EATING within a daily eight-hour window may significantly ease Crohn’s disease symptoms, with a Canadian randomised trial showing intermittent fasting reduced disease activity by 40% and halved abdominal discomfort within just 12 weeks.
Why Intermittent Fasting Is Being Tested in Crohn’s Disease
Intermittent fasting, particularly time restricted feeding, has demonstrated metabolic and anti-inflammatory benefits in the general population, independent of calorie reduction. These effects include improvements in visceral fat, insulin resistance, and inflammatory signalling. Until now, however, controlled trials had not examined whether intermittent fasting could safely influence disease activity and immune health in people living with Crohn’s disease, despite growing interest in lifestyle-based interventions.
Trial Results Show Reduced Symptoms with Intermittent Fasting
The 12-week randomised controlled trial included 35 adults with Crohn’s disease who were overweight or living with obesity. Participants were assigned either to intermittent fasting through time restricted feeding, eating all meals within an eight-hour window while fasting for 16 hours, or to a control group continuing their usual diet. Body mass index decreased significantly in the intermittent fasting group compared with controls (Δ –0.9 ± 0.03 kg/m2 vs +0.6 ± 0.3 kg/m2; P < .001). Clinical disease activity, measured using the Harvey Bradshaw Index, also improved (Δ –2 ± 4 vs –0.5 ± 2; P = .02). Stool frequency fell by 40% and abdominal discomfort by 50%, while participants lost an average of 5.5 pounds compared with an average of 3.7 pounds gained in the control group. Importantly, these improvements occurred without changes in calorie intake or diet quality.
Clinical Implications and Future Research Directions
The findings suggest intermittent fasting may offer a feasible adjunctive strategy for symptom control in Crohn’s disease. Reductions in inflammatory adipokines such as leptin and plasminogen activator inhibitor 1 point to broader immunometabolic benefits that could support long term disease management. However, markers such as C reactive protein and fecal calprotectin did not change significantly, indicating symptom improvement rather than full inflammatory resolution. Larger and longer studies are now needed to confirm durability, assess safety across diverse patient groups, and clarify whether intermittent fasting could help maintain remission alongside standard medical therapy.
Reference
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. 2026;doi:10.1053/j.gastro.2025.11.008.
