A large French study links inconsistent weekday and weekend meal schedules with increased cardiovascular risk, particularly among men.
Frequently changing meal times between working days and weekends could be associated with a higher risk of cardiovascular disease, according to a major French study.
Researchers analysed data from 104,806 adults enrolled in the NutriNet-Santé cohort. Participants recorded detailed dietary intake and meal timings on multiple days, allowing researchers to compare their weekday and weekend eating schedules. Health outcomes were monitored between 2009 and 2023.
The researchers described substantial differences between weekday and weekend meal timings as “eating jetlag.” Similar to sleep-related social jetlag, it may interfere with the body’s circadian rhythms—the internal biological clocks that help regulate metabolism, blood pressure and other cardiovascular processes.
Among male participants, every additional hour of difference in meal timing was reportedly associated with a 14% higher risk of overall cardiovascular disease and a 21% higher risk of coronary heart disease. The associations remained after the researchers considered factors including diet quality, sleep duration, smoking and socioeconomic status.
The study did not identify a statistically significant association among women. Researchers said this could reflect biological differences, lower exposure to disruptive work schedules or differences in the participants’ underlying cardiovascular risk.
The findings do not prove that irregular meal schedules directly cause heart disease. This was an observational study, meaning unmeasured lifestyle or health factors could have influenced the results. The researchers therefore called for additional studies before firm clinical recommendations are made.
Nevertheless, the findings indicate that when people eat may deserve greater attention alongside what they eat. Maintaining reasonably consistent breakfast, lunch and dinner timings throughout the week could help support the body’s natural circadian rhythm.
People working night or rotating shifts may find regular schedules difficult to maintain. Rather than making drastic dietary changes, they could discuss practical meal-planning strategies with a qualified doctor or dietitian, particularly if they already have cardiovascular risk factors.
The research was published in the peer-reviewed journal Communications Medicine. Read the original study
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