Is Intermittent Fasting a Good Idea if You Have Crohn’s?
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Should You Try Intermittent Fasting if You Have Crohn’s?

Should You Try Intermittent Fasting if You Have Crohn’s?
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Updated on May 8, 2026
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Fasting isn’t new, but that hasn’t stopped intermittent fasting (IF) from becoming one of the decade’s most popular diet trends. IF (often used interchangeably with the terms “time-restricted feeding” and “time-restricted eating”) is an eating pattern in which a person eats only during a window lasting a certain number of hours in a day, then fasts for the rest of the time, often immediately following dinner and into part of the next day.

Research has shown that IF can have benefits for some people, by helping them regulate their blood sugar levels, lose weight, and be healthier overall. According to one small study of people in remission from Crohn’s disease who were overweight or had obesity, fasting for 16 hours a day for 12 weeks led to significant reductions in body mass index (BMI), the frequency of bowel movements, and abdominal discomfort.

However, a review of studies of people who were overweight or had obesity but did not have Crohn’s found that, compared with following traditional advice on dieting like restricting calories, IF may make little to no difference on weight loss or quality of life.

Just because some studies back up benefits to intermittent fasting, it doesn’t necessarily mean that IF is right for everyone, especially people with an inflammatory bowel disease (IBD) such as Crohn’s. Here’s why people with Crohn’s need to speak with their doctor before trying this diet trend.

Intermittent Fasting and IBD: The Debate

While there’s research showing that intermittent fasting may benefit some people in the general population, studies involving people with Crohn’s and ulcerative colitis are lacking.

“Some studies have shown that intermittent fasting or time-restricted feeding may decrease inflammation and improve gut microbiome health,” says Kelly Kennedy, RDN, of Bousquet Sport in Pittsfield, Massachusetts, who was previously on staff at Everyday Health. “But this research is still in its infancy.”

In the aforementioned randomized, controlled trial of people in remission from Crohn’s who were overweight or had obesity, 20 people followed a time-restricted feeding pattern for 12 weeks. They ate only during an eight-hour window and fasted the other 16 hours of the day, six days a week. A control group of 15 participants did not follow this eating pattern.

Those following IF saw a significant decrease in their BMI, a 40 percent reduction in bowel movement frequency, and a 50 percent decrease in abdominal discomfort; the control group didn’t see these benefits. The IF group also saw significant reductions in leptin, a chemical marker of inflammation. At the end of the study, however, there were no differences in C-reactive protein or fecal calprotectin levels (chemicals that indicate the presence of inflammation) between the IF group and the control group.

“This was an intriguing and well-done study that, combined with other recent studies, suggests that there may be a role for intermittent fasting, or time-restricted eating, in inflammatory bowel disease,” says Bharati Kochar, MD, a gastroenterologist at the Crohn’s and Colitis Center at Massachusetts General Hospital in Boston. “Previous studies have shown the anti-inflammatory benefits of time-restricted eating in mice models, but we also know that in IBD, interventions that work in mice don’t always work in humans.”

And previous research on humans hasn’t always shown the same positive results as the randomized, controlled trial, either. “One study of patients with IBD who fasted during Ramadan found that some people with ulcerative colitis actually had worse symptoms, while people with Crohn’s disease did not see much change,” says Bincy Abraham, MD, a gastroenterologist and the director of the Fondren Inflammatory Bowel Disease Program at Houston Methodist Hospital's Underwood Center. In fact, participants over age 30 and those with higher levels of gut inflammation before fasting were more likely to feel worse, says Dr. Abraham.

Another study that tracked 100 people with Crohn’s disease in remission during Ramadan found that 94 percent saw an improvement of symptoms during daytime fasting hours. But there was no control group for comparison, and it’s unclear which symptoms improved and by how much.

“The differences are likely from factors such as whether the disease is in remission or active, a person’s weight and overall health, and the specific type of fasting used,” says Abraham.

Should You Try Intermittent Fasting if You Have Crohn’s?

Given the lack of large-scale research and potential negative effects of IF, experts are hesitant to recommend it for people with Crohn’s disease. They also cite that those with Crohn’s may already be underweight or deficient in certain nutrients. One research review notes that the risk of nutrient deficiencies includes people who are overweight or have obesity, since IBD affects nutrient absorption.

“Limiting the amount of time you eat each day — or even the number of days per week — also limits the number of opportunities you have to get calories, vitamins, and minerals into your body,” Kennedy says. “This isn’t a good idea for anyone who is underweight.”

Many people with Crohn’s are also deficient in vitamin D, says Jill Gaidos, MD, a gastroenterologist at Yale New Haven Health in Connecticut and the director of clinical research for Yale’s IBD program. While vitamin D can be hard to get from food — it’s called the Sunshine Vitamin because your body makes it when you’re exposed to the sun — it can be found in fortified dairy foods, such as milk and yogurt. But people with Crohn’s may avoid dairy products because they have trouble digesting lactose, a naturally occurring sugar found in dairy.

People with Crohn’s may also be iron deficient. About 1 in 3 people with IBD have anemia, a condition in which a person doesn’t have enough healthy red blood cells or hemoglobin (a protein in red blood cells), which carry oxygen throughout the body. The most common cause of anemia is a low level of iron.

“This also brings up concerns about triggering unhealthy relationships with food, especially in younger people or those with a history of disordered eating,” says Abraham.

She recommends that people avoid IF during a flare, because the eating pattern can increase the risk of dehydration and electrolyte imbalances. If you have strictures, are at risk for a bowel obstruction, or have had major intestinal surgery, Abraham says you should avoid IF, too. If you’re overweight or have obesity, are in remission from Crohn's, have a stable medication regimen, and are getting adequate nutrients, she says you might be a candidate for IF.

Always talk to your doctor first if you’re thinking about trying IF, however.

“If a Crohn’s patient is trying intermittent fasting, I would certainly recommend working with a registered dietitian-nutritionist who specializes in digestive conditions,” says Kennedy. “It’s important that their weight and diet be tracked even more closely than is usually recommended while on IF.”

If IF is causing you to lose out on vitamins and minerals, or if it is complicating your Crohn’s symptoms, you should stop, she says.

And if you are modifying your diet in the hope of better control over your symptoms, keep in mind that it’s not a substitute for medications and shouldn’t be used to treat intestinal inflammation, Dr. Gaidos says.

Rather than recommending fasting, Gaidos tells people who have Crohn’s to eat a well-balanced, healthy diet that is low in processed foods and sugar. Diets lower in indigestible fiber may also be easier for your body to handle.

Resources We Trust

Additional reporting by Laura Casey.

EDITORIAL SOURCES
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
  1. What Is Intermittent Fasting? Cleveland Clinic. January 26, 2026.
  2. What Is Intermittent Fasting? Does It Have Health Benefits? Mayo Clinic. March 8, 2025.
  3. Haskey N et al. Time-Restricted Feeding Reduces Body Mass Index, Visceral Adiposity, Systemic Inflammation, and Clinical Disease Activity in Adults With Crohn’s Disease: A Randomized Controlled Study. Gastroenterology. May 2026.
  4. Garegnani LI et al. Intermittent Fasting for Adults with Overweight or Obesity. Cochrane Database of Systematic Reviews. February 16, 2026.
  5. Semnani-Azad Z et al. Intermittent Fasting Strategies and Their Effects on Body Weight and Other Cardiometabolic Risk Factors: Systematic Review and Network Meta-Analysis of Randomised Clinical Trials. The BMJ. June 18, 2025.
  6. Haasis E et al. Effect of Intermittent Fasting on Immune Parameters and Intestinal Inflammation. Nutrients. November 19, 2024.
  7. Negm M et al. Effect of Ramadan Intermittent Fasting on Inflammatory Markers, Disease Severity, Depression, and Quality of Life in Patients With Inflammatory Bowel Diseases: A Prospective Cohort Study. BMC Gastroenterology. April 24, 2022.
  8. El Mountassir M et al. Impact of Ramadan on Crohn's Disease. Gastroenterology, Hepatology and Endoscopy. February 19, 2021.
  9. Sannidhi D et al. Lifestyle Medicine for Obesity in the Era of Highly Effective Anti-Obesity Treatment. Nutrients. July 21, 2025.
  10. Vitamin D. Office of Dietary Supplements. June 27, 2025.
  11. Food. Crohn’s & Colitis UK. April 2025.
  12. Anemia Fact Sheet. Crohn’s & Colitis Foundation.
  13. Anemia: Symptoms & Causes. Mayo Clinic. May 5, 2026.
  14. Nutrition and Crohn’s Disease. University of Virginia Health System. March 2024.
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