Are you among the 15 to 20% of individuals who struggle with food intolerances? (13)(15) A food intolerance, also known as food sensitivity, may be associated with a variety of symptoms, including abdominal pain, bloating, fatigue, headaches, and rashes. (2)
With a broad range of symptoms and possible mechanisms, understanding and diagnosing an individual food intolerance can be challenging. The elimination diet is a commonly used method to identify the foods that may be causing sensitivity reactions. (13) Read on to learn about food sensitivities, the role of the elimination diet, and some simple guidelines for how to do an elimination diet.
What is a food intolerance?
A food intolerance or sensitivity is the most common type of adverse response to food. It can involve an immunological and non-allergic response to food at a normally-tolerated dose. (13) Food intolerance may occur as a result of intestinal permeability, (14) enzyme defects, or the pharmacological effects of food or components of food. (5) For example, some symptoms such as hives may be related to histamine intolerance, a compound naturally present in certain foods. (3) High dietary histamine intake and/or reduced activity of enzymes responsible for breaking down the compound can result in excess histamine and associated food intolerance symptoms. (13)
A food sensitivity can result in gastrointestinal symptoms such as bloating and abdominal pain. (2)
It’s important to note that food sensitivity differs from food allergy. Food allergies are an abnormal immune response to food which affects less than 10% of children and approximately one to two percent of adults. (5)(13) An allergic response is considered immediate, as the symptoms are present within several minutes to hours after consuming the food. (6)
Food intolerance symptoms
Food intolerance symptoms vary and include gastrointestinal and extra-intestinal symptoms, such as:
- Abdominal pain
- Altered bowel habits (e.g., diarrhea or constipation)
- Bloating
- Brain fog or “foggy mind”
- Fatigue
- Flatulence
- Headache
- Insomnia/disturbed sleep
- Musculoskeletal symptoms (e.g., joint/muscle pain, numbness)
- Nausea
- Skin rash/dermatitis (2)
A food sensitivity may also contribute to certain health conditions, including gastroesophageal reflux disease (GERD), (1) eosinophilic esophagitis (EoE), (4) and irritable bowel syndrome (IBS). (12)(13)
What is the elimination diet?
The elimination diet is a three-step dietary program used to identify food sensitivities associated with certain symptoms. The first step involves eliminating commonly reactive foods from the diet for a period of two to six weeks. During the second step, foods are reintroduced one by one while monitoring for food intolerance symptoms. The third step involves maintenance of an individualized diet that excludes any food intolerances uncovered during reintroduction. (6)(7)(13)
The most well-known type of elimination diet involves the exclusion of multiple foods, which eliminates the most common foods that cause irritation. For example, the six-food elimination diet excludes casein (dairy protein), soy, wheat, eggs, peanuts/tree nuts, and seafood. (4)(10)
There are a number of other variations of the elimination diet, such as:
- Single-food exclusion, which eliminates one suspected food (e.g., eggs or dairy) (4)(10)
- The ‘few-food’ diet, also referred to as an oligoantigenic diet, which consists of consuming only certain foods with a low reaction potential, such as quinoa, rice, lamb, venison, and pears (7)
- The low-FODMAP diet plan (Fermentable Oligo-, Di- and Monosaccharides, and Polyols), which eliminates foods containing short-chain carbohydrates, such as wheat, rye, garlic, legumes, and dairy, as well as sugar alcohols found in foods such as apples, stone fruit, mushrooms, and cauliflower (7)
The elimination diet temporarily excludes common reactive foods such as wheat, dairy, and eggs.
How to do an elimination diet
The key to a successful elimination diet is education, planning, and self-awareness to recognize changes in symptoms. The following rules are helpful guidelines to consider when following the elimination diet.
Learn the facts about the elimination diet.
Rule 1: Choose the right time
Before beginning an elimination diet, ensure that you will be able to dedicate the time it takes to complete the elimination and reintroduction phases. Holidays, trips, and major life events may interfere with your ability to follow the diet successfully. Keep in mind that it’s important to strictly adhere to the diet in order to properly identify a food sensitivity, otherwise, it may be difficult to identify the specific cause of a reaction.
Rule 2: Eliminate triggers
Potential food sensitivities should be entirely eliminated from the diet for a period of two to six weeks. There may be a decrease in symptoms during this elimination phase. (6)(13) Selecting which foods to remove can depend on several factors including typical diet, suspected food intolerance, and symptomatic profile. (13)
The most common foods to exclude on an elimination diet include:
- Chocolate
- Citrus fruits
- Dairy
- Eggs (7)
- Nightshade vegetables (e.g., tomato, potato, eggplant, peppers) (11)
- Nuts (7)
- Soy (10)
- Wheat and gluten (7)
Rule 3: Follow a reintroduction schedule
After eliminating the above foods for two to six weeks, each food should be reintroduced one at a time. (7) As food sensitivity reactions are not immediate and could appear up to 14 days after ingestion of the trigger food, (6) most elimination diet meal plans suggest reintroducing food several days apart in order to distinguish symptoms related to individual foods. (3)(6) Keep in mind, the overall duration of the diet will be determined by the number of foods eliminated and reintroduced.
Rule 4: Planning is key
Meal planning and preparation will ensure that you always have food available that complies with the elimination diet. Strategies to save time and make the most of your meals include cooking extra servings and reusing leftovers. Meals such as soups, stews, and casseroles can be made in batches ahead of time and frozen or refrigerated for quick, convenient dishes.
Rule 5: Make your own meals
Cooking your own meals is the best way to ensure the ingredients used comply with your elimination diet meal plan. Eating out at restaurants or purchasing prepared foods from the store may unknowingly expose you to foods that may interfere with your reintroduction schedule.
Preparing your own food at home can help you stay on track with the elimination diet.
Rule 6: Choose quality foods
Packaged and refined foods often contain food additives, such as colors, preservatives, or commonly irritating ingredients listed under different names, which may be related to your food intolerance symptoms. (3)(9) Choosing organic foods can minimize your exposure to additives, herbicides, and pesticides and associated adverse effects. (8)
Read more about environmental toxins and health on the Fullscript blog.
Rule 7: Keep a diet diary
Keeping a diet and symptom diary while on the elimination diet can be an effective tool to help identify which foods are triggering symptoms. (3) This involves keeping track of foods consumed for meals and snacks, as well as any health symptoms experienced.
Rule 8: Read your supplement labels
In addition to food sources, potential food sensitivity triggers may also be present in dietary supplements. Be sure to read the label and look for third-party certifications. Third-party certifications, such as gluten-free certifications, can help you identify common reactive ingredients excluded from the product.
For example, common additional ingredients that may contain or be derived from gluten-containing grains include:
- Caramel coloring
- Dextrans
- Dextrose
- Maltodextrin
- Pregelatinized starch
- Starch (7)
The bottom line
As food intolerances can be difficult to identify, the elimination diet can be used as an effective method to determine food triggers of symptoms. (13) Following an elimination diet is generally considered to be safe, (7) however, individuals may experience the return of food intolerance-related symptoms during the reintroduction phase.
While nutrient deficiencies are uncommon with a well-planned diet, the long-term exclusion of certain foods without the replacement of missing nutrients may result in deficiencies over time. For example, long-term dairy exclusion may increase the risk of calcium and vitamin D deficiency. (6) Before beginning an elimination diet meal plan, consult an integrative healthcare practitioner who can ensure that the diet is individualized and the risk of nutrient deficiencies and adverse events are minimized. (7)(13)
- Caselli, M., Lo Cascio, N., Rabitti, S., Eusebi, L. H., Zeni, E., Soavi, C., … Zagari, R. M. (2017). Pattern of food intolerance in patients with gastro-esophageal reflux symptoms. Minerva Medica, 108(6):496-501.
- Catassi, C., Elli, L., Bonaz, B., Bouma, G., Carroccio, A., Castillejo, G., . . . Fasano, A. (2015). Diagnosis of non-celiac gluten sensitivity (NCGS): The Salerno experts’ criteria. Nutrients, 7(6), 4966-4977.
- Guida, B., Martino, C. D., Martino, S. D., Tritto, G., Patella, V., Trio, R., . . . D’Agostino, L. (2000). Histamine plasma levels and elimination diet in chronic idiopathic urticaria. European Journal of Clinical Nutrition, 54(2), 155-158.
- Kagalwalla, A. F., Shah, A., Li, B. U., Sentongo, T. A., Ritz, S., Manuel-Rubio, M., … Nelson, S. P. (2011). Identification of specific foods responsible for inflammation in children with eosinophilic esophagitis successfully treated with empiric elimination diet. Journal of Pediatric Gastroenterology and Nutrition, 53(2):145-9.
- Lomer, M. C. (2014). Review article: The aetiology, diagnosis, mechanisms and clinical evidence for food intolerance. Alimentary Pharmacology & Therapeutics, 41(3), 262-275.
- Ly, V., Bottelier, M., Hoekstra, P. J., Arias Vasquez, A., Buitelaar, J. K., & Rommelse, N. N. (2017). Elimination diets’ efficacy and mechanisms in attention deficit hyperactivity disorder and autism spectrum disorder. European Child & Adolescent Psychiatry, 26(9), 1067-1079.
- Madzhidova, S., & Sedrakyan, L. (2019). The use of dietary interventions in pediatric patients. Pharmacy (Basel, Switzerland), 7(1), 10.
- Mie, A., Andersen, H. R., Gunnarsson, S., Kahl, J., Kesse-Guyot, E., Rembiałkowska, E., … Grandjean, P. (2017). Human health implications of organic food and organic agriculture: a comprehensive review. Environmental Health, 16(1), 111.
- Nigg, J. T., Lewis, K., Edinger, T., & Falk, M. (2012). Meta-analysis of attention-deficit/hyperactivity disorder or attention-deficit/hyperactivity disorder symptoms, restriction diet, and synthetic food color additives. Journal of the American Academy of Child and Adolescent Psychiatry, 51(1), 86–97.e8.
- Nigg, J. T., & Holton, K. (2014). Restriction and elimination diets in ADHD treatment. Child and Adolescent Psychiatric Clinics of North America, 23(4), 937–953.
- Nosrati, A., Afifi, L., Danesh, M. J., Lee, K., Yan, D., Beroukhim, K., … Liao, W. (2017). Dietary modifications in atopic dermatitis: patient-reported outcomes. The Journal of Dermatological Treatment, 28(6), 523–538.
- Soares, R. L. (2018). Irritable bowel syndrome, food intolerance and non-celiac gluten sensitivity. A new clinical challenge. Arquivos De Gastroenterologia, 55(4), 417-422.
- Tuck, C. J., Biesiekierski, J. R., Schmid-Grendelmeier, P., & Pohl, D. (2019). Food Intolerances. Nutrients, 11(7), 1684.
- Ventura, M., Polimeno, L., Amoruso, A., Gatti, F., Annoscia, E., Marinaro, M., . . . Francavilla, A. (2006). Intestinal permeability in patients with adverse reactions to food. Digestive and Liver Disease, 38(10), 732-736.
- Zopf, Y., Baenkler, H. W., Silbermann, A., Hahn, E. G., & Raithel, M. (2009). The differential diagnosis of food intolerance. Deutsches Arzteblatt international, 106(21), 359–370.