Marta Iraola Iribarren/Euronews
A new study suggests that eating at inconsistent times on weekends compared to weekdays could increase the risk of heart disease.
Do you eat breakfast at lunchtime and dinner at a time when you’d normally be sleeping during weekends? This inconsistency is what researchers call “eating jet lag” and it might be hurting men’s – you read it right, only men’s – hearts.
Early work or school starts often force people to adjust their eating schedules during the week, which differs from meal times on weekends and days off.
Such a shift in eating patterns may disrupt the body’s biological rhythms and could have implications for cardiovascular health, according to a new French study. Each additional hour of “eating jet lag” increased the risk of cardiovascular disease by 14% and the risk of coronary heart disease by 21% among men, researchers found.
“This study suggests the importance of regular meal-timing patterns, beyond sleep and diet quality, in cardiovascular disease prevention,” the authors wrote.
The research, published in Communications Medicine, analysed the timing of more than 100,000 participants’ first and last meals on working days and on weekends over a 14-year follow-up period between 2009 and 2023.
Men are more affected
Participants were classified by their eating schedules: the first group ate meals earlier on the weekends than during the week, the second group kept similar schedules across both and the last group had their meals later at weekends.
Both groups that ate either later or earlier than usual faced a higher cardiovascular risk than the regular group, regardless of overall diet quality.
Surprisingly, this pattern was only found among men, and women did not appear to be affected by schedule changes.
Why?
One reason could be that men generally have a higher absolute risk of cardiovascular disease. The authors also noted that women tend to be more inclined towards morning routines than men, a difference linked to variations in anatomy and hormones, which may influence how their bodies respond to shifts in meal timing.
What’s behind the irregular meal timings?
The authors’ leading theory for why this happens is that eating jet lag increases the risk of cardiovascular events through circadian disruption.
Circadian rhythms are the body’s internal clocks, running on a 24-hour cycle that help regulate its functioning. They are mainly regulated by light, but eating patterns can also act as a synchroniser for peripheral clocks, such as those in the liver and heart. Aligning eating patterns with these internal rhythms boosts metabolic health, while inconsistency can disrupt the body’s internal balance.
The authors noted that if the results are confirmed by further large-scale studies, meal timing regularity could become a key focus for interventions to reduce chronic disease risk and ease public health burdens.
