In the United States, obesity has become more prevalent among people with Crohn’s disease and ulcerative colitis — two conditions associated with inflammatory bowel disease (IBD). Several studies have reported that about 15 to 40 percent of people with IBD are obese.

Christopher Damman, MD, a clinical associate professor in the division of gastroenterology at the University of Washington in Seattle, says, “While there does seem to be a correlation between the two, it is not possible to say with the current data whether obesity causes greater severity or the other way around [more severe IBD causes obesity].”

Managing these two conditions at the same time can be challenging, no matter which one worsens the other, and requires medication, lifestyle changes, or both.

How Obesity May Compound Health Troubles

Some data shows excessive weight may intensify IBD symptoms, making treatments less effective and creating difficulties if surgery is needed.

Increased Inflammation

Obesity is linked with chronic low-grade inflammation in general, according to a study published in 2020 in Circulation Research.

Heightened inflammation may lead to more serious symptoms for people with IBD, such as severe abdominal pain and diarrhea. A paper published in 2023 in the World Journal of Gastroenterology, reviewing a range of research on this topic, reported that worsening inflammation related to obesity in patients with Crohn’s disease may further induce the formation of fistulas and strictures (a narrowing of the intestine due to scarring).

The same review cited evidence showing that every 5 kg/m2 increase in body mass index (BMI) above normal pushed the risk of Crohn’s disease up by 16 percent.

Less Effective Medications

Medications may not work as well for people who are obese. In a review published in 2020 in Clinical Gastroenterology and Hepatology, Siddharth Singh, MD, a gastroenterologist with UC San Diego Health in California, and his coauthors suggest that people who are obese may not respond to medication as robustly as people who aren’t obese, and they may lose response to therapy quickly.

Longer Hospital Stays

Obesity was associated with longer hospital stays in a comprehensive review published in 2021 of more than 61,000 inpatient admissions — primarily for ulcerative colitis. Researchers wrote that the “proinflammatory process induced by obesity may complicate the clinical picture of people with ulcerative colitis, interfere with biological treatment dosing, or worsen some of the side effects of systematic steroid use.”

“[Patients with IBD and obesity] may be more prone to hospitalization and spend more days in the hospital,” says Dr. Singh.

More Risks Related to Surgery

Patients with obesity are more likely to experience postoperative complications if surgery is required to treat their IBD.

“Operations just tend to be a lot more difficult with [patients with obesity] — complication rates go way up,” says Dr. Damman. “That’s why surgeons will always ask their patients to lose weight before surgery, because it makes for better outcomes.”

Damman warns that some of the complications include infection at the site of surgery and incisions not healing well. People who are obese may also have problems during surgery related to heart disease, higher rates of respiratory infection, and higher rates of blood clots.

However, surgery may be the only option for some individuals who are obese and have had no success with diet, exercise, or medication.

Exploring Medication Options

There are more options than ever when it comes to IBD medications, but Damman notes that some may contribute more to weight gain than others. Make sure to speak with your healthcare provider, who can advise you on treatments based on your weight, disease activity, and other factors. In some cases, the weight increase will be a sign that the medications are having the desired effect and helping the body absorb nutrients.

Oral Corticosteroids

These medications (prednisone is an example) have been used to induce remission in patients with IBD for more than 60 years, as they have strong anti-inflammatory effects.

They can, however, alter your metabolism, causing you to have a greater appetite and therefore gain weight.

Tumor Necrosis Factor (TNF)–Alpha Inhibitors

These suppress part of the inflammatory response related to the protein TNF. TNF-alpha inhibitors treat moderate to severe IBD

and include adalimumab (Humira), certolizumab pegol (Cimzia), golimumab (Simponi), and infliximab (Remicade).

The weight gain risks may vary from drug to drug. Research has shown that body weight over time is more likely to rise among people receiving infliximab, compared with those receiving adalimumab, for instance.

Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists

Recently, more people have been turning to drugs such as Ozempic (approved for people with type 2 diabetes and heart disease) and Wegovy (approved for people who are overweight and have related health problems) for weight loss. Both medications are GLP-1 receptor agonists and contain the same active ingredient (semaglutide). GLP-1 receptor antagonists are also now indicated for sleep apnea, a condition often comorbid with obesity.

Research on how well these drugs work to treat IBD is still in the early stages. However, a study published in 2021 in eClinicalMedicine looked at more than 3,700 people with IBD and type 2 diabetes who were taking a GLP-1 and concluded that these therapies may improve the disease course of IBD. The scientists observed a decreased risk of hospitalization and the need for oral steroid treatment (a common therapy for IBD) among those taking a GLP-1. Their study also reported that GLP-1 receptor agonists may reduce systemic inflammation indirectly through improved glucose regulation and weight loss.

Lifestyle Approaches to Help Improve IBD and Obesity

Drugs to treat IBD are often essential for controlling symptoms, but lifestyle changes can help people reduce symptoms and maintain a healthy weight.

Physical Activity

Aiming for 30 minutes of moderate exercise each day can make a difference. Exercises such as walking, jogging, and lifting weights not only help fight obesity — they may also help reduce stress, lower inflammation, decrease disease activity, improve skin, reverse muscle weakness, and strengthen bones and the immune system.

Diet

IBD flare-ups can be triggered by certain foods, but following a healthy eating plan, such as the Mediterranean diet, is beneficial, and it can help control weight as well. The Crohn’s and Colitis Foundation details a number of diets that have been proven to be successful, depending on the patient’s specific symptoms.

For example, the IBD anti-inflammatory diet is designed to restore balance between helpful and harmful bacteria, while promoting good nutrition. The eating strategy includes probiotics with live good bacteria (such as plain yogurt, kefir, and kimchi) and foods that maintain good intestinal bacteria (such as oats, bananas, garlic, and onions). However, scientific evidence to support whether this specific diet maintains remission and prevents the relapse of IBD is limited.

There’s also the specific carbohydrate diet, which may ease the symptoms of IBD and promote weight loss by eliminating sugars and hard-to-digest carbs like grains and grain products.

Gut Microbiome

Exercise and a healthy diet can also help promote a diverse gut microbiome (the ecosystem of bacteria and other microbes that live in your intestines). Both obesity

and IBD

have been linked to having a less diverse mix of microbes in the gut. This lack of diversity could affect the natural production of molecules that help control obesity and IBD, such as the fatty acid butyrate.

“Molecules that make butyrate could actually play a role in preventing obesity and potentially inflammatory bowel disease as well,” says Damman.

Sleep and Stress

Research has revealed that poor sleep is associated with disease activity and obesity. Stress can also fuel both obesity and IBD symptoms.

“In addition to medications and therapies for their specific condition, lifestyle habits are the most important factors,” says Damman, who is also the author of the gut health blog Gut Bites. “Eating well, exercise, sleeping well, and managing stress can all make a difference.”

Ira Daniel Breite, MD

Medical Reviewer

Castle Connolly Top Doctor

Ira Daniel Breite, MD, is a board-certified internist and gastroenterologist. He is an associate professor at the Icahn School of Medicine at Mount Sinai, where he also sees patients and helps run an ambulatory surgery center.

Dr. Breite divides his time between technical procedures, reading about new topics, and helping patients with some of their most intimate problems. He finds the deepest fulfillment in the long-term relationships he develops and is thrilled when a patient with irritable bowel syndrome or inflammatory bowel disease improves on the regimen he worked with them to create.

Breite went to Albert Einstein College of Medicine for medical school, followed by a residency at NYU and Bellevue Hospital and a gastroenterology fellowship at Memorial Sloan Kettering Cancer Center. Working in city hospitals helped him become resourceful and taught him how to interact with people from different backgrounds.

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Don Rauf

Author

Don Rauf has been a freelance health writer for over 12 years and his writing has been featured in HealthDay, CBS News, WebMD, U.S. News & World Report, Mental Floss, United Press International (UPI), Health, and MedicineNet. He was previously a reporter for DailyRx.com where he covered stories related to cardiology, diabetes, lung cancer, prostate cancer, erectile dysfunction, menopause, and allergies. He has interviewed doctors and pharmaceutical representatives in the U.S. and abroad.

He is a prolific writer and has written more than 50 books, including Lost America: Vanished Civilizations, Abandoned Towns, and Roadside Attractions. Rauf lives in Seattle, Washington.

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Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Resources

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