I frequently hear from many of my clients that “I tried the elimination diet and it didn’t help me at all…” or “I’m still confused about what foods might be bothering me even after 3 months on the elimination diet.”  And while there are some situations where identifying food reactions may not be part of the solution, I frequently find that the elimination diet, when done correctly can reveal a lot of useful information. 

Upon deeper questioning, I usually learn that the trial with the elimination diet was not as helpful as it could have been because the client wasn’t fully informed about the correct way to do the elimination diet, did not have clear directions about all the different steps involved and/or the elimination diet was not the right tool for the job.  Doing the elimination diet correctly is not rocket science but the process does rely on a series of steps to get the full benefit of your experience. 

In this blog post I discuss the most common mistakes and omissions that many people make when doing an elimination diet and how you can avoid them. 

The first error is that of only eliminating one food at a time.   Unfortunately, with some types of food reactions, there can be difficulty with several different foods simultaneously.  In fact, it is quite rare that there is sensitivity to only one food.  This requires that as many as the potential offending foods need to be eliminated at the same time.  It will be very difficult to identify whether gluten, for example, is problematic for you if you’re also having symptoms related to dairy products which hasn’t been eliminated. 

The second problem is that the elimination diet is not done long enough.  A three week period of uninterrupted elimination is the least amount of time required.  Because it takes 21-22 days for the immune system to become less reactive in response to the elimination of certain foods, trying to evaluate how you feel before that 3 week window has passed can be frustrating.  Typically, many clients find that the day 3-5 day can be challenging as they begin to experience the withdrawal of certain foods from their daily diet.  By the time they approach the end of the second week, many clients start to appreciate a shift in their energy level, better sleep, mental clarity, less pain and better overall function.  Conversely, the elimination diet is a diagnostic tool not a permanent lifestyle choice.  It is not meant to be a long-term eating plan.  Nutritional insufficiencies and unhealthy metabolic consequences could arise if used that way.  I always remind clients that the elimination diet is a time-tested, “gold standard” test designed to identify potential food sensitivities.  Once those foods have been identified, it’s time to move on to the next step.  Learn more about the 3 phases of the elimination diet here. 

This next step is called the provocation phase and it frequently is an area of confusion for many doing the elimination diet.  The provocation phase is the thoughtful and purposeful re-introduction of the previously eliminated foods one by one, over time, to determine which ones are the problem foods.  It’s the opposite of the elimination phase where you want to eliminate all potential problem foods at once.  In the provocation phase its critical that you reintroduce only one food at a time. This is where I see the most mis-steps in the process.  Frequently, many clients skip this step or don’t really engage in a purposeful re-introduction.  As a result you can miss out on reaping the benefits of the previous 3 weeks of elimination.   For many, they casually will add back in a little bit of dairy or a couple of eggs here and there over several days and before too much time has gone by, they’re feeling poorly again, convinced that they did not benefit from eliminating any of the suspect foods.  If you notice improvements in any of your symptoms by the end of the first 3 weeks of the elimination phase, then you definitely have a food reaction of some type.  Now, the next mission is to figure out which food or foods are responsible.  That requires at least a 3 day window for each food being re-introduced.  Remember, that some food reactions such as food sensitivities are delayed hypersensitivities.  In this case, your immune system can react to a food up to 72 hours after eating it.  You must give yourself that 3 day window minimum to determine your body’s response.  And you must eat a lot of that food on day 1 of that 3 day window to potentially provoke a reaction.  Remember, the immune system has had 3 weeks to quiet down and become non-reactive.  A small serving may not be enough to cause the immune system to react and present with symptoms that you can then identify as a food reaction.  It’s the equivalent of a false negative which results in you then putting that food back in your daily food plan with unfortunate and confusing consequences.    

The elimination diet should really be renamed the elimination/provocation diet to emphasize that the  elimination of foods is just one part of the equation.  And if we’re being really honest, it actually is more like a 6-8 week commitment because it can take that long to actually get through the re-introduction of all the foods while staying on the elimination diet the whole time.  Putting a food back into your daily consumption, even if it seems like a non-reactive food, before all the foods have been re-introduced is another mistake to avoid.  Sometimes, the more subtle symptoms are missed or we misinterpret our symptoms for something else.  For whatever reason, we just don’t equate how we’re feeling with a possible food reaction so we start eating that food again and it makes it much more difficult to identify  other food reactions. 

Another mistake I see happening is that different foods are re-introduced at the same time.  For example, instead of re-introducing just gluten-containing foods, like wheat cereal or bulgur, someone might have pizza.  In this case, you’ve re-introduced not only gluten-containing food but also dairy.  The re-introduction phase needs to be as simple and clean as possible so you can garner as many of the clues as possible. 

Finally, track your experience and results.  This is beneficial for a number of reasons – it helps to keep us engaged in the process and paying attention as well as provides us with a reference.  When done correctly, the elimination/provocation diet can take up to 8 weeks from start to finish.  Trying to remember how bad your headaches were 3 weeks ago compared to 5 weeks ago can be challenging.  It can be helpful to keep a journal of some sort paying attention to documenting  symptoms, events and foods eaten or re-introduced.  I find that doing this at the very beginning and at the end of the 3 week  elimination phase and again with each new food re-introduced can be very helpful to see emerging patterns.  

So, let's recap.

To get the most out of your elimination/provocation testing avoid these common mistakes: 

  • Eliminate all the suspect foods at once  

  • Plan on doing the elimination phase for a minimum of a 3 week period before re-introducing 

  • Do a thoughtful and focused re-introduction  

  • Eat enough of the food on day 1 of the 3-day re-intro window  to provoke a reaction 

  • If you experience a food reaction, wait until those symptoms resolve before re-introducing another food 

  • Even if you don’t have a reaction to a food, continue to eliminate it until the re-intro phase is complete 

  • Re-introduce just one food at a time and avoid re-introducing another food until any possible symptoms of reaction have resolved completely 

  • Track your experience