Department of Population and Health, Federal University of Rio Grande, Rio Grande, Brazil.
J Adolesc Health. 2012 Dec;51(6 Suppl):S16-21. doi: 10.1016/j.jadohealth.2012.06.025. Epub 2012 Nov 10.
To investigate screen-time change from early to mid adolescence, its predictors, and its influence on body fat, blood pressure, and leisure-time physical activity.
We used data from a longitudinal prospective study, conducted among participants of the 1993 Pelotas (Brazil) Birth Cohort Study. At baseline, adolescents were, on average, 11 years old. They were later visited at age 15 years. Screen time was self-reported, accounting for the time spent watching television, playing video games, and using the computer. Several predictors were examined. The effect of screen-time change on some health outcomes was also analyzed.
Screen time increased on average 60 min/d from 11 to 15 years of age, for the 4,218 adolescents studied. The groups that presented the highest increases in screen time were male, wealthiest, those whose mothers had higher education, and adolescents with a history of school failure. There were positive associations between screen-time change and body mass index, skinfold thickness, waist circumference, and leisure-time physical activity at 15 years of age.
Screen time increased from early to mid adolescence. This increment was higher among boys and the wealthiest adolescents. Increases in screen time affected body composition, with negative implications on adiposity.
调查青少年早期到中期的屏幕时间变化、其预测因素，以及其对体脂肪、血压和休闲时间体育活动的影响。
我们使用了来自巴西佩洛塔斯（Pelotas）1993 年出生队列研究的纵向前瞻性研究数据。在基线时，青少年的平均年龄为 11 岁。他们在 15 岁时接受了随访。屏幕时间是通过自我报告来计算的，包括看电视、玩电子游戏和使用电脑的时间。我们检查了几个预测因素。还分析了屏幕时间变化对某些健康结果的影响。
在 4218 名研究的青少年中，屏幕时间平均每天增加了 60 分钟，从 11 岁到 15 岁。屏幕时间增加最多的群体是男性、最富裕的群体、母亲受教育程度较高的群体以及有学校失败史的青少年。屏幕时间变化与 15 岁时的体重指数、皮褶厚度、腰围和休闲时间体育活动呈正相关。
屏幕时间从青少年早期到中期增加。男孩和最富裕的青少年中增加的幅度更高。屏幕时间的增加会影响身体成分，对肥胖产生负面影响。
