This cross-sectional study aimed to investigate whether the combination of bedtime and screen time (ST) before bed were associated with obesity and diet quality in toddlers and school-aged children. Parents reported children's bedtimes and ST before bed (0 min, 1–30 min, >30 min). We then defined bed + screen time behavior using bedtime median cut-offs (early [EB] or late [LB]) and ST responses, resulting in four groups: EB–0′ST, EB ≤ 30′ST/LB–0′ST, EB > 30′ST/LB ≤ 30′ST, and LB > 30′ST. For all participants (n = 1133; 5.4 ± 2.7 years, 49.7% girls, 51.9% school-aged) we evaluated body mass index (BMI), diet quality, sleep-related variables, physical activity, and health-related quality of life (HRQoL). Outcome variables were compared across bed + screen time behavior groups, stratified by age group (toddlers and school-aged children) using general linear models for continuous variables, as well as chi-squared tests or logistic regressions for categorical variables. Additionally, we calculated linear p-trends. Analyses were adjusted for sociodemographic variables, BMI, and physical activity (unless the variable was tested). The results showed that toddlers and school-aged children in the LB ≥ 30′ST group were more likely to have overweight/obesity (OR: 3.42 [95%CI:1.41,8.26] and OR: 2.53 [95%CI:1.10,5.03], respectively) than those in the EB–0′ST group. Additionally, toddlers and school-aged children in the EB > 30′ST/LB ≤ 30′ST and LB > 30′ST groups showed significantly lower adherence to the Mediterranean diet compared to the other groups (p < 0.001). Regarding sleep-related outcomes, we observed that the combination of LB and more ST was associated with poorer sleep quality and shorter sleep duration in toddlers and school-aged children (p < 0.001). These findings emphasize the importance of promoting earlier bedtimes and limiting ST before bed as part of obesity prevention strategies for children. Furthermore, such intervention could benefit the quality of children's diet and overall lifestyle.

中文翻译：

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晚睡加上睡前更多的屏幕时间会增加西班牙儿童肥胖的风险并降低饮食质量

这项横断面研究旨在调查就寝时间和睡前屏幕时间 (ST) 的组合是否与幼儿和学龄儿童的肥胖和饮食质量相关。家长报告孩子的就寝时间和睡前 ST（0 分钟、1-30 分钟、>30 分钟）。然后，我们使用就寝时间中位数截止值（早期 [EB] 或晚期 [LB]）和 ST 反应来定义就寝 + 屏幕时间行为，从而分为四组：EB–0′ST、EB ≤ 30′ST/LB–0′ ST、EB > 30′ST/LB ≤ 30′ST，且 LB > 30′ST。对于所有参与者（n = 1133；5.4 ± 2.7 岁，49.7% 女孩，51.9% 学龄儿童），我们评估了体重指数 (BMI)、饮食质量、睡眠相关变量、体力活动和健康相关生活质量（HRQoL）。使用连续变量的一般线性模型以及分类变量的卡方检验或逻辑回归，比较了床+屏幕时间行为组的结果变量，按年龄组（幼儿和学龄儿童）分层。此外，我们还计算了线性 p 趋势。针对社会人口统计学变量、体重指数和体力活动对分析进行了调整（除非对变量进行了测试）。结果显示，LB≥30'ST组的幼儿和学龄儿童更容易超重/肥胖（OR：3.42 [95％CI：1.41，8.26]和OR：2.53 [95％CI：1.10， 5.03]，分别）高于 EB-0'ST 组。此外，与其他组相比，EB > 30'ST/LB ≤ 30'ST 和 LB > 30'ST 组的幼儿和学龄儿童对地中海饮食的依从性显着较低 (p < 0.001)。关于睡眠相关结果，我们观察到，LB 和更多 ST 的组合与幼儿和学龄儿童的睡眠质量较差和睡眠时间较短有关 (p < 0.001)。这些发现强调了促进早睡和限制睡前 ST 作为儿童肥胖预防策略的一部分的重要性。此外，这种干预可能有利于儿童饮食质量和整体生活方式。