Summary:
Some literature suggests that excess visceral fat and metabolic dysfunction may worsen inflammatory bowel disease, and emerging evidence suggests that when food is consumed, rather than just what, may influence immune and metabolic pathways. This study was a randomized controlled trial that looked at whether time-restricted feeding could improve health outcomes in adults with Crohn’s disease who were overweight or obese. Participants were assigned to follow either an 8-hour daily eating window or a usual eating pattern. Over the intervention period, those in the time-restricted group experienced reductions in body mass index, visceral adiposity, systemic inflammation, and clinical disease activity compared with controls. The improvements occurred despite similar food types and calorie intake between groups, suggesting that meal timing itself may have contributed to the observed effects. Participants practicing time-restricted feeding also showed reductions in abdominal symptoms and inflammatory markers, alongside modest weight loss. These findings support the hypothesis that aligning food intake within a limited daily window may beneficially influence metabolic and immune regulation and that time-restricted feeding may be a promising adjunct strategy for adults with Crohn’s disease and excess weight.
Abstract:
Overweight and obesity (OO) affect approximately 40% of individuals with Crohn’s disease (CD).1 Visceral adiposity (VAT) is particularly detrimental, contributing to metabolic alterations, systemic inflammation, and adverse clinical outcomes, including reduced response to biologic therapies, increased disease activity, poor quality of life, and increased risk of surgical complications.2 Despite the high prevalence of OO in inflammatory bowel disease (IBD), lifestyle interventions specifically targeting adiposity and metabolic dysfunction remain underexplored. Time-restricted feeding (TRF), a form of intermittent fasting, confines food intake to a defined window (8 hours), followed by fasting for the remaining hours (16 hours). In the general population, intermittent fasting, including TRF, has demonstrated consistent metabolic and anti-inflammatory effects, including reductions in VAT, insulin resistance, and circulating cytokines, independent of calorie restriction.3,4 These finding suggest that TRF may influence immunometabolic pathways beyond weight loss alone. However, no controlled studies have evaluated TRF in patients with IBD, a population characterized by chronic inflammation, immune dysregulation, and altered gut microbiota. To address this gap, we conducted a 12-week randomized controlled trial to evaluate the effects of TRF on clinical disease activity, body composition, and systemic inflammation in adults with CD in clinical remission and OO. Participants were randomized to a TRF group (n = 20) or a control group (n = 15). The TRF group fasted for 16 consecutive hours per day, 6 days per week, while consuming their habitual diet within an 8-hour eating window. Controls continued their usual unrestricted eating pattern. Weight and height were measured to calculate body mass index (BMI). Stool samples were collected for fecal calprotectin and microbiota analyses, and serum samples were assessed for immune-metabolic biomarkers at baseline and week 12. Baseline cohort characteristics are summarized in Supplementary Table 1. Over 12 weeks, BMI decreased significantly in the TRF group compared with controls (Δ –0.9 ± 0.03 kg/m2 vs +0.6 ± 0.3 kg/m2; P < .001) (Figure 1A). Energy intake and diet quality (Mediterranean Diet Index) did not differ between groups or across time (Supplementary Figure 1A and B), suggesting that BMI reduction occurred independent of caloric restriction and diet quality. Mean ± SD adherence in the TRF group was 95% ± 8%. Clinical disease activity, measured by the Harvey–Bradshaw Index, also improved significantly in the TRF group (Δ –2 ± 4 vs –0.5 ± 2; P = .02) (Figure 1B), with a 40% decrease in stool frequency and 50% reduction in abdominal discomfort, which was not observed in controls.
Article Publication Date: 9/2/2026
DOI: 10.1053/j.gastro.2025.11.008
