Expert Q&A: Low-FODMAP Diet Risky in Patients With Eating Disorders

In individuals with IBS, screening for an eating disorder or maladaptive eating is recommended prior to recommending the low-FODMAP diet.

Irritable bowel syndrome (IBS) affects an  7% to 21% of the global population and 12% of people in the United States.1 The condition is up to 2 times more common in women than in men and is more likely to occur in people under the age of 50 years.2 Factors that can increase the chance of having IBS includes having a family member with IBS, having a severe infection in your digestive tract, and having a history of stressful or difficult life events.2 IBS is associated with substantial morbidity and disability, underscoring the need for timely diagnosis and treatment.

“Because IBS is a symptom-based disorder, treatments can address abdominal symptoms such as pain, cramping, bloating, or bowel symptoms, including diarrhea and constipation,” wrote the authors of a 2015 review published in JAMA.1 Although over-the-counter laxatives and antidiarrheals are affordable, widely available, and often effective for their intended purpose, these medications may not alleviate pain, bloating, and other symptoms.

In recent years, there has been a growing emphasis on lifestyle and dietary interventions as first-line treatment strategies, including the low-FODMAP (fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols) diet.3 “Foods in these categories are short-chain carbohydrates that can ferment in the intestines if poorly digested, resulting in bloating, abdominal distention, severe pain, gas, and other symptoms,” Stephanie Cohen, RDN, LD, a dietitian in private practice in  Atlanta, Georgia, told Gastroenterology Advisor.

In a 2018 survey of 1562 US gastroenterologists, more than half of providers recommended dietary interventions, especially the low-FODMAP diet (LFD), to >75% of their patients with IBS .4 More than 90% of physicians viewed such strategies as equally or more effective than pharmacologic treatment options for IBS, and 85% perceived the LFD as either somewhat or very effective (65% and 20%, respectively) in IBS management.

Although the LFD has been shown to improve symptoms and quality of life for many people with IBS , it may be inappropriate for those at risk for eating disorders because of  the possibility of triggering or exacerbating such behaviors.3 “Informed gastroenterologists are cognizant of the emerging research on the comorbidity of functional gut disorders and eating disorders. It is essential to screen individuals for eating disorder risk before prescribing an elimination diet,” Kate Scarlata, MPH, RDN, LDN, a Boston-based private practice registered dietitian, and colleagues wrote in a paper published online in August 2019 in Clinical Gastroenterology and Hepatology.3

A 2018 study found that 23% of people with IBS  were at risk for eating disorder behaviors, and this group of patients demonstrated greater adherence to the FODMAP diet compared with those who did not have an eating disorder  (57% vs 35%; P <.05).5 These observations highlight the complex relationship between eating disorders and IBS. However, survey results indicate that only 21% of gastroenterologists regularly refer patients with IBS to registered dietitians for further consultation.4

Gastroenterology Advisor interviewed Cohen and Scarlata to learn more about these issues and how to address them in clinical practice.

Gastroenterology Advisor: Tell us a bit about the low-FODMAP diet and its role in IBS treatment.

Cohen: The LFD is known as an elimination diet, which means that foods or categories of foods are removed from one’s intake and then slowly added back in to gain a clearer picture of which foods are problematic for the individual. The goal of the LFD is to figure out which foods trigger an individual’s digestive problems and to create a diet that gives them all the nutrients they need but only includes the FODMAPs they can handle. FODMAPs exist in dairy, legumes, and many fruits and vegetables. This diet is useful for treating IBS by relieving digestion-related symptoms. 

Scarlata: The LFD is a 3-phase nutritional approach used to manage gastrointestinal symptoms in individuals with IBS, which can occur on its own or can co-occur in individuals with celiac disease and quiescent inflammatory bowel disease. This therapeutic diet has been shown to offer effective symptom management in 50% to 70% of those with IBS .3 Based on the data and clinical experience, abdominal pain and bloating seem to be the symptoms most effectively managed with this intervention. 

Gastroenterology Advisor: For which patients does this approach appear to be most suitable, and how might it be harmful to certain patients such as those with eating disorders?

Cohen: The diet is generally best used with individuals who have been diagnosed with IBS. For those with eating disorders or disordered eating behaviors, I would not recommend the LFD. It is very restrictive and can therefore be appealing to this population but can exacerbate restricting behaviors and therefore be counterproductive. While it is very common for eating disordered patients to have gastrointestinal issues when foods are reintroduced, these symptoms are usually temporary — unlike those of IBS — and improve with a structured meal plan that allows the body to adjust to eating and digesting foods again. The process can be painful, but it does get better over time.

Scarlata: In individuals experiencing malnutrition, major mental illness, an active eating disorder, or maladaptive eating such as in avoidant/restrictive feeding intake disorder, a diagnosis of eating or feeding disturbance due to lack of interest in eating, avoidance of sensory characteristics of food, and/or fear of adverse eating consequence such as digestive distress, engaging in a low-FODMAP elimination diet may escalate these conditions and would not be a suitable intervention.

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Gastroenterology Advisor: How should clinicians handle this issue in practice, including when to refer to other specialists?

Cohen: I would recommend that clinicians develop awareness of their patients’ eating patterns and screen for any disordered eating behaviors. Patients complaining of gastrointestinal distress should first be treated by a gastroenterologist. If clinicians suspect any disordered eating behaviors, the client should generally be treated by a team of clinicians who specialize in eating disorders, including dietitians who recognize the unique approaches and sensitivities required when working with these individuals.

Scarlata: In individuals with IBS, screening for an eating disorder or maladaptive eating is recommended prior to recommending the LFD. For physicians who may not have the time for a nutrition and behavioral assessment, an experienced registered dietitian can help make this determination. If a physician has a patient with an eating disorder or with escalated food fears, a trained eating disorder dietitian or therapist would be best suited to help that patient. Dietitians and mental health providers with this expertise can be found through the International Association of Eating Disorder Professionals and the International Federation of Eating Disorder Dietitians.

The majority of patients with IBS perceive food as a trigger to their — at times — debilitating symptoms. It is important to understand that some level of food fear may be present but not pathologic. When food fears or diet-related choices have a significant impact on the patient’s quality of life, exacerbate anxiety, or cause the person to fail to meet their nutritional needs, it is important that we provide supportive nutrition and behavioral interventions. Body mass index should not be the only metric to rely on to determine if eating disturbances are present. Psychological assessment, nutritional history, and food-related quality of life are equally important.

Eating disorders are on the rise globally.6 As practitioners, we all need to be more vigilant in screening our patients and help them get access to proper care. 

Gastroenterology Advisor: What are some of the most important remaining needs in this area?

Cohen: Many clinicians in the mental health field would benefit from continued education on the etiology and treatment of eating disorders. A team-based approach is essential as is ongoing collaboration and communication within the treatment team. 

References

1. Chey WD, Kurlander J, Eswaran S. Irritable bowel syndrome: a clinical review. JAMA. 2015;313(9):949-958.

2. National Institutes of Health–National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Irritable Bowel Syndrome. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/definition-facts. November 2017. Accessed September 27, 2019.

3. Scarlata K, Catsos P, Smith J. From a dietitian’s perspective, diets for irritable bowel syndrome are not one size fits all [published online August 19, 2019]. Clin Gastroenterol Hepatol. doi:10.1016/j.cgh.2019.08.018

4. Lenhart A, Ferch C, Shaw M, Chey WD. Use of dietary management in irritable bowel syndrome: results of a survey of over 1500 United States gastroenterologists. J Neurogastroenterol Motil. 2018;24(3):437-446.

5. Mari A, Hosadurg D, Martin L, Zarate-Lopez N, Passananti V, Emmanuel A. Adherence with a low-FODMAP diet in irritable bowel syndrome: are eating disorders the missing link? Eur J Gastroenterol Hepatol. 2019;31(2):178-182.

6. Galmiche M, Déchelotte P, Lambert G, Tavolacci MP. Prevalence of eating disorders over the 2000-2018 period: a systematic literature review. Am J Clin Nutr. 2019;109(5):1402-1413.