To revise 1998 recommendations on childhood obesity, an Expert Committee, comprised of representatives from 15 professional organizations, appointed experienced scientists and clinicians to 3 writing groups to review the literature and recommend approaches to prevention, assessment, and treatment. Because effective strategies remain poorly defined, the writing groups used both available evidence and expert opinion to develop the recommendations. Primary care providers should universally assess children for obesity risk to improve early identification of elevated BMI, medical risks, and unhealthy eating and physical activity habits. Providers can provide obesity prevention messages for most children and suggest weight control interventions for those with excess weight. The writing groups also recommend changing office systems so that they support efforts to address the problem. BMI should be calculated and plotted at least annually, and the classification should be integrated with other information such as growth pattern, familial obesity, and medical risks to assess the child’s obesity risk. For prevention, the recommendations include both specific eating and physical activity behaviors, which are likely to promote maintenance of healthy weight, but also the use of patient-centered counseling techniques such as motivational interviewing, which helps families identify their own motivation for making change. For assessment, the recommendations include methods to screen for current medical conditions and for future risks, and methods to assess diet and physical activity behaviors. For treatment, the recommendations propose 4 stages of obesity care; the first is brief counseling that can be delivered in a health care office, and subsequent stages require more time and resources. The appropriateness of higher stages is influenced by a patient’s age and degree of excess weight. These recommendations recognize the importance of social and environmental change to reduce the obesity epidemic but also identify ways healthcare providers and health care systems can be part of broader efforts.

/pdf/expert-committee-recommendations-regarding-the-prevention-38kyxmdgpa.pdf

Expert Committee Recommendations Regarding the Prevention, Assessment, and Treatment of Child and Adolescent Overweight and Obesity: Summary Report

Background: The prominence of sedentary behavior research in health science has grown rapidly. With this growth there is increasing urgency for clear, common and accepted terminology and definitions. Such standardization is difficult to achieve, especially across multi-disciplinary researchers, practitioners, and industries. The Sedentary Behavior Research Network (SBRN) undertook a Terminology Consensus Project to address this need. Method: First, a literature review was completed to identify key terms in sedentary behavior research. These key terms were then reviewed and modified by a Steering Committee formed by SBRN. Next, SBRN members were invited to contribute to this project and interested participants reviewed and provided feedback on the proposed list of terms and draft definitions through an online survey. Finally, a conceptual model and consensus definitions (including caveats and examples for all age groups and functional abilities) were finalized based on the feedback received from the 87 SBRN member participants who responded to the original invitation and survey. Results: Consensus definitions for the terms physical inactivity, stationary behavior, sedentary behavior, standing, screen time, non-screen-based sedentary time, sitting, reclining, lying, sedentary behavior pattern, as well as how the terms bouts, breaks, and interruptions should be used in this context are provided. Conclusion: It is hoped that the definitions resulting from this comprehensive, transparent, and broad-based participatory process will result in standardized terminology that is widely supported and adopted, thereby advancing future research, interventions, policies, and practices related to sedentary behaviors.

/pdf/sedentary-behavior-research-network-sbrn-terminology-1kl8siwicz.pdf

Sedentary behavior research network (SBRN) - terminology consensus project process and outcome

There has recently been an increase in research related to the health impact of sedentary behaviour (e.g., sitting) (Tremblay et al. 2010). Numerous studies suggest that those who engage in high amounts of sedentary behaviour can be at increased risk of morbidity and mortality regardless of their level of moderateto vigorous-intensity physical activity (MVPA) (Dunstan et al. 2010; Grøntved and Hu 2011; Katzmarzyk et al. 2009; Thorp et al. 2011; Wijndaele et al. 2011). Further, it has been noted that there is often little association between sedentary behaviour and MVPA (Biddle et al. 2004; Ekelund et al. 2006) and that it is possible for an individual to accumulate large amounts of both MVPA and sedentary behaviour in the course of a day (Healy et al. 2008; Katzmarzyk et al. 2009; Owen et al. 2010; Tremblay et al. 2010; Wong and Leatherdale 2008). Taken together, these findings suggest that too much sitting and too little MVPA represent separate and distinct risk factors for chronic, noncommunicable diseases (e.g., cardiovascular disease, diabetes, cancer). While research into the biology and health impact of sedentary behaviour represents an exciting new field of study, current inconsistencies in terminology are confusing for students, researchers, policymakers, and the general public. In short, the term “sedentary” currently has two separate and contradictory operational definitions. In this emerging field of research, sedentary behaviours are typically defined by both low energy expenditure (e.g., resting metabolic rate, typically ≤1.5 metabolic equivalents (METs)) and a sitting or reclining posture (Owen et al. 2010; Pate et al. 2008; Tremblay et al. 2010). In this context, a person may be described as sedentary if they engage in a large amount of sedentary behaviour. In contrast, in the sport and exercise literature the term sedentary is frequently used to describe the absence of some threshold of MVPA (Church et al. 2009; Melanson et al. 2009; Mullen et al. 2011; Sims et al. 2012; Smith et al. 2010). Thus, it is common for researchers in this field to describe a participant as sedentary because they are not meeting physical activity guidelines. Hence, many exercise studies include a “sedentary control group” or refer to their participants as coming from a “sedentary population” because of their lack of physical activity without actually measuring or assessing their level of sedentary behaviour. It is not difficult to see how these conflicting definitions of the term sedentary can easily lead to confusion. When reading the title or abstract of an article, it is often difficult to ascertain which definition of sedentary the authors have employed. If an article focuses on the health impact of a “sedentary lifestyle”, are they concerned with excessive sitting–lying down, the lack of physical activity, or both? Further, it is surprisingly common for articles within a given academic journal to oscillate between one definition and the other. To prevent further confusion, we propose that journal editors adopt a consistent definition of the term sedentary and require that all manuscripts published within their journal adhere to this common terminology. We suggest that journals formally define sedentary behaviour as any waking behaviour characterized by an energy expenditure ≤1.5 METs while in a sitting or reclining posture. In contrast, we suggest that authors use the term “inactive” to describe those who are performing insufficient amounts of MVPA (i.e., not meeting specified physical activity guidelines). The formal adoption of the above definitions by journal editors and reviewers would greatly improve the clarity of research and discussion related to these important health behaviours and help researchers searching for studies specific to sedentary behaviour or physical inactivity. We hope the research community will support these definitions and we look forward to further improvements in our understanding of the health impacts of sedentary behaviour and physical activity.

Letter to the Editor: Standardized use of the terms "sedentary" and "sedentary behaviours"

Objective To synthesise reviews investigating physical activity and depression, anxiety, self-esteem and cognitive functioning in children and adolescents and to assess the association between sedentary behaviour and mental health by performing a brief review. Methods Searches were performed in 2010. Inclusion criteria specifi ed review articles reporting chronic physical activity and at least one mental health outcome that included depression, anxiety/stress, self-esteem and cognitive functioning in children or adolescents. Results Four review articles reported evidence concerning depression, four for anxiety, three for self-esteem and seven for cognitive functioning. Nine primary studies assessed associations between sedentary behaviour and mental health. Physical activity has potentially benefi cial effects for reduced depression, but the evidence base is limited. Intervention designs are low in quality, and many reviews include cross-sectional studies. Physical activity interventions have been shown to have a small benefi cial effect for reduced anxiety, but the evidence base is limited. Physical activity can lead to improvements in self-esteem, at least in the short term. However, there is a paucity of good quality research. Reviews on physical activity and cognitive functioning have provided evidence that routine physical activity can be associated with improved cognitive performance and academic achievement, but these associations are usually small and inconsistent. Primary studies showed consistent negative associations between mental health and sedentary behaviour. Conclusions Association between physical activity and mental health in young people is evident, but research designs are often weak and effects are small to moderate. Evidence shows small but consistent associations between sedentary screen time and poorer mental health.

/pdf/physical-activity-and-mental-health-in-children-and-1vtcx3fdp7.pdf

Physical activity and mental health in children and adolescents: a review of reviews

Sedentary behaviour is associated with deleterious health outcomes, which differ from those that can be attrib- uted to a lack of moderate to vigorous physical activity. This has led to the field of ''sedentary physiology'', which may be considered as separate and distinct from exercise physiology. This paper gives an overview of this emerging area of re- search and highlights the ways that it differs from traditional exercise physiology. Definitions of key terms associated with the field of sedentary physiology and a review of the self-report and objective methods for assessing sedentary behaviour are provided. Proposed mechanisms of sedentary physiology are examined, and how they differ from those linking physi- cal activity and health are highlighted. Evidence relating to associations of sedentary behaviours with major health out- comes and the population prevalence and correlates of sedentary behaviours are reviewed. Recommendations for future research are proposed.

/pdf/physiological-and-health-implications-of-a-sedentary-55lyzvdbza.pdf

Physiological and health implications of a sedentary lifestyle

OBJECTIVE: To review the empirical evidence of associations between television (TV) viewing, video/computer game use and (a) body fatness, and (b) physical activity. DESIGN: Meta-analysis. METHOD: Published English-language studies were located from computerized literature searches, bibliographies of primary studies and narrative reviews, and manual searches of personal archives. Included studies presented at least one empirical association between TV viewing, video/computer game use and body fatness or physical activity among samples of children and youth aged 3–18 y. MAIN OUTCOME MEASURE: The mean sample-weighted corrected effect size (Pearson r). RESULTS: Based on data from 52 independent samples, the mean sample-weighted effect size between TV viewing and body fatness was 0.066 (95% CI=0.056–0.078; total N=44 707). The sample-weighted fully corrected effect size was 0.084. Based on data from six independent samples, the mean sample-weighted effect size between video/computer game use and body fatness was 0.070 (95% CI=−0.048 to 0.188; total N=1722). The sample-weighted fully corrected effect size was 0.128. Based on data from 39 independent samples, the mean sample-weighted effect size between TV viewing and physical activity was −0.096 (95% CI=−0.080 to −0.112; total N=141 505). The sample-weighted fully corrected effect size was −0.129. Based on data from 10 independent samples, the mean sample-weighted effect size between video/computer game use and physical activity was −0.104 (95% CI=−0.080 to −0.128; total N=119 942). The sample-weighted fully corrected effect size was −0.141. CONCLUSION: A statistically significant relationship exists between TV viewing and body fatness among children and youth although it is likely to be too small to be of substantial clinical relevance. The relationship between TV viewing and physical activity is small but negative. The strength of these relationships remains virtually unchanged even after correcting for common sources of bias known to impact study outcomes. While the total amount of time per day engaged in sedentary behavior is inevitably prohibitive of physical activity, media-based inactivity may be unfairly implicated in recent epidemiologic trends of overweight and obesity among children and youth. Relationships between sedentary behavior and health are unlikely to be explained using single markers of inactivity, such as TV viewing or video/computer game use.

Relationships between media use, body fatness and physical activity in children and youth: A meta-analysis

There is growing concern over the effects of sedentary lifestyles on the health of young people Recent rapid increases in juvenile obesity have received a great deal of attention in the scientific and popular press and have been attributed partly to television viewing, computer games and other sedentary behaviours These are thought to compete with physical activity There is a 'moral panic' concerning the 'couch kids' culture in modern western society Project STIL (Sedentary Teenagers and Inactive Lifestyles) at Loughborough University is investigating 'what young people do' and focuses on active and inactive pursuits chosen in their leisure time The following issues are addressed in this paper with specific reference to young people: how do we define 'sedentary behaviour' and do key sedentary behaviours displace physical activity? Are key sedentary behaviours obesogenic? What are the secular trends for children and youth for TV viewing? Our results for young people suggest that: 1 TV viewing and video-game playing are largely uncorrelated with physical activity, suggesting that there is time for both 2 meta-analytic findings show that body fatness is not related in any clinically meaningful way with key sedentary behaviours 3 although more children and youth have greater access to TVs than in previous generations, the amount of TV watched per head has not changed for 40 years Preliminary findings from Project STIL suggest that inactivity is more complex that we sometimes think Indeed, measures of 'couch potato-ism', such as TV viewing, may be inappropriate markers of inactivity

http://journals.sagepub.com/doi/pdf/10.1177/146642400312400110

Physical activity and sedentary behaviours in youth: issues and controversies

Background: Assessing time spent in sedentary behaviours in relation to pubertal status, anthropometric differences, and body image will improve insight into the prevalence and determinants of such behaviours during adolescence. Aim: The study aimed to investigate the effects of age, puberty, gender, body composition, and sleep on sedentary behaviour. Participants and methods: Participants were 64 boys and 55 girls in Year 6 (10.0-10.9 years of age), Year 8 (12.0-12.9 years) and Year 10 (14.0-14.9 years). Body mass index and percentage body fat were calculated from anthropometric measures. Sedentary behaviour and sleep time were computed using momentary-time sampling. Body image was measured using the Children's Physical Self-Perception Profile. Pubertal status was assessed from self-report of secondary sexual characteristics. Results: After controlling for sleep time, no differences in sedentary time were seen for puberty onset or increased pubertal development. Correlations between pubertal status, body composition, and body image were stronger in girls than in boys. Correlations between body image and sedentary behaviour were not strong enough to infer behavioural choice differences. Conclusions: Reduced sleep time rather than changing body image and body composition during adolescence is associated with greater sedentary behaviour.

/pdf/pubertal-development-and-sedentary-behaviour-during-5cbo4sk1ok.pdf

Pubertal development and sedentary behaviour during adolescence

Hypothesis: Changes in body composition and body image during puberty will impact on sedentary behavioural choices.Aim: The study aimed to investigate the effects of changes in pubertal status, body composition and body image on changes in time spent being sedentary.Participants and methods: Eighty-three school students aged 10–15 years were studied at 6-month intervals. BMI and percentage body fat (%BF) were calculated from anthropometric measures. Sedentary behaviour and sleep time were computed for weekday and weekend days using momentary-time-sampling diaries. Body image was measured using the Physical Self-Perception Profile for Children. Pubertal status was assessed from self-reported secondary sexual characteristics.Results: During weekdays, boys’ sedentary behaviour increased by a significantly greater amount for those who increased pubertal level compared with those who did not. No significant correlations were found between changing pubertal status, body composition, and body image for either ge...

Ian Murdey

Papers

Relationships between media use, body fatness and physical activity in children and youth: A meta-analysis

Physical activity and sedentary behaviours in youth: issues and controversies

Pubertal development and sedentary behaviour during adolescence

Short-term changes in sedentary behaviour during adolescence: Project STIL (Sedentary Teenagers and Inactive Lifestyles)

Sedentary behaviors, body fatness and physical activity in youth: a meta-analysis