To examine how clusters of energy balance-related behaviours (EBRBs), including sleep related factors, were associated with overweight among adolescents.
In Finland, 4262 adolescents, aged 13-15, participated in the cross-national Health Behaviour in School-aged Children study. The adolescents completed questionnaires assessing EBRBs [sleep duration, discrepancy and quality, physical activity (PA), screen time, junk food, fruit, and vegetable intake] and height and weight. Clusters were identified with ?-means cluster analysis and their associations with overweight with logistic regression analyses.
Common clusters for boys and girls were labelled "Healthy lifestyle" and "High screen time, unhealthy lifestyle". In addition, the cluster "Low/moderate screen time, unhealthy lifestyle" was identified among boys, and the cluster "Poor sleep, unhealthy lifestyle" among girls. Only girls in the cluster "High screen time, unhealthy lifestyle" were at increased risk for overweight.
Girls, whose EBRB was characterized by high screen time and low PA, but not with poor sleep, were at increased risk for overweight. Future studies should examine ways to promote PA among adolescent girls with high interest in screen-based activities.
This study investigated whether computer use is associated with health symptoms through sleep duration among 15-year olds in Finland, France and Denmark.
We used data from the WHO cross-national Health Behaviour in School-aged Children study collected in Finland, France and Denmark in 2010, including data on 5,402 adolescents (mean age 15.61 (SD 0.37), girls 53%). Symptoms assessed included feeling low, irritability/bad temper, nervousness, headache, stomachache, backache, and feeling dizzy. We used structural equation modeling to explore the mediating effect of sleep duration on the association between computer use and symptom load.
Adolescents slept approximately 8 h a night and computer use was approximately 2 h a day. Computer use was associated with shorter sleep duration and higher symptom load. Sleep duration partly mediated the association between computer use and symptom load, but the indirect effects of sleep duration were quite modest in all countries.
Sleep duration may be a potential underlying mechanism behind the association between computer use and health symptoms.
Electronic media use is becoming an increasingly important part of life for today's school-aged children. At the same time, concern of children's sleep habits has arisen, and cross-sectional studies have shown that electronic media use is associated with short sleep duration and sleep disturbances. The purpose of this longitudinal study was to investigate whether baseline electronic media use and media presence in a child's bedroom predicted sleep habits as well as changes in these sleep habits 18 months later among 10- to 11-year-old children in Finland.
The school-aged children (n=353, 51% girls) from 27 schools answered a questionnaire in 2006 and again 2008 in the Helsinki region of Finland. Electronic media use was measured by computer use and TV viewing. Media presence in a child's bedroom means the presence of a TV or a computer in a child's bedroom. Sleep habits were measured by bedtimes on school days and at the weekend days, sleep duration, discrepancy of bedtimes, and discrepancy of sleep duration between school days and weekends. Linear regression analyses were used to examine whether electronic media use and media presence predicted sleep habits with adjustments for grade, family structure, and baseline sleep. Gender differences were also examined.
The children used a computer for one hour per day and watched TV over one hour a day in 2006. They slept over nine hours on school days and over ten hours at the weekends in 2008. Computer use and television viewing predicted significantly shorter sleep duration (p