Obesity among adolescents: sedentary leisure time and sleeping as determinants

Dynamic weight status changes and peer lifestyles in early adolescence: A social network analysis on a longitudinal cohort of Taiwanese youth

BACKGROUND

Friendship networks are relevant to adolescent weight status and lifestyle, but little is known about their relationship in an East Asian setting. Using a longitudinal cohort of Taiwanese adolescents, we studied how weight status and lifestyles might influence friendship. Simultaneously considering the influence of friendship networks, we further examined the effects of peers' lifestyles on the body weight status of adolescents.

METHODS

Data were retrieved from the first three waves of the Taiwan Youth Project (N = 2409; 51 % boys). Participants were asked to nominate their friends at school and to report their lifestyle factors (e.g. sleep habits, internet use, and athletic performance). Weight status was proxied by body mass index calculated from self-reported weight and height. Stochastic actor-based modeling was used for the friendship network analyses.

RESULTS

Considering network structure, adolescents selected friends based on similarities in weight status (β = 0.147 [standard error = 0.044], p < 0.001) and lifestyle factors, such as athletic performance (β = 0.181 [0.034], p < 0.001), internet use (β = 0.156 [0.039], p < 0.001), and social jetlag (β = 0.055 [ ± 0.022], p < 0.05). In the behavior dynamics model, we did not observe any peer influence on changes in adolescents' weight status.

CONCLUSION

These findings suggest a pervasive homophilic friendship selection explained by weight and lifestyle-based similarities, despite no evidence of peer influence on weight status. Stakeholders and care providers of adolescent health should be aware of the social network processes that underlie weight problems.

The association between sleeping behavior, obesity, psychological depression, and eating habits among adolescents in the emirate of Abu Dhabi–United Arab Emirates

Objective

The study aimed to investigate the association between sleeping behavior (specifically sleep duration), body mass index (BMI), eating habits, and psychological mood depression among adolescents in the Emirate of Abu Dhabi- UAE.

Methods and materials

A subsample of three hundred and ninety-five participants (209 females and 186 males) from middle and high schools (aged 12–18 years) in the emirate of Abu Dhabi completed the surveys in the presence of their parents and two research assistants. Measures of daytime sleepiness and other sleep parameters (sleep duration on weekdays and weekends), eating habits, and mood depression questionnaires were reported.

Results

Differences in BMI between males and females were statistically significant (26.12 ± 4.5 vs. 24.4 ± 4.3; p < 0.01). There was a negative linear association (p < 0.01) between the students’ BMI and the weekday/ weekend sleep duration. The average weekday and weekend sleep duration ranged from 5.7 hours (weekdays) to 9.3 hours(weekend). The study showed that an increase in BMI was correlated to mood depression (r = 0.396, p<0.01). In terms of eating habits, there was a significant association between eating unhealthy food and sleep duration; 72.6% of students who slept less than 6 hours reported unhealthy eating habits (p <0.05).

Conclusion

The study showed a clear association between short sleep duration and obesity among adolescents in the UAE. This relationship between sleep duration and obesity is less studied and less understandable. Future research about exploring how sleeping behaviors can affect obesity during adolescence can support understanding this association and create an effective intervention.

Overnutrition and Associated Factors Among High School Adolescents in Mid COVID-19 Pandemic in Ethiopia: Neglected Public Health Concern

BACKGROUND

Adolescent overnutrition is becoming a global public health problem, increasing at an alarming rate in developing countries. Overnutrition increases the risks of serious diet-related chronic diseases, including type 2 diabetes, hypertension, cardiovascular disease, and stroke. However, there is limited evidence on the magnitude and risk factors of overnutrition in the study area.

OBJECTIVE

To determine the magnitude of overnutrition and associated factors among school adolescents in Dire Dawa, Eastern Ethiopia.

METHODS

A cross-sectional study was conducted from May to June 2021 among 498 adolescent students selected using a multi-stage sampling procedure. A systematic random sampling technique was employed. Self-administered questionnaires, including food frequency and anthropometric measurement, were used to collect the data. The BMI-for-age Z score was calculated using the WHO Anthro-Plus. A binary logistic regression model was fitted with an odds ratio, and 95% confidence levels. Statistical significance is declared at a p-value below 0.05.

RESULTS

A total of 498 (98.4%) were included with the overall prevalence of overnutrition of 26.1% (95% CI: 22.3-29.9), where 23.7% and 2.4% had overweight and obesity, respectively. Being female (AOR = 3.32; 95% CI: 1.65-6.63), attending at private school (AOR = 4.97; 95% CI: 1.72-14.35), having sweet food preferences (AOR = 6.26; 95% CI: 3.14-12.5), snacking (AOR = 3.05; 95% CI: 1.11-8.36), sedentary behavior (AOR = 3.20; 95% CI: 1.67-6.09), and eating while watching TV (AOR= 2.95; 95% CI: 1.47-5.95) were significantly associated with overnutrition.

CONCLUSION

Overnutrition is a major emerging public health problem in eastern Ethiopia. School type, sex, sweet food preferences, habits of snacking, sedentary behaviors, and eating while watching TV were significantly associated with overnutrition. Therefore, public health strategies to curb overweight and obesity among high school adolescents are urgently needed in order to reduce the prevalence and its adverse complications.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

The Effect of Season and Neighbourhood-Built Environment on Home Area Sedentary Behaviour in 9-14 Year Old Children

There is little understanding of how the built environment shapes activity behaviours in children over different seasons. This study sought to establish how seasonal weather patterns, in a given year in a mid-western Canadian city, affect sedentary time (SED) in youth and how the relationship between season and SED are moderated by the built environment in their home neighbourhood. Families with children aged 9-14 years were recruited from the prairie city of Saskatoon, Canada. Location-specific, device-based SED was captured in children during three timeframes over a one-year period using GPS-paired accelerometers. Multilevel models are presented. Children accumulated significantly greater levels of SED in spring but significantly less SED in the fall months in comparison to the winter months. Children living in neighbourhoods with the highest density of destinations accumulated significantly less SED while in their home area in comparison to their counterparts, and this effect was more pronounced in the spring and summer months. On weekends, the rise in sedentariness within the home area was completely diminished in children living in neighbourhoods with the greatest number of destinations and highest activity friendliness. These results suggested that increasing neighbourhood amenities can lead to a reduced sedentariness of youth, though more so in the warmers months of the year.

Active Gaming Prevalence and Correlates by Type of Day in Spanish Youth

BACKGROUND

Active gaming has emerged as a new option to foster physical activity in youth. The aim of this study was to estimate the prevalence of active gaming in adolescents, to determine differences between active and nonactive gamers by type of day, and to examine predictors of being an active gamer.

METHODS

A cross-sectional study was conducted with 3095 Spanish adolescents aged 12 to 18 years who self-reported their involvement in moderate to vigorous physical activity, sedentary behaviors, and active gaming. Those engaging in active gaming for at least 10 minutes per day were considered active gamers. Student's 2-tailed t tests, chi-square test, and binomial logistic regression were performed.

RESULTS

About 25.9% of the adolescents were active gamers. They were younger, had higher body mass index, and spent more time on moderate to vigorous physical activity, television viewing, and sedentary video games with computer/console than nonactive gamers. There were more active gamers on weekends than on weekdays. On weekdays, more males than females were active gamers. Adolescents who did not meet sleep time guidelines were more likely to be active gamers on weekdays, whereas on weekends, being a girl, overweight/obese, and having a high socioeconomic status were predictors of being an active gamer.

CONCLUSION

Because active gaming may contribute to meeting physical activity guidelines, the present findings could enable better targeting of physical activity promotion programs.

A Nationwide Study of Myopia in Taiwanese School Children: Family, Activity, and School-Related Factors

The purpose of the study was to explore how fixed and modifiable family, activity, and school factors affect a student's myopia risk and severity. We used national cross-sectional data from Taiwanese children in Grades 4-6. Bivariate and multivariate analyses, including logistic and ordinary least squares regression, examined factors related to children's myopia status and severity. Age, parent myopia, and school district were associated with risk of myopia. One hour or more per day of near work (OR = 1.26) increased the odds of myopia. The same amount of time in outdoor activities (OR = 0.85) or moderate or vigorous physical activities (OR = 0.82) was associated with lower risk. Near work (β = 0.06), outdoor activity (β = -0.04), and outdoor recess (β = -0.03) predicted myopia severity. To promote healthy vision, nurses should advocate for and implement interventions that increase school children's time outdoors and in physical activities and reduce their time on near work.

Obstructive Sleep Apnea in Children and Adolescents and the Risk of Major Adverse Cardiovascular Events: A Nationwide Cohort Study in Taiwan

STUDY OBJECTIVES

This study has investigated the risk of major adverse cardiovascular events (MACEs), including acute myocardial infarction, coronary artery disease, peripheral artery disease, and acute stroke, among children and adolescents (age younger than 20 years) with obstructive sleep apnea (OSA).

METHODS

In this study, the population-based National Health Insurance Research Database of Taiwan was used to identify patients in whom OSA had been first diagnosed between 2000 and 2015. Children and adolescents with OSA (n = 6,535) were included with 1:3 ratio by age, sex, and index year of control participants without OSA (n = 19,605). The Cox proportional regression model was used to evaluate the risk of MACEs in this cohort study.

RESULTS

After a 15-year follow-up, the incidence rate of MACEs was higher in the OSA cohort when compared with the non-OSA control cohort (15.97 and 8.20 per 100,000 person-years, respectively). After adjusting for covariates, the risk of MACEs among children and adolescents with OSA was still significantly higher (hazard ratio = 2.050; 95% confidence interval = 1.312-3.107; P = .010). No MACEs were found in the children and adolescents with OSA who received continuous airway positive pressure treatment or pharyngeal surgery.

CONCLUSIONS

This study found a significantly higher risk of MACEs in children and adolescents with OSA. These findings strongly suggest that clinicians should provide careful follow-up and medical treatment for children and adolescents with OSA.

Prevalence of childhood and adolescent overweight and obesity in Asian countries: a systematic review and meta-analysis

INTRODUCTION

We conducted a systematic review and meta-analysis to estimate the prevalence of overweight and obesity in children (aged 5-12 years) and adolescents (aged 12-19 years) in Asian countries. Study design: Systematic review and meta-analysis.

MATERIAL AND METHODS

We comprehensively searched specialised databases for relevant studies conducted in Asian countries between January 1, 1999, and May 30, 2017. Random effects models (using the DerSimonian-Laird method) and generic inverse variance methods were used for quantitative data synthesis. Sensitivity analysis was conducted using the 'leave-one-out' method. Heterogeneity was quantitatively assessed using the I² index. Systematic review registration: CRD42016033061.

RESULTS

Among 22,286 identified citations, 41 studies met the inclusion criteria with n = 71,998 and n = 353,513 for children and adolescents. The pooled prevalence (overall, boys and girls) was 5.8% (n = 4175), 7.0% (n = 2631) and 4.8% (n = 1651) for obesity in children aged 5-11 years; 8.6% (n = 30,402), 10.1% (n = 17,990) and 6.2% (n = 10,874) for obesity in adolescents age 12-19 years. For overweight in children the values for overall, boys and girls were 11.2% (n = 7900), 11.7% (n = 4280) and 10.9% (n = 3698) respectively; and for overweight in adolescents, 14.6% (n = 46,886), 15.9% (27,183), and 13.7% (20,574). These findings were robust in sensitivity analyses. In children and adolescents a higher percentage of boys than girls are obese (children = 7.0 vs. 4.8%, adolescents = 10.1 vs. 6.2%, p < 0.001, respectively). Furthermore, in children and adolescents a higher percentage of boys than girls are overweight (children = 11.7 vs. 10.9%, adolescents = 15.9 vs. 13.7%, p < 0.001, respectively).

CONCLUSIONS

In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents is needed throughout Asian countries.

Relationships between adolescent body mass index, physical activity, and sensory-processing patterns: Relations entre l'indice de masse corporelle, l'activité physique et les schèmes d'intégration sensorielle des adolescents

BACKGROUND

Trends show a significant decline with adolescent physical activity (PA). Knowledge regarding how sensory-processing patterns and body mass index (BMI) relate to adolescents' PA participation is scarce.

PURPOSE

This study investigated if relationships exist between adolescent BMI, sensory processing, and PA participation.

METHOD

This correlational study collected data from 141 adolescents who completed the Adolescent/Adult Sensory Profile and the Physical Activity Questionnaire-Adolescent. Their BMIs were calculated using self-reported age, height, and weight. The data were analyzed using descriptive statistics and two-tailed Spearman's rank correlation coefficients.

FINDINGS

Adolescents with different sensory-processing patterns reported participation in both similar and distinct PAs. Participation in PA and BMI shared no significant correlation. Sensory sensitivity and BMI total ( r_s = -.171, p = .044) and BMI percentile ( r_s = -.191, p = .024) demonstrated significant correlations. Analysis revealed a correlation between sensory seeking patterns and PA ( r_s = .224, p = .008) as well as correlations among sensory quadrants and participation in specific PAs.

IMPLICATIONS

Occupational therapists should consider an adolescent's sensory preferences when recommending PA interventions.

Fitness and food environments around junior high schools in Taiwan and their association with body composition: Gender differences for recreational, reading, food and beverage exposures

School environments may contribute to adolescent behavior, reproductive physiology and body composition (BC). The Nutritional and Health Survey in Taiwan (2010) for 1458 junior high school students was geo-mapped for 30 school environs. Facilities for physical activity (fitness centers, gymnasia and sports stadiums, activity centers and parks), sedentary activities (reading material rental shops (RMRS), internet cafes) and food and beverage outlets (FBOs) were calculated as weighted numbers within 1000m of schools. Multiple linear regressions were used to predict BC variable z-scores. For boys, higher fitness center densities and, for girls, gymnasia and sports stadiums were associated with less abdominal fatness. For girls, body mass index, waist circumference (WC) and triceps skinfold thickness (TSF) were greater when RMRS density was higher as was TSF with internet café density. Where there were no FBOs, boys’ WC and TSF were less with more parks, but girls were shorter and WC more adverse. With greater RMRS density and no FBOs, girls still had increased WC/Hip ratio, and less mid-arm muscle circumference. Boys’ findings were more evident after considering puberty. Physical activity facilities (differently by gender), food and beverage outlets absence for boys and low reading material rental shop density for girls increase the likelihood of healthier body composition.

Overweight and Obesity in Italian Adolescents: Examined Prevalence and Socio-Demographic Factors

AIM

This study aimed to evaluate the prevalence of overweight and obesity derived from measured data of weight and height in a cross-sectional sample of adolescents in the Italian region of Lazio and to analyse their association with different socio-demographic factors.

METHODS

The study was conducted in a representative sample of 15-16-year-old adolescents recruited in secondary schools between December 2011 and May 2012. 369 adolescents were investigated. Body weight, height and waist circumference were measured. The BMI of each subject was calculated, and the prevalence of overweight and obesity was determined by age and sex using the IOTF reference values and WHO growth standards. Waist circumference/height ratio (WC/Ht) was calculated and the subjects were classified using the cut-off of 0.5: WC/Ht≥0.5 and WC/Ht<0.5. Selected socio-demographic characteristics were assessed via questionnaire.

RESULTS

The percentages of overweight and obesity were high, 15.4% and 7.9%, respectively, with significant difference between males and females (19.1% vs. 12.6% for overweight and 11.1% vs. 5.3% for obese) using the IOFT reference. The ratio WC/Ht≥0.5 was observed in 12.7% of the sample (all the obese and 29.8% of the overweight subjects). Multiple logistic regression analysis indicated that gender, school municipality, mother's employment status, and family structure had a significant effect on ponderal status (overweight/obesity vs. normal weight).

CONCLUSION

These findings show a high prevalence of body weight excess associated with socio-demographic factors in the Italian sample investigated, and the need for effective public health interventions to combact obesity with particular attention to disadvantaged adolescents.

Influencing Factors of the Body Mass Index of Elementary Students in Southern Taiwan

The body mass index (BMI) of school children in Taiwan is markedly increasing. According to statistical data from the Taiwan Ministry of Education, the prevalence of obesity in school children from the southern part of the country is the highest in Taiwan. Thus, exploring the factors influencing BMI in elementary school children from southern Taiwan is crucial. This study investigated the influencing factors including physical activity levels, sedentary behaviors, dietary habits, and perceived body shape on the BMIs of elementary school children from southern Taiwan. A cross-sectional design was used, and the participants consisted of 3251 fifth-grade students (1628 boys, 50.1%; 1623 girls, 49.9%). The average BMI values for boys and girls were 19.69 and 18.70 (kg/cm) respectively. Statistically significant associations were observed between BMI and sex, 31–60 min of daily vigorous or moderate physical activities levels, length of time spent watching television, time spent on video games or the computer, and intake of vegetable or meat gravy with rice (p < 0.001). Perceived body shape also affected the BMI of school children. The results of this study enable educational institutions in Taiwan to understand the factors affecting the BMI of school children and use this information as the basis for future healthy body weight policies.

Systematic review of the relationships between sleep duration and health indicators in school-aged children and youth

The objective of this systematic review was to examine the relationships between objectively and subjectively measured sleep duration and various health indicators in children and youth aged 5-17 years. Online databases were searched in January 2015 with no date or study design limits. Included studies were peer-reviewed and met the a priori-determined population (apparently healthy children and youth aged 5-17 years), intervention/exposure/comparator (various sleep durations), and outcome (adiposity, emotional regulation, cognition/academic achievement, quality of life/well-being, harms/injuries, and cardiometabolic biomarkers) criteria. Because of high levels of heterogeneity across studies, narrative syntheses were employed. A total of 141 articles (110 unique samples), including 592 215 unique participants from 40 different countries, met inclusion criteria. Overall, longer sleep duration was associated with lower adiposity indicators, better emotional regulation, better academic achievement, and better quality of life/well-being. The evidence was mixed and/or limited for the association between sleep duration and cognition, harms/injuries, and cardiometabolic biomarkers. The quality of evidence ranged from very low to high across study designs and health indicators. In conclusion, we confirmed previous investigations showing that shorter sleep duration is associated with adverse physical and mental health outcomes. However, the available evidence relies heavily on cross-sectional studies using self-reported sleep. To better inform contemporary sleep recommendations, there is a need for sleep restriction/extension interventions that examine the changes in different outcome measures against various amounts of objectively measured sleep to have a better sense of dose-response relationships.

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

This systematic review is an update examining the relationships between objectively and subjectively measured sedentary behaviour and health indicators in children and youth aged 5–17 years. EMBASE, PsycINFO, and Medline were searched in December 2014, and date limits were imposed (≥February 2010). Included studies were peer-reviewed and met the a priori-determined population (apparently healthy children and youth, mean age: 5–17 years), intervention (durations, patterns, and types of sedentary behaviours), comparator (various durations, patterns, and types of sedentary behaviours), and outcome (critical: body composition, metabolic syndrome/cardiovascular disease risk factors, behavioural conduct/pro-social behaviour, academic achievement; important: fitness, self-esteem) study criteria. Quality of evidence by outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation framework. Due to heterogeneity, a narrative analysis was conducted. A total of 235 studies (194 unique samples) were included representing 1 657 064 unique participants from 71 different countries. Higher durations/frequencies of screen time and television (TV) viewing were associated with unfavourable body composition. Higher duration/frequency of TV viewing was also associated with higher clustered cardiometabolic risk scores. Higher durations of TV viewing and video game use were associated with unfavourable behavioural conduct/pro-social behaviour. Higher durations of reading and doing homework were associated with higher academic achievement. Higher duration of screen time was associated with lower fitness. Higher durations of screen time and computer use were associated with lower self-esteem. Evidence ranged from “very low” to “moderate” quality. Higher quality studies using reliable and valid sedentary behaviour measures should confirm this largely observational evidence.

Sleep Patterns and Academic Performance During Preparation for College Entrance Exam in Chinese Adolescents

BACKGROUND

Deficient sleep is linked to detrimental outcomes in health and school performance for adolescents. This study characterized sleep patterns in Chinese adolescents preparing for the College Entrance Exam (CEE) and evaluated the association between sleep patterns, self-rated academic performance, and the CEE scores.

METHODS

A sample of 481 Chinese adolescents in 12th grade (ages 16-19 years) completed questionnaires about sleep patterns, academic performance, academic stress, and sociodemographic factors 4-6 weeks before the CEE in June 2013. The CEE scores for each student also were obtained.

RESULTS

A total of 21% of the students had bedtimes after 12:00 am, 78.3% had sleep latency longer than 30 minutes, 14.6% had wake time earlier than 6:00 am, and the vast majority (94.4%) had sleep duration less than 8 hours. After adjusting for selected confounders such as academic stress, prolonged sleep latency was associated with poorer self-reported academic performance, and late bedtime was associated with higher CEE score.

CONCLUSIONS

Our findings highlight the complex association between sleep and academic performance. Assessing and monitoring sleep patterns in adolescents during periods of high academic demand and stress may yield important recommendations for their health and safety as well as establishing optimal sleep and study habits.

Short sleep duration as a risk factor for childhood overweight/obesity: a large multicentric epidemiologic study in China

OBJECTIVES AND SETTING

The present study was designed to examine the association of sleep duration with obesity/overweight in a multicentric urban sample of Chinese children.

PARTICIPANTS AND DESIGN

A random sample of 17,696 children aged 7.00-11.99 years participated in a cross-sectional multicentric survey.

MEASUREMENTS

The Chinese version of the Children's Sleep Habits Questionnaire was used to collect information on children's sleep behaviors. Body mass index (BMI) was calculated as weight (kilograms)/height squared (square meters). Sex, age, and BMI were used to define overweight and obesity based on the definition recommended by the Working Group on Obesity in China.

RESULTS

The prevalence of obesity and overweight in Chinese school-aged children was 10.7% and 10.3%, respectively. Hierarchical multiple linear regression models revealed a significant association between shorter sleep duration (hours/day) and increased BMI (β = -0.120; P = .019). Multivariate logistic regression models demonstrated that, compared with sleep duration ≥10 hours/d, mean sleep duration <9 hours/d experienced increased likelihood of overweight/obesity (odds ratio = 1.21; P = .005). Moreover, sleep-schedule variability, independent of sleep duration, was found to be associated with overweight/obesity (odds ratio = 1.11; P = .016).

CONCLUSIONS

Sleep duration and sleep-schedule variability, along with television viewing, homework schedule, and snack eating, were linked to overweight/obesity among elementary school children in this population-based sample.

Clinical Validation of the “Sedentary Lifestyle” Nursing Diagnosis in Secondary School Students

This study clinically validated the nursing diagnosis of “sedentary lifestyle” (SL) among 564 Brazilian adolescents. Measures of diagnostic accuracy were calculated for defining characteristics, and Mantel–Haenszel analysis was used to identify related factors. The measures of diagnostic accuracy showed that the following defining characteristics were statistically significant: “average daily physical activity less than recommended for gender and age,” “preference for activity low in physical activity,” “nonengagement in leisure time physical activities,” and “diminished respiratory capacity.” An SL showed statistically significant associations with the following related factors: insufficient motivation for physical activity; insufficient interest in physical activity; insufficient resources for physical activity; insufficient social support for physical activity; attitudes, beliefs, and health habits that hinder physical activity; and insufficient confidence for practicing physical exercises. The study highlighted the four defining characteristics and six related factors for making decisions related to SL among adolescents.

An integrative review of sleep interventions and related clinical implications for obesity treatment in children

PURPOSE

Evidence has shown correlations between obesity and sleep in children. The purpose of this review was to identify sleep interventions that could be utilized in primary care settings to prevent obesity in children.

RESULTS

Three themes emerged: bedtime routines and environment; parental presence and graduated extinction; and health education. Effective strategies to improve sleep in children include consistent bedtime routine and self-soothing.

CONCLUSION

Health care professionals can provide innovative and prevention-based sleep education for parents early in a child's development. Education, related to sleep, and appropriate sleep strategies may help prevent obesity and its long-term consequences.

Gender differences in home environments related to childhood obesity in Nanchang, China

BACKGROUND

Childhood obesity is rapidly increasing in China, with rates doubling between 2000 and 2010. Several large, epidemiological studies have shown boys to be consistently more likely to be obese than girls. The aim of this study was to investigate gender differences in the home environment and parenting practices related to childhood obesity.

METHODS

A cross-sectional survey using a convenience sampling of 522 (86.1% response rate) primary caregivers of children ages 2-10 years was conducted in four locations in Nanchang, China, in the spring of 2013 using face-to-face, anonymous questionnaires.

RESULTS

Boys were significantly (p<0.05) more likely than girls to watch more television (TV) per week, be allowed to have snacks/sweets or soft drinks without permission, and to have sugary drinks at snacks and meals. Girls were significantly more likely than boys to have parental encouragement and support for physical activity, participate in organized sports/group activities, and have fresh fruits accessible. Parents also believed that boys eat too much junk foods or their favorite foods if not controlled. Few differences were noted in the actual physical environment in the home, including access to sports equipment, junk food availability, and access to media.

CONCLUSIONS

RESULTS indicate that parents tend to be more permissive with boys than girls, allowing them access to unhealthy foods and more TV time. These differences may contribute to the higher prevalence of obesity in boys in China.

Insufficient sleep in adolescents and young adults: an update on causes and consequences

Chronic sleep loss and associated sleepiness and daytime impairments in adolescence are a serious threat to the academic success, health, and safety of our nation's youth and an important public health issue. Understanding the extent and potential short- and long-term repercussions of sleep restriction, as well as the unhealthy sleep practices and environmental factors that contribute to sleep loss in adolescents, is key in setting public policies to mitigate these effects and in counseling patients and families in the clinical setting. This report reviews the current literature on sleep patterns in adolescents, factors contributing to chronic sleep loss (ie, electronic media use, caffeine consumption), and health-related consequences, such as depression, increased obesity risk, and higher rates of drowsy driving accidents. The report also discusses the potential role of later school start times as a means of reducing adolescent sleepiness.

Pathway from central obesity to childhood asthma. Physical fitness and sedentary time are leading factors

RATIONALE

Available prospective studies of obesity and asthma have used only body mass index (BMI) as an indicator for adiposity; studies using detailed obesity measures are lacking, and the role of physical fitness level and sedentary time remains unexplored in the link between obesity and asthma.

OBJECTIVES

To compare various anthropometric measures of obesity in relation to childhood asthma, and to further characterize the interrelations among central obesity, physical fitness level, sedentary time, and asthma.

METHODS

The nationwide Taiwan Children Health Study followed 2,758 schoolchildren from fourth to sixth grade, annually collecting data regarding physical fitness, sedentary time, obesity measures (comprising body weight and height, abdominal and hip circumference, skin fold thickness, and body composition), asthma, and pulmonary function tests. The generalized estimating equation was used for 3 years of repeated measurements to analyze the interrelation among obesity, sedentary time, physical fitness level, and asthma; a structural equation model was used to explore the pathogenesis among these factors. Asthma incidence was analyzed during a 2-year follow-up among centrally obese and nonobese groups in baseline children without asthma.

MEASUREMENTS AND MAIN RESULTS

Central obesity most accurately predicts asthma. Low physical fitness levels and high screen time increase the risk of central obesity, which leads to asthma development. Obesity-related reduction in pulmonary function is a possible mechanism in the pathway from central obesity to asthma.

CONCLUSIONS

Central obesity measures should be incorporated in childhood asthma risk predictions. Children are encouraged to increase their physical fitness levels and reduce their sedentary time to prevent central obesity-related asthma.

Etiology of Obesity Over the Life Span: Ecological and Genetic Highlights from Asian Countries

Obesity is a worldwide pandemic, and the prevalence rate has doubled since the 1980s. Asian countries are also experiencing the global epidemic of obesity with its related health consequences. The prevalence of overweight and obesity are increasing at an alarming rate across all age groups in Asia. These increases are mainly attributed to rapid economic growth, which leads to socio-economic, nutrition and lifestyle transitions, resulting in a positive energy balance. In addition, fat mass and obesity-associated gene variants, copy number variants in chromosomes and epigenetic modifications have shown positive associations with the risk of obesity among Asians. In this review highlights of prevalence and related ecological and genetic factors that could influence the rapid rise in obesity among Asian populations are discussed.

Modelling the vicious circle between obesity and physical activity in children and adolescents using a bivariate probit model with endogenous regressors

The increasing prevalence of obesity in children and adolescents has become one of the most important public health issues around the world. Lack of physical activity is a risk factor for obesity, while being obese could reduce the likelihood of participating in physical activity. Failing to account for the endogeneity between obesity and physical activity would result in biased estimation. This study investigates the relationship between overweight and physical activity by taking endogeneity into consideration. It develops an endogenous bivariate probit model estimated by the maximum likelihood method. The data included 4008 boys and 4197 girls in the 5th-9th grades in Taiwan in 2007-2008. The relationship between overweight and physical activity is significantly negative in the endogenous model, but insignificant in the comparative exogenous model. This endogenous relationship presents a vicious circle in which lower levels of physical activity lead to overweight, while those who are already overweight engage in less physical activity. The results not only reveal the importance of endogenous treatment, but also demonstrate the robust negative relationship between these two factors. An emphasis should be put on overweight and obese children and adolescents in order to break the vicious circle. Promotion of physical activity by appropriate counselling programmes and peer support could be effective in reducing the prevalence of obesity in children and adolescents.

Functional consequences of inadequate sleep in adolescents: a systematic review

During adolescence, changes in sleep patterns due to biological and environmental factors are well documented. Later bedtimes and inadequate sleep, i.e., short and disrupted sleep patterns, insomnia and daytime sleepiness, have become increasingly common. Accumulating evidence suggests that sleep plays a crucial role in healthy adolescent development. This review systematically explores descriptive evidence, based on prospective and cross sectional investigations, indicating that inadequate sleep is associated with negative outcomes in several areas of health and functioning, including somatic and psychosocial health, school performance and risk taking behavior. Findings highlight the need for longitudinal investigations aimed at establishing the underpinnings of these associations and for developing and implementing interventions designed to achieve healthier and more balanced sleep patterns in the adolescent population.

Prevalences of overweight and obesity and their association with physical activity pattern among Iranian adolescents aged 12-17 years

OBJECTIVE

The objective of the present study was to investigate the prevalences of overweight and obesity and their association with physical activity pattern among adolescents in northern Iran.

DESIGN

A cross-sectional study.

SETTING

Babol, northern Iran.

SUBJECTS

A representative sample of 1200 adolescents aged 12-17 years was recruited. All selected adolescents were interviewed, their leisure-time and sport physical activities were collected by a standard Baecke questionnaire and their height and weight were measured by standard methods. The diagnosis of overweight and obesity was determined by comparing BMI values with the BMI index for age and sex percentiles set by the US Centers for Disease Control and Prevention in 2000.

RESULTS

The prevalences of overweight and obesity were 15.1 % and 8.3 %, respectively. The proportion of obesity was significantly higher in boys than in girls (10.2 % v. 6.5 %, P = 0.028). Overall, the levels of high, moderate and low leisure-time physical activity were 2.9 %, 79.4 % and 17.7 %, respectively. The corresponding levels of high, moderate and low sport physical activity were 17.4 %, 75.2 % and 7.4 %. The levels of leisure-time and sport physical activities were significantly higher among the boys than the girls (P < 0.001). There was also a significant association of studying in private schools and playing computer games with overweight/obesity (P < 0.001). Moderate leisure-time physical activity was unexpectedly associated with a greater risk of overweight/obesity compared with the low level (P = 0.002).

CONCLUSIONS

The findings indicate a high prevalence of overweight/obesity in these Iranian adolescents, particularly the boys. The influence of physical activity and diet on overweight/obesity requires further prospective studies.

The large sample size fallacy

BACKGROUND

Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article.

AIM

The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research.

RESULTS

Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself.

CONCLUSION

Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature.

Measuring and modelling body mass index among a cohort of urban children living with disadvantage

AIM

To report on baseline outcomes of body mass index, eating habits and physical activity of a cohort of urban disadvantaged children from a longitudinal evaluation of a school based, health promoting initiative.

BACKGROUND

The healthy schools programme was developed for implementation in schools located in disadvantaged areas of Dublin, Ireland.

DESIGN

A prospective, cohort study design was implemented.

METHOD

A 3-year longitudinal evaluation was conducted in five intervention and two comparison schools between 2009-2011. Data were collected on each participating child to determine their eating habits, levels of physical activity and body mass index at year 1 (baseline), year 2 and year 3. Independent t-tests were used to compare mean values, chi-square and Fishers exact tests were used to compare proportions at baseline.

RESULTS

Participation rates were over 50%. Older children reported eating on average more fruit and vegetables than younger children; breakfast was often eaten on the way to, or in school and in one age group 16.7% of intervention children reported they did not eat breakfast that day. Levels of physical activity varied with over 70% of younger children stating they never played a sport. In intervention schools over one quarter of all children were either overweight or obese. A comparison was conducted between the proportion of 9-year olds overweight and obese in our disadvantaged cohort and a national random sample of 8500 9-year olds and no important differences were observed.

CONCLUSION

Baseline results indicate that body mass index rates particularly among pre adolescent, urban disadvantaged girls are of concern.

Bariatric surgery: impact on body composition after Roux-en-Y gastric bypass

BACKGROUND

The aim of this study was to analyze the impact of bariatric surgery on the body composition of patients suffering from class III obesity at different postoperative time intervals.

METHODS

The body composition of 114 patients undergoing Roux-en-Y gastric bypass surgery was measured prior to surgery (T0) and then 30 (T30) and 180 (T180) days following surgery. Body composition was evaluated using the following parameters: total body mass, body mass index, excess weight, percentage of excess weight loss, relative body fat (%F), lean body mass (LBM), and fat tissue mass (FTM). To determine these variables, validated formulas and equations proper to obese men and women were employed.

RESULTS

A significant reduction in %F (41.5%), LBM (20.3%), FTM (37.9%) was noted at each time interval (p ≤ 0.01).

CONCLUSIONS

Bariatric surgery proved to be effective in reducing total body mass and body fat at every time interval. However, dietary measures emphasizing adequate protein intake may be implemented in order to reduce loss of LBM and, coupled with frequent physical activity, may help curtail the impact the surgery has on morphological variables.

Validation of a hip-worn accelerometer in measuring sleep time in children

This study compared measures of sleep from an accelerometer worn on the hip to measures obtained from an accelerometer worn on the wrist, the gold standard measure of sleep behavior in community research. The accelerometer worn on the hip provides a measure of total sleep time in 10- to 11-year-old children comparable to the wrist-worn unit. We provide an alternate method to ascertain bedtime and final wake time when diary data are missing. A hip-worn accelerometer may provide a cost-effective means of gathering physical activity and sleep data simultaneously in large samples of children with or without an accompanying sleep diary.

The relationship between obesity, insulin and arsenic methylation capability in Taiwan adolescents

PURPOSE

This study evaluated the arsenic methylation profile of adolescents and explored the influence of body mass index (BMI) on the arsenic methylation profile of adolescents in an area of Taiwan with no-obvious arsenic exposure.

METHODS

This study evaluated 202 normal weight students and 101 obese students from eight elementary schools, recruited from September 2009 to December 2009. Concentrations of urinary arsenic species, including inorganic arsenic, monomethylarsonic acid (MMA(5+)) and dimethylarsinic acid (DMA(5+)) were determined by a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry.

RESULTS

Urinary total arsenic was significantly decreased with increasing BMI, indicating that obese children may retain higher levels of arsenic in the body, as compared to normal weight children. Participants with obesity accompanied by high insulin levels had higher inorganic arsenic, significantly higher MMA percentage and significantly lower DMA percentage than those with obesity and low insulin levels. It seems children with obesity and high insulin levels had lower arsenic methylation capacity than those with obesity and low insulin.

CONCLUSIONS

This is the first study to demonstrate that total urinary arsenic is negatively associated with the BMI in adolescents in Taiwan, adjusted for age and sex. Obese adolescents with high insulin levels had significantly higher MMA% and significantly lower DMA% than obese adolescents with low insulin.

A systematic review of the validity and reliability of sedentary behaviour measures used with children and adolescents

The aim of this review was to evaluate the reliability and validity of methods used to assess the multiple components of sedentary behaviour (i.e. screen time, sitting, not moving and existing at low energy expenditure) in children and adolescents. Twenty-six studies met our inclusion criteria and were reviewed. Thirteen studies reported the reliability of self- and proxy-report measures of sedentary behaviour and seven of these were found to have acceptable test-retest reliability. Evidence for the criterion validity of self- and proxy-report measures was examined in three studies with mixed results. Seven studies examined the reliability and/or validity of direct observation and the findings were generally positive. Five studies demonstrated the utility of accelerometers to accurately classify sedentary behaviour. Self-report measures provide reliable estimates of screen time, yet their validity remains largely untested. While accelerometers can accurately classify participants' behaviour as sedentary, they do not provide information about type of sedentary behaviour or context. Studies utilizing measures of sedentary behaviour need to more adequately report on the validity and reliability of the measures used. We recommend the use of objective measures of sedentary behaviour such as accelerometers, in conjunction with subjective measures (e.g. self-report), to assess type and context of behaviour.

Secular trends: a ten-year comparison of the amount and type of physical activity and inactivity of random samples of adolescents in the Czech Republic

BACKGROUND

An optimal level of physical activity (PA) in adolescence influences the level of PA in adulthood. Although PA declines with age have been demonstrated repeatedly, few studies have been carried out on secular trends. The present study assessed levels, types and secular trends of PA and sedentary behaviour of a sample of adolescents in the Czech Republic.

METHODS

The study comprised two cross-sectional cohorts of adolescents ten years apart. The analysis compared data collected through a week-long monitoring of adolescents' PA in 1998-2000 and 2008-2010. Adolescents wore either Yamax SW-701 or Omron HJ-105 pedometer continuously for 7 days (at least 10 hours per day) excluding sleeping, hygiene and bathing. They also recorded their number of steps per day, the type and duration of PA and sedentary behaviour (in minutes) on record sheets. In total, 902 adolescents (410 boys; 492 girls) aged 14-18 were eligible for analysis.

RESULTS

Overweight and obesity in Czech adolescents participating in this study increased from 5.5% (older cohort, 1998-2000) to 10.4% (younger cohort, 2008-2010). There were no inter-cohort significant changes in the total amount of sedentary behaviour in boys. However in girls, on weekdays, there was a significant increase in the total duration of sedentary behaviour of the younger cohort (2008-2010) compared with the older one (1998-2000). Studying and screen time (television and computer) were among the main sedentary behaviours in Czech adolescents. The types of sedentary behaviour also changed: watching TV (1998-2000) was replaced by time spent on computers (2008-2010).The Czech health-related criterion (achieving 11,000 steps per day) decreased only in boys from 68% (1998-2000) to 55% (2008-2010). Across both genders, 55%-75% of Czech adolescents met the health-related criterion of recommended steps per day, however less participants in the younger cohort (2008-2010) met this criterion than in the older cohort (1998-2000) ten years ago. Adolescents' PA levels for the monitored periods of 1998-2000 and 2008-2010 suggest a secular decrease in the weekly number of steps achieved by adolescent boys and girls.

CONCLUSION

In the younger cohort (2008-2010), every tenth adolescent was either overweight or obese; roughly twice the rate when compared to the older cohort (1998-2000). Sedentary behaviour seems relatively stable across the two cohorts as the increased time that the younger cohort (2008-2010) spent on computers is compensated with an equally decreased time spent watching TV or studying. Across both cohorts about half to three quarters of the adolescents met the health-related criterion for achieved number of steps. The findings show a secular decrease in PA amongst adolescents. The significant interaction effects (cohort × age; and cohort × gender) that this study found suggested that secular trends in PA differ by age and gender.

Prevalence and correlates of self-induced vomiting as weight-control strategy among adolescents in Taiwan

AIMS

This study was designed to assess the prevalence and correlates of self-induced vomiting to control body weight among adolescents in Taiwan.

BACKGROUND

Over the past decades, the rate of obesity among children in Taiwan has nearly tripled. Educational authorities have devoted considerable effort to prevent the increase in childhood obesity.

DESIGN

An observational exploratory design to investigate the problem of using unhealthy weight-reduction strategy.

METHODS

This study consists of a cross-sectional study aimed at collecting national representative data. We chose 120 representative schools using a three-stage stratified systematic sampling design with probability proportionate to the size of the population in Taiwan. Participants consisted of 8673 girls and 7043 boys, aged 10-18 old.

RESULTS

Of the participants, 13% reported using self-induced vomiting, the prevalence being highest in participants aged 10-12 (15·9%) and lowest in participants aged 16-18 (7·5%). Several factors were significantly and positively associated with the use of self-induced vomiting as a weight-loss strategy, specifically subjects who (1) watched television, used computer, surfed the Internet or played video games for greater than or equal to two hours/day, (2) consumed fried food every day and (3) ate night-time snacks every day (odds ratio = 1·55, 2·10 and 1·51, respectively; p < 0·05). Eating breakfast every day and sleeping for more than eight hours a day were both protective factors against the use of self-induced vomiting to control body weight (odds ratio = 0·43 and 0·86, respectively; p < 0·05).

CONCLUSIONS

Self-induced vomiting was prevalent among adolescents who had tried to lose weight; sedentary lifestyle, shorter sleep length and unhealthy eating habits may contribute significantly to this behaviour among these adolescents.

RELEVANCE TO CLINICAL PRACTICE

School nurses who are helping adolescents lose weight should also pay attention to the possibility they are using self-induced vomiting as a weight-control strategy.

Low defaecation frequency in Taiwanese adolescents: association with dietary intake, physical activity and sedentary behaviour

AIM

The objectives of this study were to estimate the prevalence of constipation, defined as less than three defaecations per week, in Taiwanese adolescents and to examine its association with the intake of vegetables, fruits and fluids; time spent on sedentary behaviour; and time spent on moderate and vigorous physical activity.

METHODS

This study used a questionnaire survey. The study participants were 14,626 adolescents in grades 7-12. Physical activity was measured using the International Physical Activity Questionnaire-Youth Show Card Version. Time spent on sedentary activity included studying, reading, sitting in vehicles and screen time. Consumption of fluid, fruits and vegetables was measured by asking participants to describe the average consumption of each type of food in the past 7 days.

RESULTS

The prevalence of defaecation frequency of < 3 times a week was 9.3%. Multivariate logistic regression analysis showed that female sex (odds ratio (OR) = 2.2), worse health status (OR = 1.3), not being overweight/obese (OR = 0.7 and 0.3 for overweight and obesity), more time spent on sedentary activity (OR = 1.0) and low intake of fluids (< 1.8 L/day; OR = 1.2), fruits (< 1 portion; OR = 1.6), vegetables (< 1 portion or 100 g; OR = 1.4) and whole-grain products (OR = 1.2) were independently associated with increased risk of low defaecation frequency.

CONCLUSIONS

The prevalence of low defaecation frequency was high in Taiwanese adolescents. Decreasing sedentary behaviour and increasing the intake of fluids, vegetables, fruits and whole-grain products among those adolescents with very low intake levels could be helpful in preventing and managing constipation, irrespective of body size and health status.