A groundbreaking dietary approach has emerged as a potential game-changer for individuals battling Crohn's disease. This new strategy, involving intermittent calorie restriction, has shown remarkable promise in managing the symptoms and biomarkers associated with this condition.
A recent study from the US has revealed that a short-term, calorie-restrictive diet can significantly improve both the physical symptoms and biological indicators of mild-to-moderate Crohn's disease. The diet, which only requires participants to restrict their calorie intake for five days each month, has led to impressive results. After just three months, participants experienced significantly higher rates of clinical response and remission.
The study, a controlled clinical trial, involved 100 participants who were randomly assigned to either a fasting-mimicking diet (FMD) or their regular diet for three consecutive months. The researchers measured changes in the CD Activity Index (CDAI) and inflammatory biomarkers to compare the two groups. The results were astonishing: nearly 70% of the FMD group achieved a clinical response, defined as a reduction in CDAI of at least 70 points, compared to less than 44% in the control group. Furthermore, around 65% of the FMD group reached clinical remission, indicated by a CDAI of 150 or less, while only 38% of the control group achieved this milestone.
The diet cycle involved consuming 700 to 1100 calories per day for five consecutive days each month, followed by a return to their regular diet for the remainder of the month. During the calorie-restricted periods, participants were provided with plant-based meals.
One of the key biomarkers, faecal calprotectin, which indicates inflammation, showed a significant improvement at the end of the third diet cycle. The FMD group experienced a mean reduction of 22%, while the control group saw an 8% mean increase. Additionally, nearly 40% of the FMD group had a remarkable decline of 50% or more in faecal calprotectin levels, compared to just 6% in the control group.
Another important biomarker, C-reactive protein, also showed a positive trend, with a 1% reduction in the FMD group and a 37% increase in the control group. Although this difference narrowly missed statistical significance, it still highlights the potential benefits of the diet.
Professor Sidhartha Sinha, the senior author and assistant professor of gastroenterology and hepatology at Stanford University, expressed surprise and delight at the results. "We noticed that even after just one FMD cycle, there were clinical benefits."
The authors acknowledged the challenges of studying dietary interventions due to self-reporting and the inability to blind participants. However, this trial successfully demonstrated improvements in objective markers of inflammation and symptom relief.
Interestingly, less than half of the control group experienced symptom improvements, which researchers attributed to natural symptom fluctuations in Crohn's disease and the effectiveness of standard care and medications.
Following a three-month washout period after the third FMD cycle, the clinical response and remission rates were similar between the groups. This suggests that the optimal number of FMD cycles needed to maintain long-term benefits is still unclear, and continuing cycles may be necessary for sustained remission.
The study also revealed that participants with mild Crohn's disease achieved greater clinical response with FMD compared to the control diet (75% vs 48%), as did those with moderate CD (57% vs 11%). Additionally, participants with colonic disease had a higher rate of clinical response with FMD (82% vs 33%), as did those with ileocolonic disease (71% vs 30%), but not those with isolated ileal disease (56% vs 60%).
Furthermore, FMD was more effective than the control diet for participants who were not on any medical therapy (77% vs 33%). The mean age of participants was 45 years, and at the study's baseline, around 40% of both groups had an overweight BMI. The control group had a higher proportion of participants with obesity (31% vs 15%) and fewer females (56% vs 80%) compared to the FMD group.
Throughout the study, there was no significant difference in therapy escalation, such as corticosteroid prescription or dose escalation of advanced therapy, between the two groups (28% FMD vs 25% control). While some in the FMD group experienced fatigue and headaches, no serious side effects were reported.
This innovative dietary approach offers a new ray of hope for individuals living with Crohn's disease. However, it is important to note that further research is needed to fully understand the long-term effects and optimal implementation of this diet.
Nature Medicine, 13 January 2026 (https://www.nature.com/articles/s41591-025-04173-w)
