What is an elimination diet?
An elimination diet – also known as an exclusion diet – involves removing foods and drinks from your diet that may be causing you symptoms that aren't resolved with other treatments.
A simple elimination or exclusion diet will cut out just one food or food type from your diet to see if symptoms improve. A more complex exclusion diet may require you to remove a large number of foods, which if followed long-term may increase your risk of nutrient deficiencies. The more complex elimination diets need dietitian involvement, as nutrient deficiencies may cause the symptoms you are trying to manage.
The initial diet restrictions are usually managed for between 2 to 6 weeks. You then slowly reintroduce foods, often in a planned order of reintroduction, paying attention to the effect on your body and monitoring any symptoms or reactions. An elimination diet can help identify a dietary trigger of digestive problems like diarrhoea, when other causes have been ruled out by your GP.
Seek medical help
Before you start changing what you eat, it's very important to seek medical advice to rule out other possible health reasons for your symptoms. If it's established that an elimination diet may help, your doctor may refer you to an appropriate specialist. A dietitian can work with you to tailor the diet to your personal needs. Don't go it alone. It's important for your overall health to ensure you maintain a healthy, balanced diet and get enough essential nutrients from the key food groups.
How does the diet work?
Trial elimination and challenge diets involve removing any food suspected of causing a reaction and adding it back later to see if your symptoms return. The process is considered the 'gold standard' for diagnosing food sensitivity and intolerance. It is important to 're-challenge' yourself with any food identified that may have caused your symptoms, to confirm the food is responsible.
Tests arranged by your GP or hospital team may help guide dietary exclusions. However, skin and blood tests arranged elsewhere are unreliable and are not recommended to diagnose food intolerance. NICE guidelines recommend against IgG testing, Vega testing, applied kinesiology and hair analysis stating these are unreliable ways to diagnose food intolerance.
If you have eliminated the suspected food, or foods, for the recommended time but there's no change to your condition, the cause is probably not your diet. If your symptoms go away when you remove the food, and return when you reintroduce it, you have probably identified the culprit.