What Is an Elimination Diet?

Elimination diets are used to help identify foods that may be related to symptoms such as diarrhea, bloating, gas and other problems. They are meant to be followed for a relatively short period of time, ranging from four to eight weeks.

Different health care providers administer elimination diets, including gastroenterologists, allergists and registered dietitian nutritionists (RDNs). Depending on the symptoms, a health care provider will typically rule out other conditions before an elimination diet is used. For example:

• If celiac disease is suspected, the physician might perform a biopsy to test tissues in your intestine for signs of this condition.
• Or, a breath test might be done to rule out lactose or fructose intolerance. Breath tests measure the amounts of certain gases in the breath after eating particular foods, like those with lactose. These gases occur when your body does not digest certain compounds.

Elimination diets require motivation. It can be tough to make the needed dietary changes even though it is only on a short-term basis. Also, if you’re taking any medicines, discuss them with your physician before making changes to your diet and consult with an RDN. Dietitians have the ability to analyze your diet and identify any nutrients that may be lacking and make recommendations for healthy substitutions based on your individual preferences. They also can offer tips on meal planning and reading food labels.

How Elimination Diets Work

Most elimination diets have two phases:

• Elimination phase
• Reintroduction phase

Elimination Phase

During the elimination phase, you stop eating all foods that are thought to be bothersome. The goal is to see if by restricting these foods your symptoms go away. Often people are aware of which foods appear to cause their symptoms. However, a health care provider can help you to determine which foods might be troublesome for you.

You might be instructed to eliminate one food at a time, groups of similar foods such as a food group, or multiple food items. For example, if lactose intolerance is suspected, a health care provider might recommend you avoid all dairy foods, including milk, yogurt and cheese. If gluten intolerance is suspected, you will be given a list of foods to restrict that contain gluten. These may include wheat, rye, barley and processed foods that may contain gluten such as malt vinegar, pre-seasoned meat and some lunch meats.

Working with an RDN can be helpful during this phase. The RDN can review your typical eating habits and give you a list of food items to eat in place of the foods you need to eliminate. In addition, the RDN can help to design an elimination diet that considers your individual food preferences.

Reintroduction Phase

If your symptoms have improved, the next step is to reintroduce the foods that were restricted. The goal is to see if by eating these foods your symptoms return. During this phase, a person tracks which foods are tolerated. Usually, starting with a small amount, one food item at a time is added back into your eating plan. If the symptoms do not return, a larger portion of the food is tested for tolerance. The person records the amount of the food tolerated. The reintroduction phase continues until all the potentially bothersome foods are tested.

Sometimes, food intolerances may relate to an ingredient used in a specific product or food brand. This is common with sulfite sensitivities. Some dried foods, for example, contain sulfites. But while one brand of dried fruit may contain sulfites, another may not, so label reading and detailed food records can be very helpful.

Three Things to Remember about Elimination Diets

1. Elimination diets are not meant to be followed for long periods of time and should only be done under the supervision of a health care provider.
2. An RDN can help you follow an elimination diet that also meets your nutrition needs.
3. The outcome of an elimination diet is an individualized eating plan, which may include a list of foods to restrict, eat occasionally or consume in smaller amounts.

Finding an RDN

Ask your health care provider for a referral to a dietitian. Or, search the Academy of Nutrition and Dietetics' Find a Nutrition Expert database to locate an RDN in your area.