In an elimination diet, a food or group of foods is removed from a persons diet for a set period of time. This helps to determine whether specific foods or ingredients in foods contribute to symptoms. Diets are individualized based on each patients history, eating patterns, and overall symptom picture. Elimination diets are, in essence, controlled experiments that focus on changing a single dietary variable at a time.
The process of outlining and then following an elimination diet can take effort and time both for practitioners to explain and for patients to conduct. However, successfully discovering food allergies or intolerances can potentially alter the courses of several diseases and lead to profound symptom improvements.
Serum tests are available to help diagnose adverse food reactions, and these remain controversial given their low accuracy (save maybe for irritable bowel syndrome). Many of these are offered by private laboratories and focus on IgG levels. Food allergies that are IgE-mediated, however, can be accurately assessed through widely available tests. However, the gold standard for food allergies and food intolerances remain placebo-controlled food challenges.
Four key steps are involved in the process.
Step 1: The Planning Phase
Figuring Out Which Food(s) to Eliminate
Begin by ensuring that an elimination diet is clinically appropriate and something that a patient is both willing and motivated to try. A thorough dietary history, which may include a food journal, can help assure clinicians that food restrictions will not contribute to nutrient deficiencies or inappropriate weight loss. Partnering with a registered dietitian trained in elimination diets is also recommended. A dietitian will do a comprehensive nutrition assessment, nutrition-focused physical exam to assess for malnutrition and nutritional deficiencies, and gather and in-depth understanding of the patients' clinical history, preferences, lifestyle, and social factors that impact food choices.
In addition, symptom severity should also be assessed using the Medical Symptom Questionnaire (MSQ). This valuable tool helps identify patterns of imbalance and most problematic symptoms. It should be completed periodically over the course of the intervention to see if the score comes down, revealing symptom improvement. The recommended timepoints to administer the MSQ is before starting the elimination phase, at the conclusion of the elimination phase or prior to reintroducing foods, and at an additional timepoint determined by the clinician after the reintroduction of eliminated foods.
Information to Gather if Food Intolerance Is Suspected[1]
The following lists key points to keep in mind when taking a history from people who may have food intolerances.
- History of present illness
- Relation of symptoms to exercise
- Substance use (caffeine, smoking, alcohol, illicit drugs)
- Life stressors
- Past medical history
- Respiratory allergies
- Chronic respiratory congestion
- Asthma
- Atopic dermatitis
- Infant colic
- Irritable bowels
- Eating disorders
- Food allergies
- Family history
- Food intolerance
- Irritable bowels
- Headache
- Mouth ulcers
- Lab testing
- Previous allergy tests
Some potential risks to consider:
- Elimination diets may exacerbate an existing or activate a latent eating disorder such as anorexia or bulimia nervosa.
- Do not reintroduce foods known to provoke anaphylactic reactions.
- Be wary if one is already malnourished or is at high risk for nutritional deficiencies. This may include the elderly, autistic (given they often already restrict their diets), and those with very limited food resources.
- Given that foods also heal, be cautious of instilling a fear of food.
Consider having one keep a food-symptom diary for a few weeks as a way to better understand what foods may be leading to bothersome symptoms (Referencesample food diary). Here are some questions that often illicit problematic foods:
- What foods do you eat most often?
- What foods do you crave?
- What foods do you eat to help you feel better?
- What foods do you think you might have trouble giving up?
Why might these foods be problematic? One hypothesis is that problematic foods can both trigger an inflammatory process in the gut as well as cause endorphin release in the brain. Endorphins reduce pain, and because they lead to a sense of well-being, their release may cause continued regular consumption of triggering foods.
Once a list of potential problematic foods is generated, decide which foods to eliminate. An individualized elimination diet should be based on ones intuition (what is my gut feeling?), the answers to the above questions, and common provoking foods based on ones disease.
Table 1. Foods That Often Influence Specific Health Problems [1]
| Condition | Foods to consider avoiding |
|---|---|
| Attention deficit hyperactivity disorder (ADHD) | Apples, artificial colors, aspartame (NutraSweet), butylated hydroxyanisole, butylated hydroxytoluene (in packed cereals), benzoates (chewing gum, margarine, pickles, prunes, tea, raspberries, cinnamon, anise, nutmeg), caffeine, corn, dairy products, nitrate and nitrites (preserved meats, like bacon, frankfurters, pepperoni), oranges, propyl gallate, sulfites (dried fruits, mushrooms, potatoes, baked goods, canned fish, pickles, relishes), peanuts, tomatoes |
| Atopic dermatitis | Children: dairy, eggs, soy, wheat Adults: pollen-related foods (fruit, nuts, vegetables) Other considerations: artificial colors, benzoates, berries, citrus, currants, fish, legumes, sulfites, tomatoes, beef, chicken, pork |
| Autism spectrum disorders | Gluten and casein (gluten-free, casein-free diet), food additives, artificial colors |
| Irritable bowel syndrome | Dairy, eggs, wheat Specific carbohydrate diet (Refer to Inflammatory Bowel Disease). |
| Migraine | Caffeine, monosodium glutamate (MSG), processed meats and fish, dairy, nuts, alcohol, vinegar, certain fruits and vegetables (citrus, onions), yeast-risen baked goods, aspartame (NutraSweet) |
| Rheumatoid arthritis | Level 3: The Few-Foods Diet Corn, dairy, nightshade vegetables (bell peppers, eggplant, potatoes, tomatoes) |
| Gastroesophageal reflux disease (GERD) | Alcohol, chocolate, coffee, cows milk, saturated fat, orange juice, spicy foods, tea, tomato juice, peppermint/spearmint |
| Inflammatory bowel disease | Dairy, gluten, yeast, some carbohydrates |
| Serous otitis media | Dairy |
Step 2: The Avoidance Phase
Eliminating Foods: Three Levels[1]
The intensity of the diet depends primarily on how many foods are eliminated at a time.
Low: The simple diet eliminates milk, eggs, and wheat
Elimination of one or a few key foods. Often, these may include milk products and gluten.
- Pros: Better for people at risk of undernutrition or who might have difficulty with adherence.
- The less good: This diet plan will not help to determine if one is intolerant a broader group of foods or food combinations.
Animal proteins
Allowed: Beef, chicken, lamb, pork, turkey
Eliminated: Dairy products, chicken eggs
Grains and starches
Allowed: Arrowroot, barley, buckwheat, corn, millet, oats, rice, rye, sweet potatoes, tapioca, white potatoes, yams
Eliminated: Dairy-based butter and margarines
All fruits, vegetables, salt, spices, sweeteners, and vegetable proteins are allowed.
Moderate: A stricter diet that eliminates several food groups
Pros: High rates of success in determining all kinds of food intolerances without significant nutritional risks.
Cons: Requires significant planning, recording, and time.
Animal proteins
Allowed: Lamb
Eliminated: All others, including eggs and milk
Vegetable proteins
Allowed: None
Eliminated: Beans, bean sprouts, lentils, peanuts, peas, soy, all other nuts
Grains and starches
Allowed: Arrowroot, buckwheat, corn, rice, sweet potatoes, tapioca, white potatoes, yams
Eliminated: Barley, millet, oats, rye, wheat
Vegetables
Allowed: Most
Eliminated: Peas, tomatoes
Fruits
Allowed: Most
Eliminated: No citrus or strawberries
Sweeteners
Allowed: Cane or beet sugar, maple syrup, corn syrup
Eliminated: Any others, including aspartame
Oils
Allowed: Coconut, olive, safflower, sesame
Eliminated: Animal fats (lard), butter, corn, margarine, shortening, soy, peanut, other vegetable oils
Other
Allowed: Salt, pepper, a minimal number of spices, vanilla, lemon extract
Eliminated: Chocolate, coffee, tea, colas and other soft drinks, alcohol
High: A few-foods diets eliminates of all but a few foods
This might be used if one has a long list of potential intolerances and wants to wipe the slate clean.
- Pros: Highest chance for symptom improvement.
- Cons: Greatest potential risks for malnutrition or orthorexia (a fear of food). Requires significant time for the reintroduction process (Reference Step 3: The Challenging Phase, below).
Only the foods listed below are allowed.
- Apples (juice okay)
- Apricots
- Asparagus
- Beets
- Cane or beet sugar
- Carrots
- Chicken
- Cranberries
- Honey
- Lamb
- Lettuce
- Olive oil
- Peaches
- Pears
- Pineapple
- Rice (including rice cakes and cereal)
- Safflower oil
- Salt
- Sweet potatoes
- White vinegar
Table 2. Another Challenge: How to Know Which Foods to Avoid[1]
| If You Are Avoiding | Also Avoid |
|---|---|
| Dairy | Caramel candy, carob candies, casein and caseinates, custard, curds, lactalbumin, goats milk, milk chocolate, nougat, protein hydrolysate, semisweet chocolate, yogurt, pudding, whey. Also beware of brown sugar flavoring, butter flavoring, caramel flavoring, coconut cream flavoring, natural flavoring, and Simplesse. |
| Peanut | Egg rolls, high-protein food, hydrolyzed plant protein, hydrolyzed vegetable protein, marzipan, nougat, candy, cheesecake crust, chili, chocolates, pet feed, sauces. |
| Eggs | Albumin, apovitellin, avidin, barnaise sauce, eggnog, egg white, flavoprotein, globulin, hollandaise sauce, imitation egg products, livetin, lysozyme, mayonnaise, meringue, ovalbumin, ovoglycoprotein, ovomucin, ovomucoid, ovomuxoid, Simplesse. |
| Soy | Chee-fan, ketjab, metiauza, miso, natto, soy flour, soy protein concentrates, soy protein shakes, soy sauce, soybean hydrolysates, soby sprouts, textured vegetable, protein, tofu, whey-soy drink. Also beware of hydrolyzed plant protein, hydrolyzed soy protein, hydrolyzed vegetable protein, natural flavoring, vegetable broth, vegetable gum, and vegetable starch. |
| Wheat | Atta, bal ahar, bread flour, bulgur, cake flour, cereal extract, couscous, cracked wheat, durum flour, farina, gluten, graham, flour, high-gluten flour, high-protein flour, kamut flour, laubina, leche alim, malted cereals, Minchin, multigrain produces, puffed wheat, red wheat flakes, rolled wheat, semolina, shredded wheat soft wheat flour, spelt, superamine, triticale, vital gluten, vitalia macaroni, wheat protein powder, wheat starch, wheat tempeh, white flour, whole-wheat berries. Also beware of gelatinized starch, hydrolyzed vegetable protein, modified food starch, starch vegetable, gum, and vegetable starch. |
Step 3: The Challenging Phase
Reintroducing the Eliminated Foods
Rule of 3s:
- 3 weeks of elimination,
- then challenge during all 3 meals of 1 day,
- then wait 3 days before another rechallenge.
Symptoms will often worsen for a few days before they improve.
Given the subtleties of how food intolerances manifest, eliminating a food is not enough to determine if it might be a problem. Reintroducing the food will provide yet another way to assess an association between foods and symptoms, given the waxing and waning course of most diseases. On the single day of a food or food groups reintroduction, one should eat increasing quantities with each meal. Starting low is important, in case a serious adverse reaction occurs with an exposure to even a small amount of food. Because it can take several days for symptoms to reappear, a 3-day waiting period after reintroduction is recommended. Regardless of what occurs, that food should then be eliminated again. A new food is reintroduced, and the cycle starts again. The section below summarizes the timing for a typical elimination diet process.
Elimination Diet Timing
Begin Elimination Diet
- Week 1: Symptoms may worsen
- Week 2 and 3: Symptoms may improve
- Reintroduction Day (Food #1): Reintroduce one eliminated food, in increasing amounts, at all three meals for just 1 day
- Watching and waiting for 3 days: Symptoms may worsen or not; then continue to eliminate selected food after 1-day reintroduction
- Reintroduction Day (Food #2): Reintroduce a different eliminated food, in increasing amounts, at all three meals for just 1 day
- Watching and waiting for 3 days: Symptoms may worsen or not; then continue to eliminate selected food after 1-day reintroduction
- Reintroduction Day (Food #3): Reintroduce a different eliminated food, in increasing amounts, at all three meals for just 1 day
and the cycle continues until all foods have been evaluated
Step 4: The Maintenance Phase
THE BEGINNING OF A NEW DIET (AND A BETTER LIFE!)
After the elimination diet has been completed, a new diet should emerge that removes specific foods or food groups long term. If it is not found to be beneficial, another elimination diet could be instituted at a later time.
If one is avoiding specific food groups that are associated with higher levels of specific vitamins or nutrients, other foods that are tolerated might need to be eaten in higher amounts to make up for these deficits (e.g. increasing leafy green intake if one is avoiding dairy foods). Dieticians can be valuable team members for assisting with these issues.
Foods that cause an IgE-mediated food allergy should NOT be reintroduced.
Given that the removal of problematic foods or food groups can allow the body to heal, one may be able to reintroduce eliminated foods (using the every-3-days process described above) in 3-12 months. In this way, elimination diets not only may alleviate symptoms but also may treat disease. Ideally, the clinician will work with the patient to improve the ecosystem of the GI tract, reduce intestinal permeability, and enhance tolerance so that formerly problematic foods can eventually be reintroduced.
Author(s)
Elimination Diet was written by David Lessens, MD, MPH (2014). Sections of this Whole Health Tool were adapted from Food Intolerance and Elimination Diet by Adam Rindfleisch (Integrative Medicine, 3rd Edition)
