The TIDIER Trial: A randomized, phase II clinical trial of time-restricted eating versus nutritional counseling among patients receiving radiation or chemoradiation for prostate, cervical or rectal cancer

BackgroundRadiation therapy (RT) is an essential component of definitive treatment for cancers of the prostate, rectum, cervix, and other pelvic malignancies. Despite its proven efficacy, pelvic RT is associated with a constellation of adverse effects, collectively referred to as pelvic radiation disease (PRD). Several clinical and preclinical studies have shown that dietary interventions, including time-restricted eating (TRE), may represent a novel approach to mitigate radiation and chemotherapy toxicity and, in some cases, promote oncologic efficacy, thereby enhancing quality of life, reducing morbidity and mortality, and improving disease outcomes. ObjectivesThis trial was designed to evaluate TRE feasibility/tolerability and test the hypothesis that TRE during RT or chemoradiation could reduce DNA damage accumulation in peripheral blood mononuclear cells over the course of treatment, as quantified by {gamma}H2AX foci. Secondary objectives include reduction in clinically observed toxicities, improvements in urinary or blood biomarkers of DNA damage, mitigation of microbiome dysbiosis and cytokine response during radiation, and improved metabolic parameters. MethodsA total of 48 individuals with prostate, cervical, or rectal cancer aged [≥]18 years with a BMI [≥]21 kg/m2 receiving pelvic radiation will be randomized to either TRE or nutritional counseling. Both groups of participants will receive dietary consultation with a registered dietician before and during RT, and the TRE group participants will be asked to restrict their caloric intake to a specific timeframe (fast at least 6-8 hours before and at least 4-6 hours after RT). Biospecimens (blood, urine, stool), quality-of-life surveys, physician-reported toxicities (CTCAEv5.0), and food intake and fasting logs will be collected biweekly during the study intervention and every 3-6 months up to one year follow-up. ResultsAccrual was completed in August 2025. Follow-up and biospecimen collection are ongoing, and correlative analyses are in progress. Final outcomes will be reported upon study completion. Trial registrationClinicalTrials.gov NCT05722288