Surprising Foods You Shouldn't Eat if You're AIP
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Surprising Foods You Shouldn't Eat if You're AIP

March 11, 2022
New Africa/
New Africa/

Reviewed by Dr. Mark J. Smith on March 7, 2022

Trying the AIP Diet? Most foods in the elimination phase are already not Paleo, but beware! There are a few Paleo-approved foods you should avoid for a short while if you have an autoimmune disease.

The Autoimmune Protocol Diet, or AIP for short, is a type of elimination diet. It was created to help reduce inflammation, pain, fatigue, and other symptoms of autoimmune disease. [1]

An AIP diet is built around the premise that certain foods can irritate the gut and trigger an autoimmune response that can then induce symptoms.

If you are already following The Paleo Diet®, you’ve essentially cut back on (or completely eliminated) most foods that could be harmful, like grains and refined sugar. However, there are a few extra Paleo-approved foods that you should steer clear of if you’re AIP. Here’s what they are, and why you should avoid them.

How does the AIP Diet work?

The AIP diet works in phases. The first phase of the AIP diet eliminates specific foods for 30 to 90 days, or whenever symptoms seem to improve.

The second phase gradually reintroduces those foods one at a time in order to identify which foods may be causing a response and/or symptoms.

Here are a few of the non-Paleo food groups that are eliminated when you go AIP:

  • Grains. Regardless of whether they’re whole (with the entire grain kernel intact) or refined (processed so that fiber, iron and vitamins are stripped away), grains are off the table on AIP.[2] This is because grains, and especially wheat, are not easily tolerated by many, and they contribute to chronic inflammation and autoimmune diseases. [3]
  • Dairy. Anything made with cow’s or goat’s milk, like cheese and yogurt, should be avoided. Dairy contains certain proteins that can trigger inflammation. [4] Plus, lactose intolerance is common!
  • Legumes. Beans, peas, lentils, soy, peanuts, and other legumes are high in lectins. Lectins are anti-nutrients that are hard to digest and may damage the gut barrier, entering into our blood. They can also inhibit the absorption of some minerals. People who may have underlying digestive or autoimmune issues may experience a worse reaction from eating lectin-containing foods than others. [5] Legumes also contain phytic acid that can also decrease the absorption of some minerals and slow digestion. [6]
  • Sugar. Anything made with white cane sugar or high fructose corn syrup, like candy or soda, is off the table on AIP. Sugar is highly processed and devoid of nutrients, and eating too much is associated with inflammation, high blood pressure, weight gain, insulin resistance, and fatty liver disease. [7]
  • Processed foods. These unnatural foods contain refined sugars, sodium, trans fats, artificial coloring and flavorings, processed oils, and more. Frozen meals, instant foods, packaged bread, and fast food are just a few examples of processed foods. They're also generally low in fiber and other nutritional content. They contribute to a host of health issues, especially for those with underlying autoimmune disorders. [8]

Surprising Paleo foods to eliminate on the AIP Diet

Surprising Foods You Shouldn't Eat if You're AIP image

While most of the foods that are eliminated on AIP are also not Paleo, there are a few foods that we eliminate on AIP that are normally Paleo-approved.

Here are a few of these generally healthy foods, and why they should be eliminated in the first phase of the AIP diet.

Egg whites

For many people, eggs are a healthy addition to their diet. But to a person with an autoimmune disease, eggs (especially egg whites) may cause issues.

The enzyme, or protein, in egg whites called lysozyme can cross the gut barrier, carrying with it other proteins that the body will respond to as foreign. Individuals with an autoimmune disease are more sensitive and will have a larger inflammatory response to these foreign proteins attached to lysozymes. [9]

In addition, egg whites have a high incidence of allergy-related symptoms. Although this is mainly about egg whites, egg yolks can also be a common food sensitivity so they too are on the elimination phase of the AIP Diet. Chances are egg yolks will be better tolerated when reintroducing foods than egg whites.

What to eat instead: We have lots of egg-free breakfast recipes to try instead of your daily scramble!. If you’re baking, replace eggs with coconut oil, applesauce, pumpkin puree, or avocado.


Although eggplant is highly nutritious food, it's on the elimination list of the AIP Diet because they are considered a nightshade plant. Nightshades contain certain compounds (like lectins, saponins and capsaicin) that may cause irritation in the gut and worsen issues from an already present autoimmune disease.

However, there is great debate on whether these highly nutritious nightshades actually induce inflammation at all. This is why the elimination phase of the AIP diet is so important. If they cause no issues, nightshades should be reintroduced in the second phase of the diet and not avoided. [10]

What to eat instead: Try using zucchini or yellow squash in place of eggplant.


Just like eggplant, peppers are considered nightshades. Yes, this includes both bell peppers and hot peppers! Seasonings such as cayenne, paprika and red pepper flakes should also be avoided.

What to eat instead: Try using yellow squash in place of bell peppers, or use ground ginger as a seasoning.


Sadly, tomatoes are also nightshades, meaning they should also be avoided on the elimination phase of the AIP Diet for the same reasons.

What to eat instead: Depending on what you’re making, veggies like cucumber, carrots, celery or zucchini can be a good stand-in. You can also swap your tomato sauces for olive oil and black pepper.


For most people, bananas are not an issue. But if you have autoimmune issue, it might be worth eliminating to see how your body responds. The pulp of ripe bananas contains a molecule called thaumatin-like protein that may have similar properties to lectin. These molecules may also be responsible for allergies. [11, 12]

What to eat instead: You can snack on any other fruit. If you’re baking banana bread or something similar, try applesauce, avocado, or pumpkin puree in place of bananas.

The Bottom Line

While most foods that are eliminated in the first phase of the AIP diet are already not Paleo, there are a few extra foods you’ll want to avoid – like nightshades, eggs, and bananas.

Remember, the elimination phase is only temporary! The end goal is to give the body time to heal, to eventually tolerate some foods, and to pinpoint foods that may be a permanent issue. The reintroduction phase will look different for everybody, so be patient with yourself!

Note: It is recommended to visit a registered dietitian nutritionist before beginning any type of elimination diet. Professional support can ensure you are following the diet correctly and that all of your essential nutritional needs are being met.

How to Start an Autoimmune Protocol Diet


  1. Leech B, McEwen B, Sekyere EO. Diet, digestive health, and autoimmunity: The foundations to an autoimmune disease food pyramid—part 2. Altern Complement Ther. 2020;26(4):158–67.
  2. What foods are in the Grains Group? [Internet]. USDA MyPlate. [cited 2022 January 28].
  3. Punder K, Pruimboom L. The Dietary Intake of Wheat and other Cereal Grains and Their Role in Inflammation. Nutrients. 2013 Mar. 5(3): 771-787.
  4. Campbell T, MD. Autoimmune Disease: Genes, Infection, Environment & Gut. [Intermet] Center for Nutrition Studies. 2020 [cited 2022 February 1].
  5. Lectins [Internet]. Harvard School of Public Health/The Nutrition Source. [cited 2022 February 4].
  6. Are Anti-Nutrients Harmful? [Internet]. Harvard School of Public Health/The Nutrition Source. [cited 2022 February 5].
  7. The sweet danger of sugar [Internet]. Harvard Health Publishing. 2022 [cited 2022 February 4].;
  8. Fuhrman J, MD. The Hidden Dangers of Fast and Processed Food. Am J Lifestyle Med. 2018 Sept-Oct; 12(5): 375-381.
  9. Sahin O, Ziaei A, Karaismailoglu E, Taheri N. The serum angiotensin converting enzyme and lysozyme levels in patients with ocular involvement of autoimmune and infectious disease. BMC Ophthalmol. 2016; 16: 19.;
  10. What’s the Deal With Nightshade Vegetables? [Internet] 2019 [cited 2022 February 5].
  11. Barre A, Peumans WJ, Menu-Bouaouiche L, Van Damme EJ, May GD, Herrera AF, Van Leuven F, Rouge P. Purification and structural analysis of an abundant thaumatin-like protein from ripe banana fruit. Planta. 2000 Nov.; 211(6): 791-9. https://pubmed.ncbi.nlm.nih.go...;
  12. Leone P, Menu-Bouaouiche, L, Peumans WJ, Pavan F, Barre A, Roussel A, Van Damme E, Rouge P. Resolution of the structure of the allergenic and antifungal banana fruit thaumatin-like protein at 1.7-A. Biochimie 2006 Jan.; 88(1): 45-52.

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