Study Identifies 7h 19m as Optimal Sleep for Insulin Sensitivity

A new study of nearly 25,000 U.S. adults has identified 7 hours and 19 minutes as the optimal nightly sleep duration for minimizing insulin resistance, a key risk factor for type 2 diabetes. Researchers found that deviations in either direction—too little or too much sleep—were associated with poorer metabolic health, while moderate weekend catch-up sleep offered benefits only for those short on weekday rest.

The research, led by scientists at Nantong University in China, analyzed self-reported sleep data from the National Health and Nutrition Examination Survey spanning 2009 to 2023. Participants, aged 20 to 80, provided details on weekday and weekend sleep habits, alongside measurements used to calculate estimated glucose disposal rate, or eGDR—a validated indicator of insulin sensitivity derived from waist circumference, blood pressure, and glycated hemoglobin levels. Higher eGDR scores signal better insulin response and lower diabetes risk.

Overall, the median weekday sleep was 7.5 hours, rising to 8 hours on weekends, with nearly half of respondents engaging in some catch-up sleep. The study revealed an inverted U-shaped relationship between weekday sleep and eGDR, peaking...