Food allergies and intolerances are common among children and adults.
While identifying the food or foods causing the food allergy or intolerance can be difficult, following an elimination diet can help.
This article explains everything you need to know about the elimination diet including what it is and how it works.
What is the elimination diet?
The elimination diet involves removing foods or ingredients from your diet that you believe are causing allergy or intolerance symptoms.
The eliminated foods are later reintroduced, one at a time, while you identify which foods are contributing to your symptoms.
You can then eliminate the food from your diet to prevent any uncomfortable symptoms in the future.
A food allergy is not the same as food intolerance or sensitivity, although they may share similar symptoms.
Symptoms of an allergy include tingling or itching in the mouth, itchy skin, wheezing or shortness of breath, or swelling of the face, mouth, tongue, or other parts of your body.
In contrast, food intolerance symptoms are generally less serious and often limited to digestion problems such as diarrhea, bloating, gas, constipation, and nausea.
If you have a known or suspected food allergy, then you should only follow the elimination diet under the supervision of your health care provider since reintroducing a food allergen can be dangerous.
Beyond food allergies and intolerances, the elimination diet may also be helpful if you frequently experience headaches or if you have an inflammatory condition like eczema, acne, psoriasis, irritable bowel syndrome (IBS), or eosinophilic esophagitis (1, 2, 3, 4).
People with congenital sucrase-isomaltase deficiency (CSID) can also benefit from an elimination diet.
How to do the elimination diet
An elimination diet consists of two phases — elimination and reintroduction.
The elimination phase
The elimination phase involves eliminating foods that you suspect are causing your symptoms.
Eliminate the suspected foods and foods commonly associated with intolerance symptoms for a short period of time, usually 2–6 weeks (5).
These foods may include dairy products, wheat, fermented foods, deli meats, dried or preserved seafood, and certain vegetables like avocado, spinach, tomatoes, and apples (5).
During this phase, you can determine whether your symptoms resolve or if your symptoms are due to something else.
The reintroduction phase
In the reintroduction phase, you slowly bring the foods you eliminated back into your diet.
Reintroduce each food, one at a time, slowly over three days while you look for symptoms.
Some foods such as those that contain salicylates require a longer reintroduction phase of up to 10 days due to the gradual build-up over several days that may be needed to cause a reaction (5).
Symptoms to look for include:
- a change in bowel habits
- stomach pain
- difficulty sleeping
- joint pain
- rashes or skin changes
If you experience no symptoms after reintroducing a food, you can assume that food is not the culprit and then reintroduce the next food.
Conversely, if you do experience symptoms, you should remove that food from your diet.
However, complete elimination isn’t always necessary with a food intolerance. For example, people with lactose intolerance can tolerate up to 12 grams of lactose — equivalent to 1 cup (240 mL) of milk — without problems (6).
The elimination diet process, including the elimination phase, takes 6–10 weeks, depending on how many foods you eliminate and reintroduce.
It’s best to keep a journal so you can document which foods you eliminated and what symptoms you experience — if any — after reintroducing them into your diet.
Elimination diet food list
Elimination diets may restrict several foods or just one.
Foods to avoid
The more foods you remove during the elimination phase, the more likely you will identify which foods trigger your symptoms.
Foods that are often eliminated include (6):
- Fruits: certain fruits including apples, bananas, tomatoes, pears, and avocado
- Vegetables: eggplant, spinach, onions, and garlic
- Grains: wheat, rye, barley, and corn
- Tree nuts: almonds, cashews, pistachios, and walnuts
- Legumes: peanuts, peas, and beans, including soybeans
- Meats: deli meats, ham, and
- Dairy products: milk, cheese, yogurt, and ice cream
- Seafood: fish and shellfish such as lobsters, mussels, and crab
- Fermented foods: saurkraut, kombucha, and kimchi
- Sweets: honey, chocolate, and other types of candy
- Beverages: alcohol and caffeine-containing drinks like coffee, tea, soda, and energy drinks
This list is not all-inclusive, so there may be foods beyond this list that provoke your symptoms.
Foods to eat
An elimination diet can be extremely restrictive, which limits the foods you can eat.
Some foods you can eat include:
- Fruits: most fruits, excluding those listed on the elimination list
- Vegetables: most vegetables, excluding those listed on the elimination list
- Grains: oats, rice, quinoa, and millet
- Meat and poultry: fresh beef, lamb, chicken, and turkey
- Milk alternatives: coconut milk, rice milk, and almond milk
Risks of an elimination diet
Despite the popularity of at-home food sensitivity tests, there remains a lack of evidence to support these tests for accurately identifying food sensitivities (7).
Consequently, the inaccuracy of these tests could cause you to unnecessarily avoid healthy foods.
As such, the elimination diet is a better place to start.
However, you should only follow an elimination diet for a short period of time — no longer than 10 weeks — as it could lead to nutrient shortfalls as a result of limiting entire food groups (8).
The diet can also severely restrict the number of calories you consume, which could lead to unintended weight loss.
Therefore, you should always check with your doctor or work with a registered dietitian for guidance on following an elimination diet.
The bottom line
Following an elimination diet can help you identify which foods your body can’t tolerate well.
The diet consists of a restriction and reintroduction phase, and the entire process can take 6—10 weeks, depending on the number of foods you eliminate.
The elimination diet can be restrictive, so it’s best to work with your doctor and dietitian, especially if you have a known or suspected food allergy.