Examination of parent-reported differences in children's daily screen use, sleep, and sleep hygiene behaviors during the school year and summer and their association with BMI.

Objective: The current study examined school-summer differences in children's sleep patterns and sleep hygiene. Cross-sectional relationships with children's sleep, sleep hygiene, and weight status were explored during the school year and summer.

Methods: Children (5-8 years) and their parents (n = 197 dyads) were recruited from 4 schools in southeastern Texas and via Facebook. Parents reported children's school year and summer sleep, sleep hygiene, and screen media use. Children's body mass index (BMI) was objectively assessed at the beginning and end of the summer. Associations between children's sleep hygiene and screen media use, sleep duration, and weight status were explored.

Results: Children's sleep midpoint was earlier during the school year (1:54 AM ± 0.03) than in the summer (2:06 AM ± 0.03; t = 4.07, p < .0001). During summer, children increased their screen media use by 38 minutes (t = 2.32, p = .023) and decreased their caffeine intake from 7.43 to 7.0 (with scores ranging from 3 to 15; t = 2.83, p = .006). Greater sleep-inhibiting (β = 0.40, p = .011) and fewer sleep-promoting (β = -0.28, p = .049) behaviors during the school year were associated with having a higher BMI. There were no associations among sleep patterns, sleep hygiene and BMI during summer.

Conclusions: More positive school year sleep hygiene behaviors were supportive of having a healthier weight status. Changes in these behaviors during the summer did not portend worse weight outcomes. Supporting families in the establishment of sleep-promoting behaviors, particularly during the school year may help address the child obesity epidemic.