Blood Sugar & Your Internal Clock


You’ve heard it before, “Late dinners are bad for your health,” but do you actually know why? Recent research has strengthened the link between blood sugar and your internal clock, helping to explain why late dinners are potentially detrimental to your overall health.

A few definitions to consider first:

  • Glucose Tolerance: The ability to regulate blood-sugar levels 
  • Diabetes: A metabolic disease in which the body’s inability to produce any or enough insulin causes elevation levels of glucose in the blood

In a study led by researchers from Harvard-affiliated Brigham and Women’s Hospital (BWH), 14 healthy individuals were closely monitored with the ultimate goal of explaining why glucose tolerance is lower at dinner than at breakfast. Researchers measured the independent influences that behavioral factors (mealtimes, sleep), the body’s internal clock (circadian rhythm) and misalignment between these two components had on a person’s ability to control blood-sugar levels. To put things in real-world perspective, the team reported its findings with implications for shift workers and for the general public.

Frank Scheer of Harvard Medical School explains, “Our study underscores that it’s not just WHAT you eat but also WHEN you eat that greatly influences blood-sugar regulation, and that has important health consequences.”

The Study:

Participants took part in two protocols: The first, the participants had their first meal (breakfast) at 8am and their last meal (dinner) at 8pm. In the second, their schedules were reversed so breakfast was at 8pm and dinner at 8am. In this version, they were scheduled to sleep during the day. Researchers measured levels of glucose and insulin at 10-minute intervals after each meal and hourly throughout the full sleep/wake cycle.

The Results:

They found that glucose levels (lower glucose tolerance) were 17% higher in the evening than in the morning, independent of when a participant spelt or had their meals. They also found that simulated night work (sleeping during the day) lowered glucose tolerance throughout multiple days. The researchers believe that conflicting signals from the body’s internal clock may contribute to these effects of misalignment on glucose control.

The Next Step:

The goal with studies such as this is to develop and improve strategies for controlling glucose levels in day-active people and night workers. Scheer explains, “By better understanding the key factors that contribute to changes in glucose tolerance, we may be able to find better strategies to help mitigate the risk of diabetes for shift workers.

Ultimately, when food is consumed late at night, when our glucose tolerance is lower, the body is more likely to store those calories as fat rather than burn it as energy. Repeatedly eating late will ultimately lead to weight gain. Researchers are still reviewing WHY exactly there is a difference between how we process food in the morning and in the evening.

At Medical Metabolic Specialists, we take your lifestyle into consideration from the very beginning. We work with you to determine the best diet and exercise plan to help you achieve your goals. For more information or to get started on your weight-loss journey, contact us today!

Source: Harzard Gazette

Last updated on February 29, 2016, posted in: Healthy Tips, Recent research by
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