Accumulating evidence suggests that, independent of physical activity levels, sedentary behaviours are associated with increased risk of cardio-metabolic disease, all-cause mortality, and a variety of physiological and psychological problems. Therefore, the purpose of this systematic review is to determine the relationship between sedentary behaviour and health indicators in school-aged children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE and PsycINFO), personal libraries and government documents were searched for relevant studies examining time spent engaging in sedentary behaviours and six specific health indicators (body composition, fitness, metabolic syndrome and cardiovascular disease, self-esteem, pro-social behaviour and academic achievement). 232 studies including 983,840 participants met inclusion criteria and were included in the review. Television (TV) watching was the most common measure of sedentary behaviour and body composition was the most common outcome measure. Qualitative analysis of all studies revealed a dose-response relation between increased sedentary behaviour and unfavourable health outcomes. Watching TV for more than 2 hours per day was associated with unfavourable body composition, decreased fitness, lowered scores for self-esteem and pro-social behaviour and decreased academic achievement. Meta-analysis was completed for randomized controlled studies that aimed to reduce sedentary time and reported change in body mass index (BMI) as their primary outcome. In this regard, a meta-analysis revealed an overall significant effect of -0.81 (95% CI of -1.44 to -0.17, p = 0.01) indicating an overall decrease in mean BMI associated with the interventions. There is a large body of evidence from all study designs which suggests that decreasing any type of sedentary time is associated with lower health risk in youth aged 5-17 years. In particular, the evidence suggests that daily TV viewing in excess of 2 hours is associated with reduced physical and psychosocial health, and that lowering sedentary time leads to reductions in BMI.

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Systematic review of sedentary behaviour and health indicators in school-aged children and youth

OBJECTIVE: This paper explores the major changes in diet and physical activity patterns around the world and focuses on shifts in obesity DESIGN: Review of results focusing on large-scale surveys and nationally representative studies of diet, activity, and obesity among adults and children SUBJECTS: Youth and adults from a range of countries around the world MEASUREMENTS: The International Obesity Task Force guidelines for defining overweight and obesity are used for youth and the body mass index Z25 kg/m 2 and 30 cutoffs are used, respectively, for adults RESULTS: The nutrition transition patterns are examined from the time period termed the receding famine pattern to one dominated by nutrition-related noncommunicable diseases (NR-NCDs) The speed of dietary and activity pattern shifts is great, particularly in the developing world, resulting in major shifts in obesity on a worldwide basis Data limitations force us to examine data on obesity trends in adults to provide a broader sense of changes in obesity over time, and then to examine the relatively fewer studies on youth Specifically, this work provides a sense of change both in the United States, Europe, and the lower- and middle-income countries of Asia, Africa, the Middle East, and Latin America CONCLUSION: The paper shows that changes are occurring at great speed and at earlier stages of the economic and social development of each country The burden of obesity is shifting towards the poor International Journal of Obesity (2004) 28, S2–S9 doi:101038/sjijo0802804

https://cdr.lib.unc.edu/downloads/sb397b319

The nutrition transition: worldwide obesity dynamics and their determinants

Background: Epidemiologic data suggest an association between obesity and depression, but findings vary across studies and suggest a stronger relationship in women than men. Objective: To evaluate the relationship between obesity and a range of mood, anxiety, and substance use disorders in the US general population. Design: Cross-sectional epidemiologic survey. Setting: Nationally representative sample of US adults. Participants: A total of 9125 respondents who provided complete data on psychiatric disorder, height, and weight. Response rate was 70.9%. Main Outcome Measures: Participants completed an in-person interview, including assessment of a range of mental disorders (assessed using the World Health Organization Composite International Diagnostic Interview) and height and weight (by selfreport). Results:Obesity(definedasbodymassindex[calculated asweightinkilogramsdividedbythesquareofheightin meters]of30)wasassociatedwithsignificantincreases inlifetimediagnosisofmajordepression(oddsratio[OR], 1.21;95%confidenceinterval[CI],1.09-1.35),bipolardisorder (OR, 1.47; 95% CI, 1.12-1.93), and panic disorder oragoraphobia(OR,1.27;95%CI,1.01-1.60).Obesitywas associatedwithsignificantlylowerlifetimeriskofsubstance usedisorder(OR,0.78;95%CI,0.65-0.93).Subgroupanalysesfoundnodifferenceintheseassociationsbetweenmen andwomen,buttheassociationbetweenobesityandmood disorderwasstrongestinnon-Hispanicwhites(OR,1.38; 95%CI,1.20-1.59)andcollegegraduates(OR,1.44;95% CI, 1.14-1.81). Conclusions: Obesity is associated with an approximately 25% increase in odds of mood and anxiety disorders and an approximately 25% decrease in odds of substance use disorders. Variation across demographic groups suggests that social or cultural factors may moderate or mediate the association between obesity and mood disorder. Arch Gen Psychiatry. 2006;63:824-830

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Association Between Obesity and Psychiatric Disorders in the US Adult Population

Obesity is now reaching epidemic proportions in both developed and developing countries and is affecting not only adults but also children and adolescents. Over the last 20 years, obesity has become the most prevalent nutritional problem in the world, eclipsing undernutrition and infectious disease

https://www.cmaj.ca/content/cmaj/176/8/S1.full.pdf

2006 Canadian clinical practice guidelines on the management and prevention of obesity in adults and children [summary]

In order to more effectively promote fruit and vegetable intake among children and adolescents, insight into determinants of intake is necessary. We conducted a review of the literature for potential determinants of fruit and vegetable intake in children and adolescents. Papers were identified from Medline and PsycINFO by using all combinations of the search terms: "fruit(s) or vegetable(s)" and "children or adolescents". Quantitative research examining determinants of fruit and/or vegetable intake among children and adolescents aged 6–18 years were included. The selection and review process was conducted according to a four-step protocol resulting in information on country, population, design, methodology, theoretical basis, instrument used for measuring intake, statistical analysis, included independent variables, and effect sizes. Ninety-eight papers were included. A large number of potential determinants have been studied among children and adolescents. However, for many presumed determinants convincing evidence is lacking, mostly because of paucity of studies. The determinants best supported by evidence are: age, gender, socio-economic position, preferences, parental intake, and home availability/accessibility. Girls and younger children tend to have a higher or more frequent intake than boys and older children. Socio-economic position, preferences, parental intake, and home availability/accessibility are all consistently positively associated with intake. The determinants most consistently supported by evidence are gender, age, socio-economic position, preferences, parental intake and home availability/accessibility. There is a need for internationally comparative, longitudinal, theory-based and multi-level studies taking both personal and environmental factors into account. This paper is published as part of the special Pro Children series in the International Journal of Behavioral Nutrition and Physical Activity. Please see [
 http://www.ijbnp.org/content/3/1/26
 ] for the relevant editorial.

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Determinants of fruit and vegetable consumption among children and adolescents: a review of the literature. Part I: quantitative studies

Objective To describe the demographic characteristics of adolescent boys and girls who engage in three sedentary behaviors (television/video use, computer use, and reading/homework), and to explore how each sedentary activity is associated with body mass index (BMI), dietary behaviors, and leisure time physical activity. Design This study draws on data collected from Project EAT (Eating Among Teens), a school-based survey examining personal, behavioral, and socioenvironmental factors that are associated with nutritional intake among adolescents. Subjects The study sample consists of 4,746 middle and high school students from 31 public schools in a metropolitan area of the upper Midwest. All students were invited to participate. The overall response rate for Project EAT was 81.5%. Data collection was completed during the 1998-1999 school year. Statistical analyses Multivariate linear regression was used for examining associations between independent and dependent variables, controlling for age, race/ethnicity, and socioeconomic status. All differences were considered statistically significant at P Results Among boys, television/video use and time spent reading/doing homework were positively associated with BMI ( P P P P P Applications/Conclusions Messages and advice aimed at reducing time spent in sedentary activities should be targeted at television/video use instead of time spent reading, doing homework, or using a computer. Nutrition education should incorporate messages about the influence of the media and advertising on dietary behaviors.

Couch potatoes or french fries: are sedentary behaviors associated with body mass index, physical activity, and dietary behaviors among adolescents?

OBJECTIVE: To examine binge eating, depression, weight self-efficacy, and weight control success among obese individuals seeking treatment in a managed care organization. DESIGN: Gender-stratified analyses of associations between binge eating, depression, weight self-efficacy, and weight change, using data from a randomized clinical trial that compared low-cost telephone-based, mail-based, and usual care interventions for weight loss. SUBJECTS: A total of 1632 overweight individuals (460 men, 1172 women; mean age: 50.7 y; mean body mass index: 34.2 kg/m2) were recruited from a large Midwestern US managed care organization. MEASUREMENTS: Height and weight were measured by study personnel at baseline, and self-reported weight was assessed at 6 and 12 months; self-reported depression status, binge eating, and self-efficacy for weight control were assessed at baseline. RESULTS: Lifetime prevalence rates for depression and probable binge eating disorder were high. Weight self-efficacy was inversely related to weight in both men and women. For women, depression was associated with lower weight self-efficacy and higher body weight. Women reporting depression or lower weight self-efficacy at baseline had less weight loss success at 6 and 12 months. Depression, binge eating disorder, and weight self-efficacy were not significantly associated with weight loss success in men. CONCLUSION: Negative emotional states are highly prevalent and predict poor treatment outcomes, particularly for obese women. As obese women with clinical depression typically are excluded from intervention studies, further research on how to address the intersection of obesity intervention and mood management may be warranted.

Binge eating disorder, weight control self-efficacy, and depression in overweight men and women.

JEFFERY, ROBERT W. AND JENNIFER UTTER. The changing environment and population obesity in the United States. Obes Res. 2003;11:12S-22S. The recent unexpected increases in the prevalence of obesity in the United States are widely agreed to be the result of changes in environmental conditions. This paper reviews the available data from diverse sources on environmental factors and obesity. Coverage includes descriptive data on temporal trends in the environment, cross-sectional and longitudinal studies of the association between environmental exposures and body weight, and experimental trials that have related environmental factors thought to be potentially important in influencing energy intake and expenditure and body weight. Over the period covered by the “obesity epidemic,” a variety of environmental factors have changed dramatically. Some would seem to favor increased body weight (e.g., increased availability of convenience foods and increased use of automobiles and televised entertainment), and others would seem to favor decreased body weight (e.g., a lower-fat food supply and the increased availability of some forms of physical activity). Definitive conclusions about the relative contributions of energy intake and expenditure to increasing body weight or about the contribution of specific environmental exposures to increasing body weight are far from clear. Increased sophistication in methods for making valid inferences from existing environmental data would be helpful. Even more important, given the urgency of the problem, is experimental research on the question of what environmental changes would be necessary to reverse the obesity epidemic.

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The Changing Environment and Population Obesity in the United States

OBJECTIVE —This study examines the prevalence of specific weight control practices/disordered eating behaviors and associations with sociodemographic characteristics, BMI and weight perceptions, family functioning, and metabolic control among adolescent females and males with type 1 diabetes. RESEARCH DESIGN AND METHODS —The study population included 70 adolescent females and 73 adolescent males with type 1 diabetes who completed the AHEAD (Assessing Health and Eating among Adolescents with Diabetes) survey. Data on BMI and glycosylated hemoglobin (HbA 1c ) were drawn from medical records. RESULTS —Unhealthy weight control practices were reported by 37.9% of the females and by 15.9% of the males. Among the females, 10.3% reported skipping insulin and 7.4% reported taking less insulin to control their weight. Only one male reported doing either of these behaviors. Weight control/disordered eating behaviors were not associated with age, parental level of education, family structure, or race/ethnicity. Higher levels of weight dissatisfaction tended to be associated with unhealthy weight control/disordered eating; associations with BMI were inconsistent. Family cohesion was negatively associated with disordered eating among females ( r = −0.52; P r = −0.41; P 1c levels were significant among females ( r = 0.33; P r = 0.26; P CONCLUSIONS —Special attention is needed for youth with weight concerns and those from less cohesive families to assist in the development of healthy diabetes management behaviors.

https://care.diabetesjournals.org/content/diacare/25/8/1289.full.pdf

Weight Control Practices and Disordered Eating Behaviors Among Adolescent Females and Males With Type 1 Diabetes Associations with sociodemographics, weight concerns, familial factors, and metabolic outcomes

Jennifer Utter

Papers

Couch potatoes or french fries: are sedentary behaviors associated with body mass index, physical activity, and dietary behaviors among adolescents?

Binge eating disorder, weight control self-efficacy, and depression in overweight men and women.

The Changing Environment and Population Obesity in the United States

Weight Control Practices and Disordered Eating Behaviors Among Adolescent Females and Males With Type 1 Diabetes Associations with sociodemographics, weight concerns, familial factors, and metabolic outcomes

Reading magazine articles about dieting and associated weight control behaviors among adolescents.