Why Restrictive Eating Isn’t The Answer To Gut Health

Why do people turn to restriction?

Digestive symptoms can be distressing. They impact energy, mood and confidence, not to mention daily life and any social activities. It makes sense that when people cannot find clear explanations for their symptoms, they resort to self-diagnosis, food intolerance tests and elimination diets.

On the one hand, elimination of certain foods is not entirely unfounded. For many people, a reduction in FODMAPs such as lactose, wheat and certain fruits and vegetables can significantly reduce symptoms^1,2. However, the low FODMAP diet is complex to follow fully without dietitian support and those food intolerance tests are largely inaccurate, which can lead to large amounts of unnecessary restriction^1,2.

The role of the gut microbiome

The gut microbiome plays a critical role in gut function, immune regulation and even mood. One of the most important factors influencing it is dietary diversity, which shows why restrictive diets are not helpful. Studies consistently show that eating a wide range of plant-based foods supports a more diverse and balanced microbiota.

The American Gut Microbiome study in 2018 highlights this, with participants who ate 30 or more different plant foods in a week having a more diverse microbiome than those eating fewer than 10 plant foods^3,4. In contrast, restrictive diets can reduce microbial diversity, weakening the gut barrier and potentially worsening symptoms over time⁵.

Even the low FODMAP diet, which is a clinical diet often used for IBS, is not designed for long-term use. The elimination phase can reduce gut symptoms in the short term, but this also decreases levels of beneficial bacteria, showing why the reintroduction phase is so key^1,5. This is why guidance from a trained dietitian is crucial during any elimination phase.

Cutting out foods: the risks

Restricting multiple foods without proper medical advice can:

• Lead to potential nutrient deficiencies, particularly in fibre, calcium, vitamin A, iodine and B vitamins^6,7
• Increase the risk of disordered eating or food fears
• Heighten sensitivity to previously tolerated foods due to loss of exposure
• Worsen overall gut function due to reduced microbial fuel, i.e. fermentable fibres

What starts as a simple "gut reset" can spiral into an overly rigid way of eating that does more damage than good.

The gut–brain connection: stress matters

The gut is deeply influenced by our emotional state. Anxiety, stress and low mood are strongly associated with digestive symptoms. Research now shows that cognitive behavioural therapy (CBT) and mindfulness are as effective as the low FODMAP diet in improving IBS symptoms without dietary changes⁸. Yoga has also been shown to have benefits due to its impact on the nervous system⁹. This suggests that addressing stress and the nervous system should be a key part of gut health care.

When people feel anxious around food, whether because of symptoms or restrictive rules, the body enters a stress state that can impair digestion, slow motility and increase bloating. It becomes a vicious cycle.

So, what’s a better way forward?

Gut-friendly eating is less about removing foods and more about rebuilding our gut microbes and increasing the diversity of the diet. Research-backed strategies include:

• Increasing dietary diversity – aim for 30+ different plant foods per week
• Eating regular, balanced meals – to support motility and microbial rhythms
• Focusing on fermentable fibres – such as oats, beans, bananas and onions, in tolerable amounts
• Practising mindfulness around eating – reducing mealtime stress and improving digestion
• Targeted reintroduction – if foods have already been restricted, gradual reintroduction is essential to rebuild tolerance

Practical tips for healthcare professionals

Healthcare professionals can play a key role in steering patients away from unhelpful restrictions. Evidence-based approaches include:

• Screen for disordered eating behaviours before recommending any elimination diet.
• Refer to a specialist dietitian for structured guidance through restrictive protocols like the low FODMAP diet ¹.
• Prioritise dietary diversity and prebiotic-rich foods over long-term food avoidance ^4,5.
• Educate patients on the gut–brain axis and recommend psychological support where appropriate ^8,9.
• Encourage realistic, flexible eating patterns to support both microbiome and mental health.

By promoting a balanced, non-restrictive approach, clinicians can help patients find long-term relief while maintaining nutritional adequacy and a positive relationship with food.

Conclusion

Cutting out foods may offer short-term relief, but it is not a sustainable or evidence-based strategy for most gut health concerns. With the right support, patients can nourish their gut, not fear it, using food as part of the solution rather than the problem.

References

1. Cristofori F, Castellaneta S,et al. Unlocking the potential of the low FODMAP diet: comprehensive insights into clinical efficacy, microbiome modulation, and beyond. Expert Rev Gastroenterol Hepatol. 2025 Jul;19(7):767-787. doi: 10.1080/17474124.2025.2519160. Epub 2025 Jun 23. PMID: 40497754.

2. Böhn L, Störsrud S, Törnblom H, et al. Self-reported food-related gastrointestinal symptoms in IBS are common and associated with more severe symptoms and reduced quality of life. Am J Gastroenterol. 2013;108(5):634–641.

3. McDonald D, Hyde E, Debelius JW, et al. American Gut: an open platform for citizen science microbiome research. mSystems. 2018;3(3):e00031-18.

4. Wu GD, Chen J, Hoffmann C, et al. Linking long-term dietary patterns with gut microbial enterotypes. Science. 2011;334(6052):105–108.

5. Staudacher HM, Whelan K. The low FODMAP diet: Recent advances in understanding its mechanisms and efficacy in IBS. Gut. 2017;66(8):1517-1527.

6. Mazzawi T, Hausken T, Gundersen D, et al. Nutritional aspects in irritable bowel syndrome. J Neurogastroenterol Motil. 2016;22(3):449–460.

7. Ostgaard H, Hausken T, Gundersen D, El-Salhy M. Diet and effects of diet management on quality of life and symptoms in patients with irritable bowel syndrome. Mol Med Rep. 2012 Jun;5(6):1382-90. doi: 10.3892/mmr.2012.843. Epub 2012 Mar 22. PMID: 22446969.

8. Hamal A, Shin A, van Tilburg MAL. Yoga, Meditation, Mindfulness, or Hypnotherapy for GI Disorders: Similar Mechanisms of Action? Neurogastroenterol Motil. 2025 May;37(5):e15014. doi: 10.1111/nmo.15014. Epub 2025 Feb 3. PMID: 39901652.

9. Saab O, Al-Obaidi H, et al. Yoga for Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am J Gastroenterol. 2025 May 13. doi: 10.14309/ajg.0000000000003524. Epub ahead of print. PMID: 40358469.