This article was written by The Mission Dietitian intern, Klaudia Sokolowska.

The number of people reporting uncomfortable gut symptoms has been on the increase in the past few years, and many of those believe that their symptoms are related to diet. Presumably, for this reason, elimination diets have become more common, too. But what are they and could they be a solution for you too?

What are elimination diets and why would someone do it?

The goal of an elimination diet is to pinpoint the culprit of uncomfortable gut symptoms for people with suspected food intolerances. Symptoms can include bloating, tummy pain, wind and/or diarrhoea, and usually happen a few hours after eating. If you believe that your symptoms may be linked to the food you are eating, a good place to start is keeping a food and symptoms diary. Simply note down what foods you eat in a day, what symptoms you experience and when do these happen. After doing so, if you notice consistent patterns, an elimination diet may be an option for you. 

The first step of an elimination diet would be excluding the food you think may be causing you symptoms, importantly one at a time, for about 2 to 6 weeks, and monitoring whether your symptoms improve. If you notice no improvement at all, re-introduce the food back into your diet. If you do notice significant improvement, you may also try to re-introduce small amounts of the food to test your individual tolerance, which can vary greatly from person to person. 

What does the evidence say?

The scientific evidence in the field of elimination diets is very scarce, mainly because it is difficult to define what an elimination diet is! The foods one eliminates are very specific to their symptoms and hence difficult to compare to a large enough group of other people. However, there is promising evidence supporting structured elimination diets for certain medical conditions, such as migraines, ADHD, skin concerns or IBS.

Things to be mindful of if you are considering an elimination diet

Before attempting an elimination diet, there are a couple of points that need to be addressed:

1. Not all symptoms are food related

   The gut is a complex system, affected by a large number of stimuli - from physical activity, to sleep patterns and stress levels. Hence, getting those in check may often be a more viable first-line strategy. 

2. Do not underestimate the impact of first-line dietary changes 

   • Before eliminating any food from your diet, make sure you are covering the basics for a sensitive gut, i.e.

   • getting enough fluids (2L per day) 

   • limiting caffeinated drinks to maximum 3 a day

   • being mindful around alcohol and fizzy drinks

   • limiting fatty and spicy foods

   • avoiding chewing gums and artificial sweeteners

   • not delaying or skipping meals

   • taking your time at mealtimes.

3. Rule out other medical causes for your symptoms

   Food intolerance may present in a similar way to more sinister causes such as coeliac disease or Inflammatory Bowel Disorder (IBD). Before diagnosing yourself with a food intolerance, seek medical help to exclude the above via appropriate testing. Please bear in mind that there are no validated intolerance tests, other than for lactose or fructose breath test, despite being widely advertised by several companies.

   The Low FODMAP diet is also a more complex form of a medical elimination diet, designed specifically for those diagnosed with Irritable Bowel Syndrome (IBS). Its first phase includes cutting out foods high in fermentable oligosaccharides, disaccharides, monosaccharides and polyols, which are short-chain carbohydrates that are poorly absorbed in the small intestine. While is has been shown effective in reducing gastrointestinal symptoms in up to 75% of those diagnosed with IBS, it should never be attempted independently without supervision from a specialist dietitian, nor should it be attempted without a medical IBS diagnosis. 

4. Consider nutritional adequacy of your diet

   Without good preparation, it may be difficult to get all the nutrients that you need during an elimination diet. Especially if you are cutting out large food groups such as dairy (think calcium, iodine) or wheat-containing products (think iron, fibre, B vitamins). Additionally, limiting the diversity of your diet may have a negative impact on your gut microflora - which thrives in a diverse food environment. If possible, you may want to seek professional support from a dietitian to guide you through this process. 

The takeaway message

Elimination diets may be a useful tool if you struggle with gut symptoms that you believe are diet-related. However, before attempting to cut out food from your diet:

• make sure you carefully consider what may be causing your symptoms through a food and symptoms diary, 

• think of non-food related factors and first-line strategies you could implement first, 

• rule out any medical conditions causing your symptoms,

• and make sure you are well prepared to perform the elimination stage, ideally with professional support.

For more support with elimination diets, the low FODMAP diet, and managing your gut symptoms, book in to see a dietitian at the KC Nutrition Clinic.