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

• We estimated sleep duration using accelerometry in Mexican American 8–10-year-olds.
• Most children were short sleepers (<10 h).
• We examined sleep duration at baseline on obesity risk at the 24-month follow-up.
• Shorter sleep duration was associated with increased weight status among Mexican American children at the 24-month follow-up.
• Sleep duration may be a primary target for addressing obesity in this population.

ObjectiveCross-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 methodsWe 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.ResultsChildren 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.ConclusionIn Mexican American children, shorter sleep duration at baseline was associated with increased weight status over 24 months.