# Does Bedtime Really Matter? Examining How Sleep Timing Relates to Sleep Duration and Overweight Status in Midwestern Latine Youth

## TL;DR

Earlier bedtimes and longer sleep are linked to lower overweight risk in Midwestern Latine youth, suggesting sleep timing is important for health.

## Contribution

This study highlights the unique role of sleep timing, not just duration, in reducing overweight risk among Latine youth.

## Key findings

- Youth who go to bed before 9:30 PM sleep longer and have lower overweight risk.
- Later bedtimes increase overweight risk, even when sleep duration is controlled.
- LL sleep patterns on weeknights are strongly associated with higher overweight risk.

## Abstract

Increased sleep duration, along with earlier bedtimes, seem to promote health by decreasing overweight risk in Midwestern Latine youth. Earlier bedtimes are associated with lowering the risk for being overweight, even when controlling for sleep duration.

What are the main findings?
Shortened sleep duration is related to increased risk of being overweight.Later bedtimes are related to risk of being overweight, even when factoring in sleep duration.

Shortened sleep duration is related to increased risk of being overweight.

Later bedtimes are related to risk of being overweight, even when factoring in sleep duration.

What are the implications of the main findings?
Interventions for preventing or intervening with overweight risk should consider sleep as a potentially important factor in determining health.Traditional studies have focused on sleep duration but sleep timing may play a unique and important role in decreasing overweight risk.

Interventions for preventing or intervening with overweight risk should consider sleep as a potentially important factor in determining health.

Traditional studies have focused on sleep duration but sleep timing may play a unique and important role in decreasing overweight risk.

Background/Objectives: Overweight and obesity is a continuing health concern for preadolescent youth. We assessed associations between sleep timing and sleep duration and body mass index/body composition in Latine youth. Methods: Participants were 119 Latine youth (mean age 11.53 year; 58.8% girls) and their mothers living in the rural Midwestern U.S. Youth reported their average bedtime and waking time. Heights and weights for children and mothers were measured by trained research assistants and were used to calculate BMI scores (in mothers), as well as BMI percentiles and overweight status (in youth). Mothers completed surveys for demographic variables. Results: Youth who went to bed before 9:30 PM (mean bedtime) obtained more sleep than those with later bedtimes (9.73 h vs. 8.63 h, respectively, t(117) = 7.88, p < 0.001). Each extra hour of sleep duration was associated with a decreased risk of being overweight (OR = 0.53 for weeknight sleep, OR = 0.67 for weekend night sleep), and each hour later to bed was related to increased risk for being overweight (OR = 2.35 on weeknights, and OR = 1.66 on weekend nights). To replicate previous work, we broke the youth up into four sleep timing groups: early-to-bed and early-to-rise (EE), early-to-bed and late-to-rise (EL), late-to-bed and early-to-rise (LE), and late-to-bed and late-to-rise (LL). Youth with LL sleep patterns on weeknights were much more likely to be overweight compared to youth with EE patterns (OR = 4.94). On weekend nights, compared to EE weekend youth, LE and LL weekend youth were more likely to be overweight (OR = 3.45 and OR = 3.32, respectively). Wake times were not significantly related to overweight risk. Conclusions: Sleep timing patterns, especially sleep duration and earlier bedtimes, may be important to address in future research on obesity interventions. Findings suggest that earlier bedtimes may play an important and complimentary role in health, in addition to sleep duration alone, and this study highlights the need for more research in underserved, minoritized populations.