Why restrictive diets could be bad for gut health.

A lot of us are led to believe that cutting out certain foods is good for your gut health. You may have tried a low FODMAP diet, cutting out gluten or dairy to alleviate symptoms of digestive issues. Whilst eliminating certain foods may alleviate symptoms in the short-run, in the long-run restrictive diets could actually do more harm than good.

Here’s why…

Out gut is made up of trillions of micro-organisms (between 40-100 trillion) known as our gut microbiome. The diversity of this gut microbiome helps protect us from dysbiosis-related issues and encourages a healthy gut . The diversity and homeostasis of these micro-organisms is largely influenced by what we ingest (food, drink, medicines, recreational drugs, etc.) with environment and stress playing key roles as well. Studies show that eating a restrictive diet (like a low FODMAP diet) long-term can cause negative changes to your gut flora / microbiome₁. Typically restrictive diets eliminate foods that are actually good for you and would help promote growth of healthy gut bacteria.  

Gluten & Dairy

The two most common foods people choose to eliminate when the have gut issues is gluten & dairy. However, both gluten and dairy both have positive impacts on your health.

For those who are diagnosed with celiac disease, gluten sensitivities, or an auto-immune disease, eliminating gluten can be beneficial for their health and gut balance. However, most people who avoid gluten do not have celiac disease or a proved intolerance. In actual fact, studies show there is an increased risk of heart disease in gluten avoiders, potentially because of the reduced consumption of whole grains which are so important for heart health₂.

When you eat cheese (with a focus on whole dairy, not processed cheese, low fat or non-fat) it increases the bifidobacteria in your gut. This can help protect against pathogens and increase the production of short chain fatty acids. Dairy (cheese, milk, yogurt) can be a part of a healthly diet.

If you haven’t had certain foods (such as gluten and diary) in a long time, you need to be careful when re-introducing them. It can cause digestive upset, which may make you believe you are intolerant to them. In actual fact, it is likely you don’t have the bacteria and enzymes to digest the food since it has been removed from your diet. Your body needs time to replenish bacteria to digest food properly. So reintroduce the food slowly, step-by-step.

Other side-effects of restrictive diets

  • When you eliminate foods (and sometimes whole food groups), you aren’t getting the necessary nutrients to help your body heal. 
  • Restrictive diets can set you up for a disordered relationship with food, and sometimes a eating disorder.  You’re more likely to worry about and obsess over food rather than just enjoying it.
  • Restrictive diets don’t address the other important aspects of our health, like stress, sleep, and exercise. These are also important aspects for your gut health – stress especially.

So here are my thoughts. If you choose to do a restrictive diet in an attempt to alleviate gut issues, only do so in the short-run. Perhaps for 2 weeks, or 30 days tops. Don’t make a restrictive diet your new way of eating.

What happens is that when the restrictive diet does alleviate symptoms, you are scared to reintroduce foods that you think caused the initial symptoms. What is important is a slow and thoughtful reintroduction of foods into your diet to replenish your gut bacteria. You can then have better digestion with all foods in your diet and benefit from the health effects of all foods.

If you are currently on a restrictive diet and would love to start incorporating more foods to feel your best, you can schedule a free consultation with me to talk about my health transformation programs.

Love, Emma x


  1. Hill, Muir & Gibson, 2017, Controversies and Recent Developments of the Low-FODMAP Diet, Online, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390324/
  2. BMJ , 2017, 357:j1892, Online, https://www.bmj.com/content/357/bmj.j1892

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