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A new study looks at meal timing and cardiovascular risk. Maskot/Getty Images
  • People who ate their first and last meals earlier in the day had a lower risk of cardiovascular disease than those who ate later in the day.
  • In addition, a longer overnight fasting period was linked to a lower risk of stroke and other cerebrovascular conditions.
  • More research is needed before doctors can recommend that people shift their meal times.

Which foods you eat can increase or lower your risk of heart attack, stroke, and other types of cardiovascular disease. But more research is finding that what time you eat your meals may also matter.

Adding to this, a new study published Dec. 14 in Nature Communications found that having later times for the first and last meals of the day was linked to a higher overall risk of cardiovascular diseases. This effect was stronger in women than men.

“There is a growing body of literature showing that eating earlier in the morning and in the evening — earlier breakfast times and earlier dinner times — is beneficial, in terms of metabolism,” said Pamela Martyn-Nemeth, PhD, RN, a professor in the Department of Biobehavioral Nursing Science at the University of Illinois Chicago.

“There has also been some investigation about time-restricted eating, which is a little bit different than meal timing, but is related,” she told Healthline.

Martyn-Nemeth was not involved in the new research.

In the study, researchers looked at the link between when people ate their meals throughout the day and their risk of cardiovascular disease.

The research included 103,389 adults participating in the NutriNet-Santé study, an ongoing web-based study in France that looks at the link between nutrition and health.

The mean age of participants was around 42 years old, and almost 8 out of 10 were women.

Researchers used dietary records submitted online by participants to estimate when and how often people ate during the day. They followed participants for an average of around 7 years.

They found that in the morning, “each additional hour in delaying the time of first meal of the day was associated with a higher risk of overall [cardiovascular disease.]”

The researchers also found that “each additional hour in delaying the time of last meal was associated with an 8% increased risk of cerebrovascular disease.”

They found people eating their last meal after 9 pm had a 28% higher risk of cerebrovascular disease compared to people who ate their last meal before 8 pm.

These effects for both of these were stronger in women than men.

In addition, longer nighttime fasting was linked to a lower risk of ischemic stroke and other types of cerebrovascular disease. However, overnight fasting time had no effect on overall risk of cardiovascular disease or coronary heart disease.

Also, how many times people ate during the day didn’t affect their cardiovascular risk.

“Our results suggest a potential benefit of adopting earlier eating timing patterns, and coupling a longer nighttime fasting period with an early last meal, rather than breakfast skipping, in [cardiovascular disease] prevention,” the researchers wrote in the paper.

Although Martyn-Nemeth said more research is needed, she pointed out that the study had several strengths, such as the large number of participants, the extended follow-up, and that researchers took into account other variables that can affect cardiovascular risk.

However, there were some differences between earlier and later eaters that could have affected the results.

For example, younger people, those without a history of cardiovascular disease, current regular smokers, and people with higher physical activity levels tended to have later first and last meals.

In addition, participants who had later meals — compared to those with earlier meals — tended to consume more alcohol, binge drink more often, have later bedtimes, and eat meals at different times during the week.

One potential explanation for the lower cardiovascular risk with earlier meal times is the effects of meal timing on circadian rhythms in the organs.

Circadian rhythms are the roughly 24-hour cycles that form the body’s internal clock. One of the best-known of these is the sleep-wake cycle, which is tied to the cycle of day and night (aka light and dark).

Other environmental cues can also affect the circadian rhythms. Research shows that the daily eating and fasting cycle helps synchronize circadian rhythms in organs such as the liver, heart, kidney, and pancreas.

The authors of the new paper also suggest that some of the benefits may be due to longer overnight fasting. “We found an inverse association between nighttime fasting duration and the risk of cerebrovascular diseases,” they wrote.

Similar benefits of longer fasting periods have been seen in other research (although at least one study found no benefit).

For example, one study found that men with prediabetes who limited their eating to a 6-hour window — what’s known as time-restricted eating or intermittent fasting — had improvements in insulin sensitivity, blood pressure and appetite control.

Other research has found cardiovascular benefits or weight loss among people who did intermittent fasting.

Martyn-Nemeth said studies of intermittent fasting can be challenging, though, because people who have a shorter eating window sometimes end up eating fewer calories, which can also impact metabolism and cardiovascular risk.

Although she thinks the new study adds to our understanding of the impact of meal timing and overnight fasting duration on health, she said it’s too early to recommend that people eat their meals at a certain time of the day.

“We would need to take into account an individual person’s preferences, lifestyles, and health characteristics before we could make that type of recommendation,” she said.

In a large study with a 7-year follow-up, researchers found that people whose first and last meals were earlier had a lower risk of cardiovascular disease than those who ate later.

A longer overnight fasting period was also linked to a lower risk of stroke or other cerebrovascular disease, but the number of meals eaten during the day had no impact on this or overall cardiovascular disease.

A growing body of research suggests that eating first and last meals earlier and having a longer overnight fasting period, may be beneficial. Still, experts caution that more research is needed before making recommendations.