Night owls—those who are naturally active or awake late into the night—are nearly 50% more likely to develop type 2 diabetes (T2D) compared to early risers, according to a new study released on Monday. The research highlights that night owls tend to have higher body mass indexes (BMI), larger waistlines, and more hidden body fat, contributing to their increased diabetes risk.
Previous studies have shown that people with a late chronotype, or those who prefer staying up late and waking up late, are often more prone to unhealthy lifestyles and obesity. This new study confirms that night owls face a 46% higher risk of developing diabetes, suggesting that lifestyle alone doesn’t fully explain the increased risk.
Dr. Jeroen van der Velde, lead researcher from Leiden University Medical Centre in the Netherlands, explained that the circadian rhythm of night owls often misaligns with societal schedules, leading to circadian misalignment. This misalignment can cause metabolic disturbances, ultimately raising the risk of type 2 diabetes.
The study analyzed sleep timing, diabetes risk, and body fat distribution in over 5,000 participants, categorized into early chronotypes (20%), late chronotypes (20%), and intermediate chronotypes (60%). Researchers measured participants’ BMI, waist circumference, visceral fat, and liver fat, using advanced imaging techniques.
After a follow-up period of 6.6 years, around 225 participants were diagnosed with diabetes. Results indicated that late chronotypes had a BMI 0.7 kg/m² higher, a waist circumference 1.9 cm larger, 7 cm² more visceral fat, and 14% more liver fat compared to those with intermediate chronotypes.
The study’s findings suggest that excess visceral and liver fat play a significant role in increasing diabetes risk among night owls. These results will be presented at the Annual Meeting of the European Association for the Study of Diabetes (EASD) in Madrid, Spain, from September 9-13.
