- Crohn’s disease is a chronic bowel condition, where management can involve lifestyle changes and several medications.
- Experts have been interested in how intermittent fasting may help people with Crohn’s disease.
- A randomized controlled trial found that eating within an eight-hour window helped reduce weight, lower disease activity, and improve inflammation in people with Crohn’s disease who have obesity or overweight.
A study published in Gastroenterology evaluated how time-restricted feeding (also called time-restricted eating), specifically eating only during an eight-hour window each day, affected individuals with Crohn’s disease.
The researchers found that it offered several benefits, including weight reduction and fewer Crohn’s symptoms, such as less abdominal discomfort.
The results suggest that time-restricted eating could help people with Crohn’s disease in multiple health aspects.
For this randomized controlled trial, researchers wanted to compare the use of time-restricted eating to a control group among individuals who had Crohn’s disease and also had overweight or obesity.
The authors explain that visceral fat, the deeper abdominal fat, can influence Crohn’s disease, such as by contributing to inflammation and heightened disease activity. As also noted in the study, time-restricted eating is a type of intermittent fasting, which can involve only eating in certain timeframes.
Researchers divided participants into an intervention group and a control group. All participants had Crohn’s disease that was in remission. Twenty participants were in the intervention group, and 15 participants were in the control group.
The intervention group participated in time-restricted eating: only eating during an eight-hour period and fasting the rest of the time for six days each week. While they were eating only during this time frame, they otherwise consumed their regular diet. Controls ate their usual food with no restrictions on when they could eat.
Participants in the intervention group had to keep track of the time frame for their eating and when they stopped. Researchers noted that participants adhered to time-restricted eating if they did so for at least five of the six required days each week.
Researchers evaluated participants at the start of the study and at 12 weeks. Participants were also contacted every other week to report on components like their symptoms. They also provided information on diet at baseline and at week twelve. Some participants received whole-body scans to evaluate fat and lean body mass.
Researchers also collected blood work and stool samples from participants.
Overall, the results showed several benefits in the intervention group. First, this group showed a decrease in body mass index compared to the control group. Since diets and energy intake were very similar between the two groups, the researchers suggest that this weight change was independent of diet quality or a decrease in calorie intake.
The activity of Crohn’s disease also decreased: stool frequency decreased by 40%, and abdominal discomfort was halved.
They also saw a decrease in critical molecules. For example, there was a decrease in leptin, which researchers note is “a marker of adiposity and inflammation.” In a subgroup, they also observed a decrease in visceral fat in the intervention group, whereas the control group showed an increase.
Further analysis showed that greater loss of body mass index was linked to pro-inflammatory and anti-inflammatory cytokines.
Gut health also appeared to improve in the intervention group, with increases in microbial diversity and taxa that produce short-chain fatty acids, which help regulate the gut. Researchers further found that some species increased as BMI decreased while others decreased, but these findings didn’t remain significant.
Study author Maitreyi Raman, MD, a gastroenterologist, clinician scientist, and associate professor of medicine at the University of Calgary, whose study was funded by Crohn’s Colitis Foundation and the Imagine Clinical Networks, explained the following:
“We show that clinical symptoms of CD [Crohn’s disease] improve with time-restricted eating, as do several systemic markers of inflammation. Participants in the time-restricted eating group had greater microbial diversity, and in participants who achieved at least one BMI point reduction, an increase in short-chain fatty acid-producing microbes was observed. Gut microbiome and immune interactions may contribute to intestinal inflammatory homeostasis restoration,” she told Medical News Today.
Babak Firoozi, MD, board certified gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, who was not involved in the study, also commented regarding the trial to MNT:
“Any non-pharmacologic strategy that improves both Crohn’s disease and overall health is meaningful. This study is the first randomized clinical trial to demonstrate a benefit of intermittent fasting in patients with Crohn’s disease. While a recent meta-analysis suggested similar outcomes, this trial provides more rigorous, high-quality evidence.”
How time restricted helps Crohn’s“The observed benefit is likely driven by significant weight loss and reduction in visceral fat. Visceral fat is known to promote systemic inflammation, so its reduction may help improve Crohn’s disease by lowering overall inflammatory burden.”
— Babak Firoozi, MD
This study does have several limitations. For one thing, it had a very small sample size and only lasted for twelve weeks. The authors note that these factors limit generalizability and support “interpretation as hypothesis-generating.”
The research also only included individuals who have obesity or overweight, so it’s unclear how helpful this method of intermittent fasting would be for people who are not in these categories. Researchers also used body mass index to determine overweight or obesity status, but this metric has some limitations. Data on diet were based on two 24-hour dietary recalls, so this and other participants’ reported data may contain errors.
This research was conducted in Canada, and participants were all between the ages of eighteen and seventy-five, which may also limit generalizability. One author received specific funding, though there were no declared conflicts of interest.
Researchers admit that weight loss was likely a factor in the benefits they observed, but they believe the results suggest that time-restricted feeding could play a unique role. Ultimately, more research on how time-restricted feeding relates to weight and Crohn’s disease will be helpful.
More research can build on these findings and explore more long-term benefits. Raman explained that “Future long-term studies are warranted to test the impact of intermittent fasting on long-term remission, and other outcomes of interest, including need for surgery, development of strictures, and hospitalization.”
This research introduces another possible strategy that could help in the long-term management of Crohn’s disease. The authors suggest that it could help people with Crohn’s disease maintain long-term remission.
“For now, intermittent fasting remains an effective tool to facilitate weight loss and reduce visceral fat in [people with obesity and overweight] with [Crohn’s], improve clinical symptoms and disease activity of [Crohn’s], and improve metabolic function,” Raman noted.
It’s critical for anyone considering intermittent fasting to first discuss options with their doctor to better understand the possible risks.
“For individuals living with Crohn’s disease, the foundation of care remains adherence to a healthy diet and consistent compliance with prescribed medications. For those who are overweight or have obesity-related conditions, addressing excess weight is especially important. In that context, intermittent fasting may be a valuable strategy worth discussing as part of a comprehensive management plan,” Firoozi told MNT.
