octopamine and phenylethylamine known to potentially cause reactions
• Sweets or candy containing refined sugar, corn syrup, artificial colors and flavors

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Sample elimination diet meal plan

Double-check your food labels when you start your elimination diet. Some foods may seem like they fit your goals until you read the ingredients. Not sure where to start? Here’s an example of what a basic elimination diet meal plan could look like for the day. Of course, this is just one example of what you can enjoy during an elimination diet, but you’ll notice elimination diet meal plans are free of the potentially inflammatory foods above.

• Breakfast: If you’re drinking coffee on your elimination diet, start your day with Bulletproof Coffee, which is full of quality fats that help you feel alert and satisfied. No caffeine? Try a satisfying Keto Hot Chocolate instead.
• Lunch: For lunch, whip up a refreshing Low-Carb Thai Salad With Grilled Steak, which incorporates crisp fresh veggies, coconut oil or Bulletproof Grass-Fed Ghee and grass-fed top-sirloin in a spicy Asian-inspired marinade.
• Snack: Throughout the day, snack on foods like crunchy veggie sticks and sweet potato chips. Check out these other Whole30 snacks for inspo.
• Dinner: Round out the day with this nutrient-rich Slow-Cooker Beef Stew recipe, which you can prepare ahead of time and simmer all day long. Serve with quinoa, brown rice or buckwheat, which are elimination diet-friendly, gluten-free side dishes.

How long does the elimination diet take to work?

This depends on your body and the specific elimination diet you choose. Some people feel changes within the first few days, but it can also take several weeks or even several months on an elimination diet to notice a difference.

Here are two examples:

• Whole30 is an elimination that cuts out common trigger foods, like ultra-processed foods, artificial additives, grains, dairy and legumes. It’s meant to last a full 30 days.
• The FODMAP elimination diet can last three to four months. A FODMAP diet cuts out foods that are high in certain sugars (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) that can irritate your digestive system. It includes an initially low-FODMAP diet elimination phase and a long reintroduction process when eliminated foods are slowly re-incorporated.

But whether you go with Whole30, FODMAP elimination diet or some other plan, it all depends on your body. There’s no one-size-fits-all period of time for everyone.

Also, keep in mind that it takes time for your body to flush the trigger foods from your system, and even longer for your body to stop reacting. If your reactions don’t improve right away, keep going—and stay in communication with your healthcare provider.

While an elimination diet can be helpful for some people, it may not work for everyone, and food may not be the problem. Your doctor or healthcare provider can offer specific medical insights and run tests for specific allergens. It may also help to consult with a nutritionist or registered dietitian.

Why everyone should do an elimination diet at least once

Even if you don’t think you have any food sensitivities, it’s a good idea to do an elimination diet at least once. Keep reading to find out why.

More energy and mental clarity

If your body is reacting to something you eat on the regular, chances are you don’t know how potentially good you can feel because your body is in reaction mode every single day. After the initial detox period of a few days, many people feel more energy and clarity than ever during an elimination diet.

If you come out of the initial elimination diet slump feeling like a superhero, that’s a big indication that certain foods affect you. You’ve got little to lose for what might be an incredible gain in performance.

Identify foods that cause inflammation

Between stress, pollutants, chemicals in our food and water and other environmental stressors, modern society deals with a lot of inflammation.

Your inflammatory response is an important part of your immune system, and you need it to rally when necessary. You also need it to turn off when the work is done. If your immune system stays engaged long-term, you have chronic inflammation. Over time, it can chip away at healthy cells and tissues until things have gone too far, and you end up with real damage.

Chronic inflammation can be subtle, to the point that it can be imperceptible to you. An elimination diet will reveal whether a food is contributing to chronic inflammation.

If you’re experiencing low-level issues all the time, like feeling tired, foggy, achy or itchy, you get used to it. You might even think it’s normal. When you feel amazing for a few weeks, red flags are more noticeable when they come back again after you eat the food you’ve been avoiding.

When you bring food back, take notice of everything happening in your body and mind. Your body has a way of making clear when something isn’t working well. All you need to do is pay attention.

Here’s an important caveat: Elimination diets are restrictive by nature. If you have a history of eating disorders, work with a physician before you try any restrictive diets.

Or, you can take the shortcut

In addition to starting a conversation with your doctor, there are several tests you can take to see if you have food sensitivities. Two of the more reliable ones include:

• EverlyWell: EverlyWell involves pricking your finger and dotting a card with a few drops of blood to test IgG reactivity (a measure of an immune response) for 96 different foods. (Enter BULLETPROOF at checkout for 15% off of your order.)
• Viome: Viome combines information from a microbiome test with a metabolic test to see how your body and the flora in your digestive system interact with specific foods. You’ll get a personalized plan to stay balanced and run at maximum power, without being slowed down by food sensitivities.

Maybe you have unexplained problems, or you suspect you’re not performing as well as you could. After a short experiment, you’ll have a fairly good idea of what you can eat and what to avoid. It’s not as difficult as it seems. Go for it. You’ll be glad you did! Your health and wellness should be a top priority, after all.

This is an update of an article originally published November 2018.