The weekend can be different from weekdays in many ways – sleeping habits, work schedules, socializing – and a new study examines the possible health effects of changing eating habits on the weekend, described as “dietary jet lag.”
Published in Communication medicineThe study follows what we know about so-called social jet lag: Irregular sleep patterns, caused in part by differences in weekend routines, can be detrimental to health.
French and Spanish researchers analyzed data from 104,806 adults enrolled in an ongoing health study, comparing dietary habits with cardiovascular disease (CVD), over an average follow-up period of 8.1 years.
Although there was no clear correlation in the women’s data, among men, greater variation in meal times between the weekend and the rest of the week was associated with higher rates of heart disease — even after accounting for several other factors, including social jet lag.
“Our results suggest a role for weekend-weekday meal regularity in the etiology of cardiovascular disease, independent of sleep duration and diet quality, particularly in men,” the researchers write in their published article.
“If further studies confirm, meal regularity could be a strategy to mitigate the risk of cardiovascular disease.”
To measure meal times, the researchers found the average midpoint between when participants first ate or drank something on a weekday and when they last ate or drank something. The same was then done for weekends.
The greater the gap between the weekday and weekend midpoints, the greater the risk of cardiovascular disease. For men, an extra hour spent jet-lagged eating was associated with a 14% higher rate of cardiovascular disease overall and a 21% higher rate of coronary heart disease (including heart attacks) specifically.
))>Eating meals earlier on weekends was less common in the study cohort, but was associated with a higher level of risk.
“These associations are independent of diet quality and remain significant after adjusting for bedtime, total sleep duration, and social jet lag,” the researchers write.
The data collected here is not enough to prove direct cause and effect, as there may be other contributing factors that both increase the risk of cardiovascular disease and make jet lag-related dietary differences more likely.
Further research will be needed to identify the reasons for these associations, but the study team suggests that disruptions and irregularities in our natural biological clocks could place additional stress on the body, including the heart.
As for the absence of any association with women, researchers cite differences in hormones and metabolism as possible explanations. We also know that the risk of cardiovascular disease is higher in men.
“In many industrialized societies, irregular eating habits, such as skipping breakfast and eating late at night, are becoming more common,” the researchers write.
“Rest days (usually Saturday and Sunday) generally allow individuals to more closely align their sleeping and eating patterns with their body clock.
“This inconsistency in the timing of sleep and food intake can disrupt circadian rhythms – the internal clocks that coordinate homeostasis and metabolism and operate on (an) approximately 24-hour cycle (the circadian clock).”
We have several of these circadian clocks ticking within us, and studies have repeatedly shown that when our daily rhythms change — whether it’s sleeping, eating, or another habit — health complications can arise.
Next steps could involve looking at more diverse groups of people and a wider range of work habits – it was assumed for this study that all participants had Saturday and Sunday as their weekend – as well as testing how attempts to correct jet lag might improve heart health over time.
“If our findings are confirmed by further studies, meal timing and regularity could be an important focus of interventions aimed at reducing chronic disease risk and alleviating associated public health burdens,” the researchers write.
The research was published in Communication medicine.
This article was fact-checked by Rachel Garner and edited by Peter Dockrill. Although we are proud of our process, we are only human. If you spot an error, please let us know.
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