Your weekend meal schedule may matter more than you think

By Dr. Sanchari Sinha Dutta, Ph.D.Reviewed by Lauren HardakerSep 2 2026

Researchers tracked weekday and weekend eating patterns in more than 100,000 adults to investigate whether seemingly small shifts in the daily eating window could matter for long-term cardiovascular health.

Image Credit: PattPaulStudio / Shutterstock 

Meal timing irregularities between weekdays and weekends were associated with a higher risk of cardiovascular disease in men, according to a new study published in the journal Communications Medicine.

Background

People living in modern industrialized societies often organize their weekday routines around work, educational, or household commitments, requiring them to adjust their meal and sleep times accordingly. However, during weekends, their routines may align more closely with their chronotype, which represents individual preferences for activity and rest schedules.

Such irregularity in sleep and meal timing between weekdays and weekends can disrupt the circadian system, the body’s 24-hour internal clock that regulates episodes of alertness and sleepiness in response to the environmental day-night cycle.

While the irregularity in sleep–wake timing between weekdays and weekends is termed social jetlag, eating jetlag refers to irregularity in meal timing. Social jetlag has been widely linked to cardiometabolic complications in adults. Studies investigating the impact of meal timing on cardiovascular health have indicated that having the first and last meals later in the day is associated with a higher risk of cardiovascular disease, while having the first meal later is associated with a higher risk of type 2 diabetes.

To address this gap, the current prospective observational study aimed to explore the relationship between eating jet lag and the risk of cardiovascular disease in a French cohort.

Study design

The researchers analyzed data from 104,806 participants in the ongoing NutriNet-santé e-cohort study, which began in 2009 to investigate the association between nutrition and health.

Dietary intake and meal timing data were collected from participants through a 24-hour dietary recall questionnaire for 3 non-consecutive days, including one weekend day. This was repeated every six months. Eating jetlag was calculated as the difference between weekday and weekend eating midpoints, defined as the first and last caloric intakes of the day, using records collected during the first two years of follow-up.

Participants whose eating midpoint differed by no more than one hour between weekdays and weekends were categorized as the 'maintenance' group. Participants who followed an eating midpoint more than 1 hour earlier on weekends than on weekdays were categorized as the 'advance' group. Participants who followed an eating midpoint more than 1 hour later on weekends than on weekdays were categorized as the 'delay' group.

Data on cardiovascular events were also collected from participants through a health questionnaire, which was further validated against their medical reports.

key findings

The study highlighted a significant association between jet lag intensity and increased risks of cardiovascular disease and coronary heart disease among male participants over a median follow-up of 8.1 years.

Specifically, eating jetlag showed significant associations with increased risks of cardiovascular disease and coronary heart disease among male participants in the advance group, as compared to maintenance group participants. In the delay group, only the risk of coronary heart disease was significantly higher. However, the association was more pronounced in the advance group. No association was observed with cerebrovascular disease.

The findings were similar after accounting for social jetlag and after excluding probable night-shift workers or unemployed participants.

Study significance

The study suggests that differences in meal timing between weekdays and weekends may be relevant to cardiovascular health, although the observational design cannot establish causality.

Compared to men who maintain a consistent eating time throughout the week, those who followed the advance eating schedule on weekends had a higher risk of cardiovascular disease and coronary heart disease, while those who delayed their weekend eating time had a higher risk of coronary heart disease. These associations were independent of diet quality and remained after accounting for bedtime, total sleep time, and social jetlag.

Social jetlag, an irregularity in sleep–wake timings between weekdays and weekends, has been widely linked to adverse cardiometabolic outcomes. Adjusting for social jetlag produced only minor changes in the associations observed in this study. Given these findings, the researchers highlight that investigating eating jetlag in large populations with a high exposure to social jetlag could offer insights into whether interventions targeting meal timing throughout the week might mitigate the negative health impacts of social jetlag.

Notably, significant associations were detected in men but not in women, although the formal test for a sex-by-sex interaction was not statistically significant. A higher absolute risk of cardiovascular events in men compared to women may partly explain these observations. The male-female differences in lifestyle habits and socio-professional activities may also contribute to the observed variations in risk estimates.

In a stratified analysis, associations were observed only among participants whose first meal occurred after the cohort median of 8:02 am. This finding, along with the overall findings, suggests that meal timing and regularity may be relevant to long-term cardiovascular risk, although intervention studies are needed to determine whether changing meal timing reduces risk.

One potential limitation of the study is the unavailability of data on participants’ actual work schedules. The researchers therefore assumed that Monday to Friday corresponded to weekdays and Saturday and Sunday corresponded to weekends. However, not all participants may have these work schedules, which could lead to an underestimation of the prevalence and intensity of eating jet lag in the study population.

The study analyses were adjusted for several lifestyle and sociodemographic confounding factors. However, residual confounding by other factors, such as work stress, recreational drug use, exposure to light at night, the timing of physical activity, and the timing of medication, cannot be entirely ruled out. The cohort was also 79% women and not representative of the French population, limiting the generalizability of the findings. Sleep data were available only for a subsample and were collected in 2014.