A new study published in September has reinforced how, for people with IBS who have been taught the low FODMAP diet, uncontrolled digestive symptoms and psychological distress can be linked to disordered eating behaviours. It can help us think about how patients are screened for links to eating disorders, and how their relationship to food is monitored throughout any dietary changes and their treatment.
The study by Silva et al.[1] was published in JGH Open on 7 September 2026. It was a cross-sectional assessment of 74 people in Australia with IBS who had previously received low-FODMAP education from a gastrointestinal dietitian. Follow-up occurred a mean of 7.1 years after dietary education, with a range of 2.5 to 13.4 years.
Study findings
The study did not find an association between disordered eating behaviours, the extent to which the patients still followed the FODMAP diet, or how long they had followed the restriction phase of the diet.
There was however a link between IBS symptom severity and psychological distress that were independently strongly associated with ARFID and orthorexia risk.
During the study period 38% (28 out of 74) showed disordered eating behaviours on one of the study’s risk screening tools. For example, 24% scored positively on ARFID screen NIAS (Nine-Item ARFID Screen), 21% on the ORTO-7, a measure of orthorexic eating behaviours and 7% met the EAT-26 threshold for clinically significant eating disorders.
Whilst this is a relatively small cohort of patients there are useful considerations for any health professional working with IBS and other chronic gut health conditions.
Screening before prescribing a restrictive diet
Assessing all IBS patients for a disordered relationship to food before the low FODMAP diet is important. This study did identify six people with a previous eating disorder diagnosis, who’d also been advised to follow the low FODMAP diet.
No new eating disorders were identified and the research didn’t find any evidence of worsening existing eating disorders.
The issue with many screening tools is that they aren’t validated for patients with digestive conditions. In the SCOFF tool (used in screening for eating disorders) one of the questions is ‘would you say that food dominates your life?’. For many people with IBS every meal is a possible flare up trigger and thoughts of how each meal affected digestion is quite normal.
In the NIAS screening for ARFID the questions about ‘I eat small portions because I’m afraid of GI discomfort, choking or vomiting’ and ‘I restrict myself to certain foods because I’m afraid of GI discomfort, choking or vomiting’ seem quite reasonable given some patients’ histories of reacting to foods.
Because these tools aren’t specifically for a population with gut symptoms such as abdominal pain, erratic bowel movements, bloating, or gas it can make using the assessment tools slightly harder. Screening for disordered eating in IBS should take into account their current diet, history with food and feelings about eating.
Additional questions that a health care provider might consider would be:
- How many foods do you currently avoid and what can you eat now?
- Do you skip meals because of anticipated symptoms?
- Do you avoid eating before leaving the house?
- How much time do you spend thinking about whether food will cause symptoms?
- How’s your relationship with food?
- Is the list of safe foods getting smaller?
- Are people around you worried about what you eat?
People with an eating disorder, significant disordered eating, very limited food intake or risk of malnutrition are probably not suitable for any kind of restrictive diet, including the low FODMAP diet. Even though the FODMAP diet is an intervention with a clear process for food reintroduction, there are some people for whom the rules during the restriction can trigger unhelpful eating behaviours and thought patterns.
Uncontrolled symptoms affecting eating behaviours
We should look at the way the uncontrolled digestive symptoms can impact on someone’s life and how that is driving eating patterns and thought processes about food.
This recent study highlights how disordered eating behaviours were associated with greater symptom burden and psychological distress, rather than just how many FODMAPs participants were eating. This could suggest that persistent uncontrolled symptoms are important drivers of disordered eating behaviours rather than solely dietary restrictions, although the cross-sectional design means the study cannot establish cause and effect.
The low FODMAP diet process is intended to move patients towards a more personalised diet, having tested whether each FODMAP group adds to their digestive symptoms. The reintroduction element (Phase 2 of the diet) is important but patients can be very apprehensive about this process.
This study found that those people identified at risk of disordered eating who returned for Phase 3 (diet personalisation) were not able to reintroduce FODMAPs to tolerance. In comparison 54% (7 out of 13) who were not identified as at risk were able to follow the reintroduction process.
Whilst this is a small set of people, it could highlight how important it is to get proper support for the FODMAP reintroduction. Some patients are handed a list of high FODMAP foods to avoid and left to manage the diet themselves. It may also indicate that the reintroduction and personalisation of the diet requires careful support from trained practitioners and people left to do this alone can struggle to overcome the fear around eating.
The gut-brain connection
We know IBS is a disorder of gut-brain interaction involving both gastrointestinal and psychological mechanisms. The two-way communication can affect visceral hypersensitivity, altered motility and central processing of gut sensations alongside psychological factors. In this study 20 participants (27%) took medication for depression or anxiety, and 10 (14%) reported using psychological intervention such as meditation, or gut‐directed hypnotherapy.
Patients may be looking for the next food trigger to remove, but persistent gut symptoms shouldn’t automatically lead to increasingly restrictive eating.
A 2026 network meta-analysis of 68 randomised trials found evidence for several brain-gut behavioural therapies, including CBT, gut-directed hypnotherapy and psychotherapy approaches in IBS.[2] However this study highlighted some publication bias or low certainty of evidence.
Multidisciplinary teams
Where significant anxiety or psychological distress is present dietetic and psychological care should be coordinated rather than treating food and mental health as separate problems.
A multidisciplinary approach to IBS with psychological comorbidity is supported in the literature, with integrated nutrition and brain-gut behavioural approaches. Where an eating disorder or ARFID is suspected, practitioners should refer to specialist eating-disorder services for proper assessment and diagnosis. In the UK, this can mean referral through the patient’s GP/NHS eating-disorder pathway, with specialist services such as Beat available for information and support.
Conclusion: diet restriction in IBS can be a tool, but not the end point
In this cross-sectional study disordered eating behaviours were more associated with IBS symptom severity and psychological distress. The findings do not show that the low FODMAP diet causes eating disorders.
For practitioners, the message is therefore not to avoid all elimination diet interventions altogether, but to consider who is appropriate for restriction, monitor how the intervention is affecting the patient’s relationship with food, and have a clear plan for reintroduction and personalisation. If IBS symptoms remain uncontrolled, the answer is not necessarily to look for another food to remove, but focus on how to manage the digestion more widely.
Author Bio
