WHAT'S KNOWN ON THIS SUBJECT:Rates of screen media use have risen in parallel with rates of obesity among young people. Identifying the specific characteristics of media use that are associated with obesity can help elucidate the explanatory processes and inform effective interventions. WHAT THIS STUDY ADDS:This study examines the associations between BMI and characteristics of media use including the type of device, duration of use, and attention to the medium. The more that participants paid primary attention to television, the higher their BMI. abstract OBJECTIVES: This study investigates how characteristics of young adolescents' screen media use are associated with their BMI. By examining relationships between BMI and both time spent using each of 3 screen media and level of attention allocated to use, we sought to contribute to the understanding of mechanisms linking media use and obesity. METHODS:We measured heights and weights of 91 13-to 15-year-olds and calculated their BMIs. Over 1 week, participants completed a weekday and a Saturday 24-hour time-use diary in which they reported the amount of time they spent using TV, computers, and video games. Participants carried handheld computers and responded to 4 to 7 random signals per day by completing onscreen questionnaires reporting activities to which they were paying primary, secondary, and tertiary attention. RESULTS:Higher proportions of primary attention to TV were positively associated with higher BMI. The difference between 25th and 75th percentiles of attention to TV corresponded to an estimated +2.4 BMI points. Time spent watching television was unrelated to BMI. Neither duration of use nor extent of attention paid to video games or computers was associated with BMI.CONCLUSIONS: These findings support the notion that attention to TV is a key element of the increased obesity risk associated with TV viewing. Mechanisms may include the influence of TV commercials on preferences for energy-dense, nutritionally questionable foods and/or eating while distracted by TV. Interventions that interrupt these processes may be effective in decreasing obesity among screen media users. Pediatrics 2013;131:935-941

No abstract

Food insecurity has been associated with weight status in children and adults although results have been mixed. We aimed to identify whether food insecurity was associated with BMI in young adults and whether this association differed by gender and was modified by food stamp use and the presence of children in the home. Cross-sectional data from Wave 4 (2007–2008) of the National Longitudinal Study of Adolescent Health were analyzed. Multiple linear regression was used to investigate the association between food insecurity and BMI in gender stratified models of young adult women (n=7116) and men (n=6604) controlling for age, race/ethnicity, income, education, physical activity, smoking, alcohol use, the presence of children in the home, and food stamp use in young adulthood and/or adolescence. Food insecurity was more common in young adult women (14%) than young adult men (9%). After controlling for a variety of individual variables, food insecure women had a BMI that was on average 0.9kg/m2 units higher than women who were food secure. This difference in BMI persisted after controlling for recent or past food stamp use and was not different among women with or without children in the household. No relationship was found between food insecurity and BMI in young adult men. Providers should inquire about food insecurity, especially when treating obesity, and policy initiatives should address the role of access to healthy food in those facing food insecurity.

No abstract

This study used momentary sampling to characterize marijuana events among young frequent users and determine contextual and individual predictors of use severity. Medical clinic outpatients aged 15–24 who used marijuana at least twice a week completed a baseline assessment, then used a handheld computer to report marijuana use at 4–6 signal-prompted times per day and before/after use for two weeks. Reports assessed event characteristics (when, with whom, where, how, why, how much, how high). Timestamps identified time, weekend, and duration for each event. Generalized estimating equations tested associations of individual and event-specific contextual characteristics with hits/event, duration, and high. Forty-one youth completed 3868 momentary reports; 40 (98%) reported at least one marijuana use event (N=432 events; M=10.5/participant) and thus provided data for these analyses. Marijuana was most commonly used with other people (74% of events), at home (58%), via blunt (66%), and for social or enhancement reasons (86%). Most events (62%) occurred on weekdays; use was least likely in the morning (8%). Most events involved 6 or more hits (81%). Mean high was 5.2 (out of 8). Of events with start and end times (n=250), mean duration was 46.8 minutes. Poor mental health and use with a blunt or a bong, in the morning or evening, and on the weekend were associated with 6 or more hits/event. Female gender was associated with greater event duration. Poor mental health predicted higher high. Among youth who used frequently, marijuana was used in a variety of contexts, with diversity in method, dose, and duration. Contextual factors appeared to predict marijuana dose for a given event, while individual characteristics were more predictive of high and duration.