Time-Restricted Feeding Improves Adiposity and Disease Activity in Adults With Crohn’s Disease

For many years, nutritional management in Crohn’s disease has emphasized preventing undernutrition. However, overweight and obesity now affect an estimated 40 percent of patients, introducing metabolic factors that may influence inflammation, treatment response, and clinical outcomes. New randomized trial data suggest that the timing of food intake, independent of calorie reduction, may play a measurable role in this context.

In a 12-week randomized controlled study published in Gastroenterology, researchers evaluated the effects of time-restricted feeding (TRF) on body composition, immune-metabolic markers, and clinical disease activity in adults with Crohn’s disease who were overweight or obese and in clinical remission . TRF is a form of intermittent fasting that limits daily food intake to a defined window—in this study, eight hours—followed by a 16-hour fasting period.

Thirty-five participants were randomized to either a TRF intervention or a control group that maintained an unrestricted eating pattern. Those in the intervention group followed TRF six days per week while continuing their habitual diet, without prescribed caloric restriction or changes in diet quality. This design allowed investigators to assess the effects of meal timing itself rather than weight loss driven by reduced intake.

At 12 weeks, participants assigned to TRF experienced a statistically significant reduction in body mass index compared with controls, whose BMI increased modestly over the same period. Among participants who underwent dual-energy X-ray absorptiometry, visceral adipose tissue decreased in the TRF group and increased in the control group, resulting in a significant between-group difference. Visceral adiposity has been associated with metabolic dysfunction and poorer outcomes in Crohn’s disease, including diminished response to biologic therapies.

Clinical disease activity also differed between groups. Scores on the Harvey–Bradshaw Index declined in the TRF group, accompanied by reductions in stool frequency and abdominal discomfort, whereas no comparable changes were observed in controls. Measures of systemic and intestinal inflammation, including C-reactive protein and fecal calprotectin, remained largely unchanged in both groups, suggesting that the observed clinical improvements occurred without detectable changes in these markers over the study period.

The intervention was also associated with changes in circulating adipokines linked to adipose tissue and immune signaling. Serum leptin, plasminogen activator inhibitor-1, and adipsin levels decreased significantly in the TRF group but not in controls. Leptin, which is produced by adipose tissue and involved in immune regulation, declined in parallel with reductions in BMI and visceral fat.

Exploratory cytokine analyses within the TRF group showed that participants who achieved greater BMI reductions exhibited correlations with both anti-inflammatory cytokines, such as interleukin-4 and IL-1 receptor antagonist, and selected pro-inflammatory cytokines, including IL-2 and IL-12 isoforms. The authors note that this pattern may reflect changes in immune signaling associated with metabolic alterations, though the clinical implications remain uncertain.

Gut microbiota analyses suggested additional biological effects. Within the TRF group, investigators observed trends toward increased microbial diversity and relative enrichment of short-chain fatty acid–producing taxa, including Butyricimonas synergistica and Odoribacter splanchnicus. Associations were also identified between BMI reduction and the relative abundance of specific bacterial species, although these findings did not remain significant after correction for multiple comparisons and were considered exploratory.

The authors describe the study as hypothesis-generating, citing its modest sample size and short duration as limitations. Nonetheless, the results indicate that time-restricted feeding was feasible, well adhered to, and associated with improvements in body composition and clinical disease activity in adults with Crohn’s disease who were overweight or obese.

Further studies in larger and more diverse populations will be needed to clarify the durability of these effects, determine whether benefits are independent of weight loss, and assess potential implications for long-term disease management.