Vezina–Im LA, et al. – This research was sought to clarify whether sleep duration was related to body mass index z scores (zBMI) and whether bedtimes or ethnicity was a moderator of the sleep duration–zBMI correlation among preschoolers from low–income families. The evidence showed that longer sleep duration was correlated with lower zBMI among low–income preschoolers when controlling for preschoolers' characteristics, but this was no longer the case when also controlling for parents' characteristics. Additional studies are required on the moderators of the sleep duration–zBMI correlation among low–income preschoolers.

Methods

• Researchers included 228 African American and Hispanic parents and their preschoolers from Head Start Centers.
• In this analysis, parents reported their preschoolers' sleep duration and bedtimes (using the Children's Sleep Habits Questionnaire) and their television watching.
• They measured food intake applying multiple days of digital photography to estimate energy intake at dinner.
• They applied Parenting Stress Index and the Center for Epidemiologic Studies Depression Scale to assess stress and depression.
• They further assessed parents' and preschoolers' height and weight by trained staff.

Results

• The data showed that longer sleep duration was significantly correlated with lower zBMI when controlling for demographics, bedtimes, energy intake at dinner, and television watching, but not when also controlling for parents' demographics, BMI, stress, and depression.
• It was indicated that preschoolers' sleep duration–zBMI association was not moderated by bedtimes or ethnicity.