Multilevel predictors of adolescent physical activity: a longitudinal analysis

<p>Abstract</p> <p>Background</p> <p>To examine how factors from a social ecologic model predict physical activity (PA) among adolescents using a longitudinal analysis.</p> <p>Methods</p> <p>Participants in this longitudinal study were adolescents (ages 10-16 at baseline) and one parent enrolled in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA) and the Etiology of Childhood Obesity (ECHO). Both studies were designed to assess a socio-ecologic model of adolescent obesity risk. PA was collected using ActiGraph activity monitors at two time points 24 months apart. Other measures included objective height and weight, adolescent and parent questionnaires on multilevel psychological, behavioral and social determinants of PA, and a home PA equipment inventory. Analysis was conducted using SAS, including descriptive characteristics, bivariate and stepped multivariate mixed models, using baseline adjustment. Models were stratified by gender.</p> <p>Results</p> <p>There were 578 adolescents with complete data. Results suggest few statistically significant longitudinal associations with physical activity measured as minutes of MVPA or total counts from accelerometers. For boys, greater self-efficacy (B = 0.75, <it>p </it>= 0.01) and baseline MVPA (B = 0.55, <it>p </it>< 0.01) remained significantly associated with MVPA at follow-up. A similar pattern was observed for total counts. For girls, baseline MVPA (B = 0.58, <it>p </it>= 0.01) and barriers (B = -0.32, <it>p </it>= 0.05) significantly predicted MVPA at follow-up in the full model. The full multilevel model explained 30% of the variance in PA among boys and 24% among girls.</p> <p>Conclusions</p> <p>PA change in adolescents is a complex issue that is not easily understood. Our findings suggest early PA habits are the most important predictor of PA levels in adolescence. Intervention may be necessary prior to middle school to maintain PA through adolescence.</p

Adolescent physical activity and screen time: associations with the physical home environment

<p>Abstract</p> <p>Background</p> <p>Previous research on the environment and physical activity has mostly focused on macro-scale environments, such as the neighborhood environment. There has been a paucity of research on the role of micro-scale and proximal environments, such as that of the home which may be particularly relevant for younger adolescents who have more limited independence and mobility. The purpose of this study was to describe associations between the home environment and adolescent physical activity, sedentary time, and screen time.</p> <p>Methods</p> <p>A total of 613 parent-adolescent dyads were included in these analyses from two ongoing cohort studies. Parents completed a Physical Activity and Media Inventory (PAMI) of their home environment. Adolescent participants (49% male, 14.5 ± 1.8 years) self-reported their participation in screen time behaviors and wore an ActiGraph accelerometer for one week to assess active and sedentary time.</p> <p>Results</p> <p>After adjusting for possible confounders, physical activity equipment density in the home was positively associated with accelerometer-measured physical activity (p < 0.01) among both males and females. Most of the PAMI-derived measures of screen media equipment in the home were positively associated with adolescent female's screen time behavior (p ≤ 0.03). In addition, the ratio of activity to media equipment was positively associated with physical activity (p = 0.04) in both males and females and negatively associated with screen time behavior for females (p < 0.01).</p> <p>Conclusions</p> <p>The home environment was associated with physical activity and screen time behavior in adolescents and differential environmental effects for males and females were observed. Additional research is warranted to more comprehensively assess the home environment and to identify obesogenic typologies of families so that early identification of at-risk families can lead to more informed, targeted intervention efforts.</p

A School-Based, Peer Leadership Physical Activity Intervention for 6th Graders: Feasibility and Results of a Pilot Study

Background: The aim of this study was to promote physical activity in 6th graders by developing and testing the feasibility of an enhanced Presidential Active Lifestyle Award (PALA) program comprised of a peer leadership component and innovative exercise resource toolkit including DVDs. Methods: A racially/ethnically diverse sample of students received the standard PALA program (2 control schools, n = 61) or enhanced PALA+Peers program (2 intervention schools, n = 87) during 2006-2007 academic year. Results: Compared with the control condition, the intervention was successful in increasing moderate physical activity in all students (P = .02) and moderate and hard physical activity among girls (P = .03 and P = .04, respectively). Teachers and students reported a high level of satisfaction and receptivity with the intervention. All teachers thought the DVDs were well-received, and 87% of students reported that they would recommend the enhanced program to peers. Conclusion: Coupling peer leadership with DVDs that promote physical activity may be an effective way to increase youth physical activity

Weight and Weight-Related Behaviors Among 2-Year College Students

The purpose of this paper is to describe weight indicators and weight-related behaviors of students enrolled in 2-year colleges, including sex differences

Breakfast and fast food consumption are associated with selected biomarkers in adolescents

AbstractObjective: Skipping breakfast and consuming fast food are related to the risk of obesity and are common adolescent behaviors. The relationship between these behaviors and biomarkers related to diabetes and CVD is understudied in this population. Methods: Data are from a study of the etiologic factors related to obesity risk in adolescents. Breakfast and fast food consumption were assessed using a self-report survey. Anthropometrics, fasting lipids, glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were assessed. Multivariate analyses were used to examine the relationship between dietary behaviors and selected biomarkers, controlling for calories consumed, body mass index (BMI), and demographic covariates. Results: 367 adolescents (11 to 18-years; mean 14.7±1.8years) were assessed at the University of Minnesota-Twin Cities from 2006–2008. Breakfast consumption was significantly associated with lower BMI, body fat, insulin, HOMA-IR, and metabolic syndrome (MetS) cluster score, while fast food consumption was associated with higher BMI, body fat, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, HOMA-IR, and MetS cluster score. Some gender differences were observed. Conclusion: Breakfast and fast food consumption appear to be related to important metabolic syndrome biomarkers for chronic disease in a sample of healthy adolescents. The importance of this finding needs to be validated by examining the stability of this pattern over time and to assess the pattern in other populations

The Physical Activity Climate in Minnesota Middle and High Schools

Background—This article describes policies, practices, and facilities that form the physical activity climate in Minneapolis/St. Paul, Minnesota metro area middle and high schools and examines how the physical activity climate varies by school characteristics, including public/private, school location and grade level. Methods—Surveys examining school physical activity practices, policies and environment were administered to principals and physical education department heads from 115 middle and high schools participating in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA) study. Results—While some supportive practices were highly prevalent in the schools studied (such as prohibiting substitution of other classes for physical education); other practices were less common (such as providing opportunity for intramural (noncompetitive) sports). Public schools vs. private schools and schools with a larger school enrollment were more likely to have a school climate supportive of physical activity. Conclusions—Although schools reported elements of positive physical activity climates, discrepancies exist by school characteristics. Of note, public schools were more than twice as likely as private schools to have supportive physical activity environments. Establishing more consistent physical activity expectations and funding at the state and national level is necessary to increase regular school physical activity

Adolescent Physical Activity and the Built Environment: A Latent Class Analysis Approach

This study used latent class analysis to classify adolescent home neighborhoods (n=344) according to built environment characteristics, and tested how adolescent physical activity, sedentary behavior, and screen time differ by neighborhood type/class. Four distinct neighborhood classes emerged: (1) low-density retail/transit, low walkability index (WI), further from recreation; (2) high-density retail/transit, high WI, closer to recreation; (3) moderate–high-density retail/transit, moderate WI, further from recreation; and (4) moderate–low-density retail/transit, low WI, closer to recreation. We found no difference in adolescent activity by neighborhood class. These results highlight the difficulty of disentangling the potential effects of the built environment on adolescent physical activity