What did the research discover?
This study looked at how a person’s chronotype—whether they are a “morning person” or “night owl”—affects their risk of developing type 2 diabetes and whether lifestyle choices play a role. Researchers followed 63,676 middle-aged nurses who had no history of diabetes, cancer, or heart disease from 2009 to 2017. They divided participants into three groups: morning chronotype, intermediate chronotype, and evening chronotype based on self-reported sleep habits.
The study found that people with an evening chronotype (night owls) were more likely to have unhealthy lifestyle habits, such as poor diet, less exercise, smoking, and shorter sleep. Over 469,120 person-years of follow-up, 1,925 cases of diabetes were reported.
Compared to morning types, the risk of developing diabetes was:
- 21% higher for intermediate types.
- 72% higher for evening types.
However, when the researchers adjusted for lifestyle factors like body mass index (BMI), physical activity, and diet, the increased diabetes risk for evening types was reduced but still remained significant. This suggests that both lifestyle choices and chronotype itself may contribute to diabetes risk.
How can I apply this information?
This study suggests that being a night owl may increase your risk of diabetes, but healthy lifestyle choices can help reduce that risk. People who prefer staying up late tend to have poorer sleep schedules, unhealthy diets, and less physical activity, which may explain their higher chance of developing diabetes.
If you identify as an evening chronotype, you can lower your diabetes risk by:
- Maintaining a balanced diet with plenty of whole foods.
- Exercising regularly, even if it means adjusting your routine to fit your natural rhythm.
- Prioritizing sleep and trying to maintain a consistent bedtime.
- Avoiding smoking and limiting alcohol consumption.
Because this study is research, more studies are needed to fully understand why evening chronotypes are more at risk for diabetes. However, the results highlight the importance of lifestyle modifications, especially for those who naturally prefer late-night schedules.
Source:
Kianersi S, Liu Y, Guasch-Ferré M, Redline S, Schernhammer E, Sun Q, Huang T. Chronotype, unhealthy lifestyle, and diabetes risk in middle-aged US women: a prospective cohort study. Annals of internal medicine. 2023 Oct;176(10):1330-9. https://pmc.ncbi.nlm.nih.gov/articles/PMC11196991/pdf/nihms-1999982.pdf
