Research shows that men who eat at significantly different times on weekends compared to weekdays have a 14% higher risk of heart disease and 21% higher risk of heart attacks, according to a 2026 study of 104,806 French adults followed for over 8 years. This “eating jetlag” effect remained significant even after accounting for sleep and diet quality, suggesting meal timing consistency may independently protect heart health.
A major study of over 104,000 French adults found that people who eat at very different times on weekends compared to weekdays, a phenomenon called “eating jetlag”, may have a higher risk of heart disease. Researchers tracked participants’ meal times and eating patterns for over 8 years and discovered that men who shifted their eating schedules significantly between weekdays and weekends had increased cardiovascular problems. According to Gram Research analysis, this connection held true even after accounting for sleep duration and overall diet quality, suggesting that meal timing consistency matters for heart health.
Key Statistics
A 2026 cohort study of 104,806 French adults found that men with eating jetlag, significant differences in meal timing between weekdays and weekends, had a 14% higher cardiovascular disease risk and 21% higher coronary heart disease risk over 8.1 years of follow-up.
Among men in the study, those who ate earlier on weekends compared to weekdays showed a 44% increased cardiovascular disease risk and 68% increased heart attack risk compared to those maintaining consistent meal times.
According to Gram Research analysis of this prospective cohort study, the association between eating jetlag and heart disease risk in men remained significant independently of sleep duration and diet quality, suggesting meal timing regularity is a distinct cardiovascular risk factor.
The study found that men who delayed their meals on weekends had a 36% higher coronary heart disease risk compared to those maintaining consistent eating schedules across the week.
The Quick Take
- What they studied: Whether eating at different times on weekends versus weekdays increases the risk of heart disease
- Who participated: 104,806 French adults (mostly women, average age 43) who reported their meal times repeatedly over 8+ years through a nutrition tracking study
- Key finding: Men who had significant eating jetlag showed a 14% higher risk of heart disease and 21% higher risk of heart attacks compared to those with consistent meal timing
- What it means for you: Keeping your meal times relatively consistent between weekdays and weekends may help protect your heart, especially if you’re male. However, this is one study and more research is needed before making major lifestyle changes
The Research Details
Researchers followed 104,806 people in France from 2009 to 2023, asking them to report what they ate and when they ate it multiple times throughout the study. On average, each person filled out detailed food diaries about 5.8 times. The researchers calculated “eating jetlag” by measuring the difference between when people ate their first meal and last meal on weekdays versus weekends, similar to how your body feels jet lag when traveling across time zones, but with meal timing instead.
The study tracked which participants developed heart disease over the 8+ year follow-up period. Researchers used statistical models to compare heart disease risk between people with high eating jetlag and those with consistent meal timing, while also accounting for other factors like how much people slept and the quality of their diet.
They also looked at three patterns: people who ate earlier on weekends (“Advance”), people who kept the same times (“Maintenance”), and people who ate later on weekends (“Delay”).
This research approach is important because it captures real-world eating patterns over many years rather than just looking at one moment in time. By following people and tracking what actually happened to their health, researchers can identify patterns that might increase disease risk. The study is particularly valuable because it measured eating jetlag objectively using actual meal times rather than asking people to remember their habits.
This is a large, well-designed study published in a reputable journal that followed people for over 8 years. The researchers validated heart disease cases by checking medical records, not just relying on what people reported. However, the study is observational, meaning it shows correlation but not definitive cause-and-effect. Most participants were women, so findings may not apply equally to men and women. The study was conducted in France, so results may differ in other countries with different eating cultures.
What the Results Show
Men who had eating jetlag showed a 14% higher risk of developing cardiovascular disease compared to those with consistent meal timing. The risk was even higher for heart attacks specifically, 21% higher, among men with eating jetlag. These associations remained significant even after researchers accounted for sleep duration and diet quality, suggesting that meal timing consistency matters independently of these other factors.
When researchers looked at the direction of eating jetlag, men who ate earlier on weekends (“Advance” group) had the highest risk, with a 44% increased cardiovascular disease risk and 68% increased heart attack risk. Men who ate later on weekends (“Delay” group) also showed increased heart attack risk at 36% higher than those maintaining consistent times.
Interestingly, the study found these associations primarily in male participants. Women in the study did not show the same increased cardiovascular risk associated with eating jetlag, though researchers note this may require further investigation.
The study found that eating jetlag intensity, how big the time difference was between weekday and weekend meals, mattered more than just having some variation. Larger discrepancies in meal timing were associated with greater cardiovascular risk. The findings held true across different age groups and remained significant after adjusting for multiple other health and lifestyle factors.
This research builds on earlier studies showing that disrupted circadian rhythms (your body’s internal 24-hour clock) can increase cardiometabolic problems. Previous research has linked irregular sleep schedules to heart disease risk. This study extends that concept to meal timing, suggesting that eating rhythm regularity is another important factor for heart health. The findings align with emerging research on how meal timing affects metabolism and cardiovascular function.
The study is observational, so it cannot prove that eating jetlag directly causes heart disease, only that they’re associated. Most participants were women, so results may not apply equally to men. People self-reported their heart disease cases initially, though researchers verified them with medical records. The study was conducted in France, so eating patterns and results may differ in other countries. Participants were generally health-conscious people tracking their diet, so results may not apply to the general population. The study cannot account for all possible factors that might influence heart disease risk.
The Bottom Line
If you’re male, try to keep your meal times relatively consistent between weekdays and weekends. Aim for eating your first meal and last meal at similar times throughout the week. This recommendation has moderate confidence based on this single large study; more research is needed for stronger conclusions. This should be considered alongside other proven heart disease prevention strategies like regular exercise, not smoking, managing stress, and eating a healthy diet.
This finding is most relevant to men concerned about heart disease prevention. People with irregular work schedules or shift work may find this particularly relevant. Women should note that this study didn’t find the same association in female participants, though maintaining regular meal times is still generally healthy. Anyone with existing heart disease or heart disease risk factors should discuss meal timing strategies with their doctor.
Heart disease develops over years, so the benefits of consistent meal timing would likely take months to years to manifest. This isn’t a quick fix but rather a long-term lifestyle adjustment that may contribute to cardiovascular health over time.
Frequently Asked Questions
Does eating at different times on weekends affect heart disease risk?
Research shows men with significant eating jetlag, large differences in meal timing between weekdays and weekends, have 14% higher heart disease risk and 21% higher heart attack risk. Women in the study showed no increased risk. More research is needed to confirm these findings.
How much does meal timing need to vary to increase heart disease risk?
The study measured eating jetlag as the difference between first and last meal times on weekdays versus weekends. Larger discrepancies showed greater risk, but the exact threshold wasn’t specified. Even moderate variations appeared to increase risk in men.
Is eating jetlag as important as diet quality and sleep for heart health?
The study found eating jetlag associated with heart disease risk independently of sleep duration and diet quality, suggesting it’s an additional factor to consider. However, all three, meal timing consistency, sleep, and diet quality, appear important for cardiovascular health.
What’s the best way to fix eating jetlag?
Keep meal times consistent between weekdays and weekends. Try eating your first and last meals at similar times throughout the week. The study didn’t test specific interventions, so this is a logical approach based on the findings.
Does this apply to women or just men?
This study found the eating jetlag-heart disease association primarily in men. Women participants didn’t show the same increased risk, though researchers note this requires further investigation. Women should still maintain healthy eating patterns.
Want to Apply This Research?
- Track your meal start and end times daily, comparing weekday versus weekend patterns. Set a goal to keep meal times within 1-2 hours of consistency across all days of the week.
- Set phone reminders for consistent meal times on weekends that match your weekday schedule. Start with just breakfast and dinner, gradually aligning weekend eating times to within 30 minutes of your weekday routine.
- Weekly review of meal timing consistency score. Calculate the average time difference between weekday and weekend meals. Track this metric monthly to identify patterns and celebrate improvements in consistency.
This research describes an association between eating jetlag and cardiovascular disease risk in men, but does not prove cause-and-effect. This study should not replace medical advice from your healthcare provider. If you have concerns about heart disease risk or are considering significant dietary changes, consult with a doctor or registered dietitian. The findings are based on a French population and may not apply universally. Individual results vary based on genetics, overall lifestyle, and other health factors.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
