Elimination diets have the potential to benefit patients with gastrointestinal diseases by reducing or curing their symptoms. However, the restrictive diets can be difficult to adhere to and contraindicated for patients with eating disorders, cautioned experts during the 2025 ASPEN Nutrition Science & Practice Conference, in Columbus, Ohio.
“There’s lots of disease states where we use elimination diets as a primary intervention, and there’s also a lot of disease states where diet is modulating disease. However, we always want to highlight that not all patients are appropriate for dietary intervention,” said Carolyn Newberry, MD, an assistant professor of medicine in the Division of Gastroenterology at Weill Cornell Medical Center, in New York City, where she serves as the director of GI nutrition within the Innovative Center for Health and Nutrition in Gastroenterology. “Even when appropriate, elimination diets should be tailored so that they are least burdensome for patients.”
Dr. Newberry and her co-presenters focused on the efficacy of elimination diets across GI disorders, including eosinophilic esophagitis (EoE) and irritable bowel syndrome (IBS).
Jennifer Katz, MD, an assistant professor of medicine at NYU Grossman School of Medicine and the director of enteral and parenteral nutrition at NYU Langone Health, in New York City, explained that elimination diets are a first-line treatment for EoE. According to a clinical decision support tool developed by the American Gastroenterological Association (AGA), an elemental diet, which is a type of elimination diet consisting of a liquid formula of complete nutrition, is more than 90% effective at causing histologic remission in EoE patients (Gastroenterology 2020;158[6]:1787). However, Dr. Katz warned that most patients won’t adhere to the diet long term.
Less restrictive than the elemental elimination diet is the six-food elimination diet (SFED), which removes milk, wheat, soy, eggs, nuts and seafood from a patient’s food intake. The AGA found that the SFED is 70% effective in inducing histologic response in adult EoE patients and 74% effective in pediatric populations. However, many patients don’t want to eliminate such broad categories of food, and Dr. Katz noted that doing so reduces adherence.
She added that step-up therapy, where two foods at a time are eliminated to achieve histologic response, is an option for EoE. A 2023 study found that starting with a two-food elimination diet was approximately 40% effective at inducing histologic response in EoE patients; a step-up to a four-food elimination diet and then, if necessary, SFED led to roughly 60% and 80% histologic response, respectively (Clin Gastroenterol Hepatol 2023;21[7]:1690-1698).
Unlike EoE, IBS cannot be cured; however, the fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, which eliminates these short-chain carbohydrates that the small intestine absorbs poorly, can be an important tool to alleviate some of the symptoms, Dr. Katz noted. If patients feel better with complete elimination of these sugars, each food is slowly reintroduced to identify foods that cause patients’ discomfort. A 2022 meta-analysis based on data from 13 randomized controlled trials found that a low-FODMAP diet was superior to any other dietary intervention for improvement in IBS symptoms (Gut 2022;71[6]:1117-1126).
Despite the potential benefit of elimination diets to treat GI diseases, Dr. Newberry warned that care teams must be cognizant of a patient’s baseline nutritional status, their history of disordered eating habits and the presence of any psychiatric disorders that may contraindicate dietary restrictions.
Dr. Newberry noted that traditional metrics to measure a patient’s relationship to food, such as body mass index, might be insufficient to uncover an eating disorder. She recommended the use of a nine-item avoidant restrictive food intake disorder (ARFID) screen as an alternative and effective tool to rule out patients for whom a restrictive diet may be contraindicated. However, she cautioned that use of the ARFID screen by physicians is likely to be insufficient to stop the rising incidence of disordered eating habits caused by social media and patients’ increased interest in restrictive diets. Dr. Newberry noted that close collaboration with nutritionists, pharmacists and interdisciplinary care teams who help communicate accurate information about elimination diets is essential for patients to be treated appropriately.
Echoing the Pharmacist’s Importance
Sara Bliss, PharmD, BCPS, BCNPS, BCCCP, FASPEN, a clinical pharmacist, nutrition support, at the University of North Carolina Medical Center, in Chapel Hill, who did not present on the panel, agreed with Dr. Newberry about the need for pharmacists to play an active role in helping patients find the expertise and care to identify diets that have the potential to treat GI disorders.
“Pharmacists are very available in the community setting and often field questions about medication and supplements,” she told Pharmacy Practice News. “[They] can help by recommending that patients seek out a registered dietitian to assist with appropriate implementation of elimination diets. This can help patients eliminate problem foods while maximizing nutrient-dense foods and maintaining [a healthy] nutrition status.”
Dr. Bliss reported no relevant financial disclosures. Dr. Katz reported that she was a NestlÉ Nutrition Fellow in 2022. Dr. Newberry reported that she is a consultant to Eli Lilly & Co.
This article is from the August 2025 print issue.