Effects of time-restricted eating on blood pressure in children: A cluster randomized controlled trial

Background This study aimed to evaluate the safety and efficacy of a time-restricted eating (TRE) intervention to reduce blood pressure (BP) in children and adolescents.Methods We conducted a 12-month, three-arm cluster-randomized controlled trial in two schools, with classes as the unit of randomization (91 classes). Children and adolescents with elevated BP were allocated to TREa (12-hour eating window with the last meal before 8:00 PM), TREb (12-hour eating window without a fixed last mealtime), or control (no time restriction). A total of 192 participants were enrolled and analyzed under an intention-to-treat framework (64 per group). Follow-up completion (retention) rates were 65.1% (125/192) at 6 months and 59.4% (114/192) at 12 months, corresponding to loss-to-follow-up rates of 34.9% (67/192) and 40.6% (78/192), respectively. Analyses used mixed-effects models accounting for clustering, with multiple imputations as a sensitivity analysis for missing data.Results After 12 months of intervention, both the TREa and TREb groups showed significant reductions in BP, with TREa demonstrating the most significant changes. Systolic blood pressure (SBP) decreased significantly in the TREa (−7.03 mmHg, 95%CI, −10.77 to −3.29 mmHg; P < 0.001) and TREb groups (−5.29 mmHg, 95%CI, −9.44 to −1.14 mmHg; P = 0.013). Diastolic blood pressure (DBP) changes in the TREa group were −4.09 mmHg (−6.80 to −1.38 mmHg; P < 0.001), with significantly different compared to the control group (P = 0.006).Conclusions A 12-hour eating window, particularly with the last meal completed before 8 PM, may be associated with lower BP over 12 months in children and adolescents with elevated BP; interpretation should consider the cluster design and attrition.Trial registration ChiCTR2400090073 (retrospectively registered on 23 September 2024).