Sleeping approximately 7 hours and 18 minutes per night may represent the optimal duration for reducing the risk of insulin resistance, a precursor to type 2 diabetes, according to a large observational study published in BMJ Open Diabetes Research & Care. The research also suggests that weekend catch-up sleep may have mixed metabolic effects. While moderate recovery sleep may benefit individuals who are sleep-deprived during the week, regularly oversleeping and extending sleep by more than two hours on weekends may be associated with poorer glucose metabolism.
The study analysed data from 23,475 adults aged between 20 and 80 years who participated in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2023. Among them, 10,817 participants had complete information regarding weekend sleep duration. Researchers examined the association between weekday sleep duration and estimated glucose disposal rate (eGDR), a widely used surrogate marker for insulin resistance. Lower eGDR values below 6–7 mg/kg/min indicate a higher risk of insulin resistance, whereas higher values above 10 mg/kg/min suggest a lower risk.
Participants in the cohort had an average eGDR of 8.23 mg/kg/min. On weekdays, they reported sleeping an average of 7 hours and 30 minutes, while weekend sleep averaged about 8 hours. Nearly 48% of the participants reported engaging in some degree of weekend catch-up sleep, reflecting the common tendency to compensate for weekday sleep deficits.
The analysis demonstrated an inverted U-shaped relationship between sleep duration and eGDR. The optimal point appeared to be 7 hours and 18 minutes of sleep per night. When sleep duration was below this threshold, longer sleep was associated with improved eGDR values, suggesting a lower risk of insulin resistance. However, beyond this duration, additional sleep was linked to lower eGDR levels, indicating a potential increase in insulin resistance risk. This association appeared particularly evident among women and adults aged 40 to 59 years.
Weekend sleep patterns further influenced metabolic outcomes. Among individuals who slept less than the optimal duration during the week, extending sleep by one to two hours on weekends was associated with higher eGDR values compared with those who did not compensate with additional sleep. In contrast, among individuals already sleeping more than the optimal duration on weekdays, extending sleep by more than two hours during weekends was associated with lower eGDR levels, even after adjusting for factors such as lifestyle habits, ethnicity, marital status, and educational level.
The researchers note that the relationship between sleep and metabolic health may be bidirectional. Poor glycaemic status has previously been linked to both shorter and longer sleep durations, as well as to various sleep disturbances. This may create a vicious cycle in which metabolic dysfunction disrupts sleep patterns, and abnormal sleep patterns further worsen metabolic health. The researchers also acknowledge the potential for reverse causation, where impaired glucose metabolism may influence sleep behaviour rather than sleep directly affecting metabolic outcomes.
The findings suggest that sleep patterns, particularly the balance between weekday sleep and weekend recovery sleep, may play an important role in metabolic regulation. The results may help inform lifestyle guidance for individuals at risk of developing type 2 diabetes, highlighting the potential importance of maintaining consistent and moderate sleep durations rather than relying on excessive weekend catch-up sleep.
Reference
- Fan Z, Wei R, Chen T, Yan X, Yin S, Cao Y, et al. Association of weekday sleep duration and estimated glucose disposal rate: the role of weekend catch-up sleep. BMJ Open Diab Res Care. 2026 Mar 3;14(2). doi:10.1136/bmjdrc-2025-005692 PubMed PMID: 10.1136/bmjdrc-2025-005692.