Men whose meals slide later or earlier on the weekend show a measurably higher risk of heart disease than those who eat on a steady schedule, a large French cohort study finds.
Each additional hour of "eating jetlag" was linked to a 14 percent higher risk of cardiovascular disease and a 21 percent higher risk of coronary heart disease in men.
The study was published in Communications Medicine on September 2, 2026, by researchers from INRAE, Inserm, Sorbonne Paris Nord University, Université Paris Cité and the CNAM.
It is the first prospective analysis to test whether weekend-versus-weekday meal timing, on its own, tracks with cardiovascular outcomes.
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What eating jetlag actually means
Eating jetlag is the difference between the midpoint of your meals on workdays and on days off.
A commute-driven 7 a.m. breakfast that becomes an 11 a.m. brunch, and a rushed 7 p.m. dinner that turns into a 10 p.m. one, add up to hours of drift that the body's internal clocks have to absorb.
The team drew on 104,806 adults in the NutriNet-Santé e-cohort, an ongoing French health study.
Participants completed 24-hour dietary recalls every six months across three non-consecutive days, one of them always a weekend.
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Researchers then compared eating patterns in the first two years with cardiovascular events during a median follow-up of 8.1 years.
Participants were sorted into three groups: those who kept meal times within an hour on the weekend (maintenance), those who ate more than an hour earlier (advance), and those who ate more than an hour later (delay).
The findings, and their limits
Compared with steady eaters, men in both the advance and delay groups had elevated risk.
Each extra hour of drift added roughly 14 percent to overall cardiovascular disease risk and about 21 percent to coronary heart disease risk.
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Associations persisted after accounting for diet quality, sleep duration, and social jetlag, the sleep-timing shift the study is named after.
No significant association appeared in women, and none for cerebrovascular disease in either sex.
The researchers note the sex difference may partly reflect the higher absolute rate of cardiovascular events in men in the cohort.
This is observational research, which can flag a pattern but cannot prove that irregular meal times cause heart disease.
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It builds on an earlier NutriNet-Santé analysis from December 2023 linking a later first meal to higher cardiovascular risk.
What it might mean for your week
The mechanism the authors point to is chronobiological.
Meals are one of the strongest cues the body uses to keep peripheral clocks in the liver, gut and cardiovascular tissue synchronized with the master clock in the brain.
Shifting eating times across the week may mean those clocks are pulled out of alignment every few days.
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According to Bernard Srour, research director at INRAE, the regularity of meal times between weekdays and the weekend may matter as much as not eating late, and the effect appears to hold independently of how long people sleep.
If your weekday breakfast becomes a late Saturday brunch and dinner slides to 10 p.m., keeping the midpoint of your meals within about an hour of your weekday schedule is the pattern linked to lower risk in the study.
Anyone with existing heart-disease risk factors should discuss meal timing changes with their doctor.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.