Is it time for bed? Short sleep duration increases risk of obesity in Mexican American children.

OBJECTIVE: Cross-sectional studies show that sleep is related to childhood obesity. We aimed to examine the longitudinal impact of sleep on the risk of obesity in Mexican American children.

DESIGN AND METHODS: We evaluated 229 Mexican American 8-10-year-olds and their mothers at baseline and at 12- and 24-month follow-ups. Sleep duration and anthropometrics were collected. Age- and gender-specific body mass index (BMI) z-scores (BMIz) were calculated based on Centers for Disease Control and Prevention guidelines. Sleep duration was estimated using accelerometry. Children were also categorized as long or short sleepers, using the National Sleep Foundation's recommendation to define adequate sleep duration (10-11 h for 5-12-year-olds). Using linear regressions, we examined whether sleep duration predicted BMIz, waist-to-height ratio (WHtR), and weight gain at 24 months.

RESULTS: Children were mostly short sleepers (82%). Children who slept less were more likely to have a higher BMIz, WHtR, and weight gain at the 24-month follow-up (β = -0.07, P = 0.01; β = -0.11, P <0.01; and β = -0.14, P = 0.02, respectively), after controlling for baseline weight status, child gender, maternal BMI, and occupation.

CONCLUSION: In Mexican American children, shorter sleep duration at baseline was associated with increased weight status over 24 months.