Article Impact Level: HIGH Data Quality: STRONG Summary of Nature Communications, 16(1), 3186. https://doi.org/10.1038/s41467-025-57846-y Dr. Sarah L. Chellappa et al.
Points
- This study explored the impact of meal timing on cardiovascular effects caused by circadian misalignment in non-shift workers, using a Nighttime Meal Control Group and a Daytime Meal Intervention Group.
- The Daytime Meal Intervention Group showed no significant changes in cardiovascular measures, suggesting a protective effect of eating during the daytime. At the same time, the Nighttime Meal Control Group had significant adverse cardiovascular effects.
- The Nighttime Meal Control Group experienced a 25.7% decrease in pNN50, a 14.3% decrease in RMSSD, a 5.5% increase in LF/HF, and a 23.9% increase in PAI-1 after simulated night work.
- The Daytime Meal Intervention Group showed a 6-8% reduction in blood pressure, while the control group showed no significant change, highlighting the benefits of daytime meal timing for cardiovascular health.
- These findings suggest that eating during the daytime, even with mistimed sleep, can reduce the adverse cardiovascular effects of circadian misalignment, offering potential behavioral strategies for shift workers to mitigate cardiovascular risks.
Summary
This study investigates the impact of meal timing on mitigating cardiovascular effects caused by circadian misalignment, a common issue for night shift workers or individuals experiencing jet lag. A total of 20 healthy non-shift workers were randomly assigned to either a Nighttime Meal Control Group, where they ate during both day and night or a Daytime Meal Intervention Group, where they consumed meals only during the daytime. The primary outcomes measured were pNN50 (percentage of consecutive heartbeat intervals >50 ms), RMSSD (root mean square of successive heartbeat differences), and LF/HF (low/high cardiac frequency). The secondary outcome was plasminogen activator inhibitor-1 (PAI-1), a prothrombotic factor.
The study found that the Daytime Meal Intervention Group showed no significant changes in cardiovascular measures compared to baseline, suggesting a protective effect of eating during the daytime. In contrast, the Nighttime Meal Control Group demonstrated significant adverse effects after simulated night work. Specifically, there was a 25.7% decrease in pNN50 (pFDR = 0.008), a 14.3% decrease in RMSSD (pFDR = 0.02), a 5.5% increase in LF/HF (pFDR = 0.04), and a 23.9% increase in PAI-1 (pFDR = 0.04). These changes indicate a detrimental impact on cardiac vagal modulation and increased prothrombotic factors.
Additionally, the intervention group experienced a significant reduction in blood pressure by 6-8% (P < 0.01), whereas the control group showed no significant change in blood pressure (P < 0.05). There were no significant effects on heart rate or cortisol levels. These results suggest that eating only during the daytime, despite mistimed sleep, can mitigate some of the adverse cardiovascular effects of circadian misalignment, offering potential behavioral strategies for shift workers to reduce cardiovascular risks.
Link to the article: https://www.nature.com/articles/s41467-025-57846-y
References Chellappa, S. L., Gao, L., Qian, J., Vujovic, N., Li, P., Hu, K., & Scheer, F. A. J. L. (2025). Daytime eating during simulated night work mitigates changes in cardiovascular risk factors: Secondary analyses of a randomized controlled trial. Nature Communications, 16(1), 3186. https://doi.org/10.1038/s41467-025-57846-y
