Josiane Broussard, PhD: Meal Timings Effect on Cardiometabolic Health, Sleep

If there was 1 thing to take away from the session “Meal Timing and Cardiometabolic Health: Consequences to Mechanisms” presented at SLEEP 2024, the 38th annual meeting of the Associated Professional Sleep Societies, it was that it is best to eat earlier in the day.¹

Much research has shown eating earlier in the day is linked to better health outcomes. Johns Hopkins University recommends keeping to roughly a 12-hour eating window, consuming a high-protein breakfast 30 minutes of waking up, eating lunch 4 hours after breakfast, eating dinner before 8 pm, eat snacks between meals, and eat meals every 3 – 4 hours.²

Josiane Broussard, PhD, from the Ludeman Family Center for Women’s Health Research at Colorado University Anschutz School of Medicine, presented the topic of meal timings’ effect on cardiometabolic health and the consequences, such as on sleep.¹

Broussard told HCPLive that studiesfound eating during the biological night which falls in the nighttime for diurnal animals like humans and the daytime for rodents, has negative impacts.

“We find that animals that eat during that time period have impaired cardiometabolic health outcomes [such as] higher risk for obesity, alterations in glucose, and insulin, things like that,” Broussard said.

Right now, little evidence exists on how meal timings interact with the circadian rhythm. However, research suggests meal timings may impact rhythms of peripheral tissues.

As for how meal timing influences hormonal regulation, Broussard said it depends on the hormone. For instance, meal timing would most likely not impact melatonin or the nighttime growth hormone. However, it may impact glucose since that is driven by meals.

Meal timing can also impact insulin sensitivity as people who eat later in the night are at risk for diabetes and obesity. These individuals tend to have lower insulin sensitivity.

Research showed time restricted eating reduces 24-hour glucose levels since it “squeezes into a smaller period of the day,” as Broussard explained.

Many dietary studies evaluated the potential benefits of restricting the food window to either the earlier or the later part of the day, but results were mixed. This could be because a lot of these studies failed to control for the food amount.

“So that's the question,” Broussard said. “As people say, time restricted eating might be beneficial, but it also might work through using that as a tool to reduce food intake.”

References

1. ^{Broussard, J, Grant, L, McHill, A. Meal Timing and Cardiometabolic Health: Consequences to Mechanisms. Session presented at SLEEP 2024. Houston, TX. June 1-5, 2024.}
2. ^{Nairn, R. Timing is Everything: Why Eating on a Regular Schedule Supports Overall Well-Being. Johns Hopkins University. December 9, 2024. https://wellbeing.jhu.edu/blog/2022/12/09/timing-is-everything-why-eating-on-a-regular-schedule-supports-overall-well-being/. Accessed June 7, 2024.}