It's not news that our bodies run on a 24-hour cycle—it's why we're usually awake when it's light out and asleep when it's not. But that's just one small part of how it all works. Now, research shows that the timing of our meals can also affect—and possibly delay—our body's internal clocks.
Yes, "clocks," as in plural. The master clock is located in the hypothalamus of our brain, but there are other peripheral clocks throughout the body based on things like metabolic rhythms and body temperature and they all essentially report back to that master clock. And the human body works best when all of these clocks are in sync with each other.
The study, published today in Current Biology, found that altered meal times can reset the clock in our metabolic tissue, and suggests that regular meal times might help keep all of the body's clocks on the same page.
Researchers from the University of Surrey followed ten healthy young men in a 13-day lab experiment as they ate three meals a day, each five hours apart. (All meals had the same amount of calories and same ratio of nutrients.) For the first few days, each participant had their first meal within 30 minutes of waking and then two more at five-hour intervals. Once participants were used to that schedule, all of their meal times were pushed back by five hours, and they stayed on the new schedule for six days.
After completing each meal schedule, the men underwent a 37-hour lab routine in order to measure their internal circadian rhythms, a delightful-sounding process including dim lighting, small hourly snacks, limited physical activity, and no sleep. Yes, the poor guys did this twice. The researchers found that delayed meals significantly affected the body's blood sugar rhythms, delaying them by five hours on average, and the rhythmic expression of a gene known as PER2, which is involved with a core clock component, was delayed by about an hour.
The findings suggest that for those with circadian rhythm disorders, like shift-workers, jet-laggers, or the average night owl, having regulated meal times, along with timed light exposure and melatonin supplements, can help reset the body's clock. For example, when traveling across time zones, people should adjust their meal times to their destination in order to lessen jet lag, according to Jonathan Johnston, a professor of chronobiology and integrative physiology, and an author on the study.
It should be noted, however, that delaying meals didn't seem to have an effect on sleepiness or hunger and it didn't change the brain's master clock, Johnston says; rather, timed meals are an extra element involved in syncing the body's internal rhythms.
Read This Next: Jet Lag Makes You Soft, Study of Baseball Players Suggests