When Should You Eat?
Written by Sarena Yang
Edited by Chloe Chou
March 21, 2022
Edited by Chloe Chou
March 21, 2022
Some perks we are able to enjoy include receiving packages overnight, calling in an emergency late into the evening, or grabbing a snack to eat at a 24/7 convenience store. These luxuries are all made possible by night workers who begin their days as the rest of the world ends theirs. Unfortunately, because of the timing of their work, they are at higher risk of diabetes and other health conditions. Since this higher risk has not been explained by family history or socioeconomic status, researchers are turning to studying circadian rhythms, which are the body’s internal “clock” with a 24-hour rhythm that dictates sleeping, waking, eating, body temperature, and is largely regulated by factors such as light and dark (Circadian, 2021).
Researchers in the 2021 Chellappa et al. study isolated the effects of diets on circadian rhythms using a constant routine protocol to standardize behavior over a 14 day period. They studied three groups: day work control group, nighttime meal control group (NMC), and daytime meal intervention group (DMI). Night work groups had a sleeping cycle 12 hours out of sync with the day work control group. The NMC consumed meals both during the day and at night while the DMI consumed meals only during the day. The researchers monitored the participants’ glucose and insulin levels following meals (Chellappa et al., 2021).
Typically, glucose and insulin work together in the body to regulate blood sugar (CDC, 2021). Food is broken down into glucose, which is then taken up by one’s cells for energy with the help of insulin (CDC, 2021). With diabetes, not enough insulin is produced. Without enough insulin, high levels of glucose remain in the blood and can lead to health issues such as heart disease or kidney disease (CDC, 2021).
This study revealed that the NMC group showed a 19.4% increase in glucose and a 52.9% decrease in early-phase insulin after consumption of breakfast (Chellappa et al., 2021). This means that nighttime eating leads to a decrease in insulin activity, and cells will not be able to take up glucose for energy. In contrast, the DMI group showed no significant difference compared to the control group, indicating that eating during the daytime showed normal insulin activity and lower blood glucose (Chellappa et al., 2021).
These results indicate that eating at certain times can mitigate increases in blood glucose even with a misaligned circadian clock. In order to decrease the detrimental health effects night work has on the individual, it may be that eating meals during the daytime may be beneficial for night workers in lowering risk for diabetes.
References
CDC. (2021, December 16). What is Diabetes? Centers for Disease Control and Prevention. https://www.cdc.gov/diabetes/basics/diabetes.html
Chellappa, S. L., Qian, J., Vujovic, N., Morris, C. J., Nedeltcheva, A., Nguyen, H., Rahman, N., Heng, S. W., Kelly, L., Kerlin-Monteiro, K., Srivastav, S., Wang, W., Aeschbach, D., Czeisler, C. A., Shea, S. A., Adler, G. K., Garaulet, M., & Scheer, F. A. J. L. (2021). Daytime eating prevents internal circadian misalignment and glucose intolerance in night work. Science Advances. https://doi.org/10.1126/sciadv.abg9910
Circadian Rhythms and Circadian Clock | NIOSH | CDC. (2021, June 28). https://www.cdc.gov/niosh/emres/longhourstraining/clock.html
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