Screen Time Correlates of Bullying Perpetration and Victimization in Brazilian Adolescents.

This study is an investigation of the associations of time spent in different screen time activities with bullying among Brazilian adolescents. In this cross-sectional study, adolescents answered questions related to bullying in the past 30 days and reported the weekly volume of screen time spent studying, working, watching videos, playing video games, and using social media applications. Multilevel logistic regression models were used. Our results indicate that higher social media use was associated with higher odds of bullying victimization among males but not females. Excessive use of screen time for work and social media purposes was associated with a higher likelihood of bullying victimization.

Cross-Sectional Associations of Screen Time Activities With Alcohol and Tobacco Consumption Among Brazilian Adolescents.

Objectives: Little is known about the association between specific types of screen time and adolescents' substance use. Thus, this study aimed to investigate the associations between screen time for studying, working, watching movies, playing games, and using social media and frequency of alcohol and tobacco use. Methods: In this cross-sectional study, Brazilian adolescents answered survey questions related to frequency of tobacco and alcohol consumption, and reported their daily volume of five types of screen time. Multilevel ordered logistic regression models were performed. Results: Each 1-hour increase in ST for studying was associated with 26% lower odds of smoking (OR = 0.74; 95% CI: 0.61-0.90) and 17% lower odds of drinking alcohol (OR = 0.83; 95% CI: 0.76-0.91) in the past 30 days. The increase of 1 hour of social media use was associated with 10% greater odds of smoking (OR = 1.10; 95% CI: 1.02-1.18) and a 13% greater chance of consuming alcohol (OR = 1.13; 95% CI: 1.08-1.18) in the past 30 days. Conclusion: The association between screen time and substance use appears to be type-specific. Future longitudinal research is needed to explore causal relationships.

Bidirectional Daily Associations Between Accelerometer-Measured Sleep and Physical Activity in Brazilian High School Students.

PURPOSE: This study analyzed day-to-day estimates of bidirectional associations between sleep parameters and intensity-specific physical activity and assessed whether the timing of physical activity influences these relationships. METHODS: The sample was comprised of 651 high school students (51.2% female, 16.33 [1.0] y old) from southern Brazil. Physical activity and sleep were measured using accelerometers. Multilevel models were applied to test associations of nocturnal total sleep time, onset, and efficiency with moderate to vigorous and light (LPA) physical activity. RESULTS: Higher engagement in moderate to vigorous physical activity and LPA was associated with increased total sleep time, and this effect was greater when physical activity was performed in the morning. Morning and evening LPA were associated with increased sleep efficiency and reduced total sleep time, respectively. Practice of LPA in the morning leads to early sleep onset, whereas evening LPA was associated with later onset. Higher total sleep time and later sleep onset were associated with lower moderate to vigorous physical activity and LPA on the following day. However, higher sleep efficiency was associated with increased LPA. CONCLUSION: The relationship between sleep parameters and physical activity is bidirectional and dependent on physical activity intensity and timing.

Socioeconomic inequalities in the consumption of minimally processed and ultra-processed foods in Brazilian adolescents.

In this study, we evaluated socioeconomic inequalities in the consumption of in natura/minimally processed and ultra-processed foods among adolescents. We used data from the Brazilian National Survey of School Health (PeNSE), 2015. According to the self-reported consumption of beans, vegetables and fruits, a score of in natura/minimally processed foods was generated (0-21 points). Sodas, sweets, instant noodles, and ultra-processed meat were used for the score of ultra-processed foods (0-21 points). Equality indicators were gender, maternal education, and socioeconomic level. Absolute difference, ratios, concentration index and slope index of inequality were calculated. Adolescents (n=101,689, 51% girls, 14.2 years) reported a mean score of 9.97 and 11.46 for ultra-processed foods and in natura/minimally processed foods, respectively. Absolute and relative differences between adolescents with the highest and lowest socioeconomic level, there were differences of 2.64 points and 33% for consumption of in natura/minimally processed foods; and 1.48 points and 15% for ultra-processed foods. Adolescents from higher socioeconomic level ate more in natura/minimally processed foods and ultra-processed foods.

Socioeconomic inequalities in the consumption of minimally processed and ultra-processed foods in Brazilian adolescents / Desigualdades socioeconômicas no consumo de alimentos minimamente processados e ultraprocessados em adolescentes no Brasil

Abstract In this study, we evaluated socioeconomic inequalities in the consumption of in natura/minimally processed and ultra-processed foods among adolescents. We used data from the Brazilian National Survey of School Health (PeNSE), 2015. According to the self-reported consumption of beans, vegetables and fruits, a score of in natura/minimally processed foods was generated (0-21 points). Sodas, sweets, instant noodles, and ultra-processed meat were used for the score of ultra-processed foods (0-21 points). Equality indicators were gender, maternal education, and socioeconomic level. Absolute difference, ratios, concentration index and slope index of inequality were calculated. Adolescents (n=101,689, 51% girls, 14.2 years) reported a mean score of 9.97 and 11.46 for ultra-processed foods and in natura/minimally processed foods, respectively. Absolute and relative differences between adolescents with the highest and lowest socioeconomic level, there were differences of 2.64 points and 33% for consumption of in natura/minimally processed foods; and 1.48 points and 15% for ultra-processed foods. Adolescents from higher socioeconomic level ate more in natura/minimally processed foods and ultra-processed foods.

Resumo Nesse estudo, avaliamos as desigualdades socioeconômicas no consumo de alimentos in natura/minimamente processados e ultraprocessados entre adolescentes. Foram utilizados dados da Pesquisa Nacional de Saúde do Escolar (PeNSE), 2015. De acordo com o consumo autorrelatado de feijão, hortaliças e frutas, foi gerado um escore de alimentos in natura/minimamente processados (0-21 pontos). Refrigerantes, doces, macarrão instantâneo e carnes ultraprocessadas prontos para o consumo foram utilizados para a pontuação dos alimentos ultraprocessados (0-21 pontos). Os indicadores de equidade foram gênero, educação materna e nível socioeconômico. Foram calculados a diferença absoluta, razões, índice de concentração e índice de inclinação de desigualdade. Os adolescentes (n=101.689, 51% meninas, 14,2 anos) relataram escore médio de 9,97 e 11,46 para alimentos ultraprocessados e in natura/minimamente processados, respectivamente. As diferenças absolutas entre os adolescentes de alto e baixo nível socioeconômico foram mais altos e mais baixos, houve diferenças de 2,64 pontos e 33% para o consumo de alimentos in natura/minimamente processados; e 1,48 pontos e 15% para alimentos ultraprocessados. Adolescentes de níveis socioeconômicos mais elevados comeram mais alimentos in natura/minimamente processados e alimentos ultraprocessados comparado aos seus pares.

Movement behaviors and their association with depressive symptoms in Brazilian adolescents: A cross-sectional study.

BACKGROUND: Physical activity, sleep, and sedentary behaviors compose 24-h movement behaviors and have been independently associated with depressive symptoms. However, it is not clear whether it is the movement behavior itself or other contextual factors that are related to depressive symptoms. The objective of the present study was to examine the associations between self-reported and accelerometer-measured movement behaviors and depressive symptoms in adolescents. METHODS: Cross-sectional data from 610 adolescents (14-18 years old) were used. Adolescents answered questions from the Center for Epidemiological Studies Depression scale and reported time spent watching videos, playing videogames, using social media, time spent in various physical activities, and daytime sleepiness. Wrist-worn accelerometers were used to measure sleep duration, sleep efficiency, sedentary time, and physical activity. Mixed-effects logistic regressions were used. RESULTS: Almost half of the adolescents (48%) were classified as being at high risk for depression (score ≥20). No significant associations were found between depressive symptoms and accelerometer-measured movement behaviors, self-reported non-sport physical activity, watching videos, and playing videogames. However, higher levels of self-reported total physical activity (odd ratio (OR) = 0.92, 95% confidence interval (95%CI): 0.86-0.98) and volume of sports (OR = 0.88, 95%CI: 0.79-0.97), in minutes, were associated with a lower risk of depression, while using social media for either 2.0-3.9 h/day (OR = 1.77, 95%CI: 1.58-2.70) or >3.9 h/day (OR = 1.67, 95%CI: 1.10-2.54), as well as higher levels of daytime sleepiness (OR = 1.17, 95%CI: 1.12-1.22), were associated with a higher risk of depression. CONCLUSION: What adolescents do when they are active or sedentary may be more important than the time spent in the movement behaviors because it relates to depressive symptoms. Targeting daytime sleepiness, promoting sports, and limiting social media use may benefit adolescents.

Associations between Sociodemographic, Dietary, and Substance Use Factors with Self-Reported 24-Hour Movement Behaviors in a Sample of Brazilian Adolescents.

We aimed to identify sociodemographic, dietary, and substance use factors associated with self-reported sleep duration, physical activity (PA), and sedentary behavior (SB) indicators in a sample of Brazilian adolescents. Adolescents (n = 731, 51% female, mean age: 16.4 years) answered a questionnaire. The volume of total PA, sports, non-sports, total SB, leisure-time SB, involuntary SB, sleep duration, dietary behaviors, sociodemographic, and substance use indicators were self-reported. Multilevel linear models were fitted. Females engaged in less total PA, sports, total SB, and leisure-time SB, but in more involuntary SB than males. Age was positively associated with non-sports and involuntary SB. Socioeconomic status was positively associated with total PA. Adolescents who lived with the mother only practiced more sports compared to those living with two parents. Unprocessed food was positively associated with total PA and sports. Processed food was inversely associated with total PA and non-sports, and positively associated with total SB and leisure-time SB. Alcohol use was positively associated with total PA, and tobacco smoking was negatively associated with total PA. No associations were observed for sleep duration. In conclusion, sociodemographic, dietary, and substance use factors are associated with the 24 h movement behaviors among Brazilian adolescents, and some associations are type specific.

How do adolescents with short sleep duration spend their extra waking hours? A device-based analysis of physical activity and sedentary behaviour in a Brazilian sample.

OBJECTIVES: To compare sedentary behaviour and physical activity between short sleepers and adequate sleepers in a sample of Brazilian adolescents. MATERIAL AND METHODS: 688 adolescents wore accelerometers on the non-dominant wrist for seven days. Sleep duration, sedentary behaviour, light (LPA), moderate (MPA), and vigorous physical activity (VPA) were estimated. Participants were classified as short (<8h/night) or adequate sleepers (≥8h/night). The minutes and the percentage of time spent in each waking behaviour was compared between short and adequate sleepers. RESULTS: Participants were 16.3 years old, 50.4% were female, and 67.7% were short sleepers. Adequate sleepers engaged in less (min/day) sedentary behaviour (-53.46), LPA (-25.44), MPA (-4.27), and VPA (-0.63) compared to short sleepers. However, no differences were observed for the proportion of time (68% in sedentary behaviour, 28% in LPA, 3% in MPA, and <0.4% in VPA). CONCLUSION: Patterns of waking behaviours are similar between short and adequate sleepers.

Adequate sleep duration among children and adolescents: a review of the Brazil's Report Card / Duração do sono adequada entre crianças e adolescentes: revisão para o Report Card Brazil

abstract - This study aimed to summarize existing research examining the prevalence of adequate sleep duration or meeting sleep recommendations among Brazilian children and adolescents. A systematic review was conducted on eight databases. The criteria for inclusion were original research, samples including Brazilian children and adolescents (age 0-18), studies that reported variables regarding sleep duration using both objective or subjective measures, school- or population-based surveys with random sampling, and cross-sectional or cohort studies. Of the 54 articles included, only 27 used data from different studies. Most of the studies were conducted in the southern region (n = 17) with only two studies having a nationally representative sample. Two studies included children below age five, and the age group most investigated was adolescents (>10 years old). A majority of the studies used a self-reported questionnaire and showed variability in the cutoff point applied for adequate sleep duration with the most reported being ≥8 hours. The proportion of adolescents who met recommendations or had adequate sleep duration ranged from 15% to 89%. Among children, the prevalence ranged from 17% to 95%. The least variability was observed among toddlers, ranging from 93% to 95%. No consistent gender differences were observed among the gender-stratified groups of children and adolescents across the studies. It can be observed that, because of the wide range of results and the lack of data with national representativeness, the prevalence of sufficient sleep among young people aged below 18 remains undefined in Brazil.

resumo - Objetivou-se resumir os estudos existentes que examinaram a prevalência de duração adequada do sono ou atendimento às recomendações de sono entre crianças e adolescentes brasileiros. Uma revisão sistemática foi realizada em oito bases de dados. Os critérios de inclusão foram pesquisas originais, amostras incluindo crianças e adolescentes brasileiros (de 0 a 18 anos), estudos que relataram variáveis ​​relacionadas à duração do sono usando medidas objetivas ou subjetivas, pesquisas baseadas na escola ou na população com amostragem aleatória e transversal ou estudos de coorte. Dos 54 artigos incluídos, apenas 27 utilizaram dados de estudos diferentes. A maioria dos estudos foi realizada na região sul (n = 17), com apenas dois estudos tendo uma amostra representativa nacionalmente. Dois estudos incluíram crianças menores de cinco anos, e a faixa etária mais investigada foi de adolescentes (> 10 anos). A maioria dos estudos utilizou um questionário autorreferido e mostrou variabilidade no ponto de corte aplicado para a duração adequada do sono com a maioria relatada sendo ≥8 horas. A proporção de adolescentes que cumpriram as recomendações ou tiveram uma duração de sono adequada variou de 15% a 89%. Entre as crianças, a prevalência variou de 17% a 95%. A menor variabilidade foi observada entre as crianças, variando de 93% a 95%. Nenhuma diferença de gênero consistente foi observada entre os grupos. Observa-se que, pela ampla variabilidade de resultados e pela carência de dados com representatividade nacional, a prevalência de sono suficiente em jovens com menos de 18 anos permanece indefinida no Brasil.

Association between Lifestyle Behaviors and Health-Related Quality of Life in a Sample of Brazilian Adolescents.

This study aimed to analyze the association between lifestyle behaviors and health-related quality of life (HRQoL) among Brazilian adolescents. We evaluated 739 adolescents (51.0% girls; mean age, 16.4 ± 1.0 years) from the mesoregion Grande Florianópolis, Brazil. Participants were asked to complete an online questionnaire and sex, age, mother's education, health-related quality of life, physical activity, screen time indicators, sleep duration, diet, cigarette smoking, alcohol drinking, and drug experimentation were retrieved. Health-related quality of life was assessed using the Kidscreen-10 instrument. Measures of body mass and height were taken by trained researchers. Mixed-effects linear regression models were used. Self-reported health-related quality of life was higher in males (ß = 3.68, 95%CI: 2.75; 4.61) compared to females, and no association was observed for age and mother's education level. Practicing sports (ß = 1.19, 95%CI: 0.29; 2.08) was associated with better HRQoL, while processed food score (ß = -0.45, 95%CI: -0.78; -0.13), working using screen devices for more than 4 h/day (ß = -2.38, 95%CI: -4.52; -0.25), having experimented illicit drugs (ß = -2.05, 95%CI: -3.20; -0.90), and sleeping less than 8 h/night (ß = -1.35, 95%CI: -2.27; -0.43) were unfavorably associated with HRQoL. Non-sport physical activities, unprocessed food, studying, watching videos, playing videogames, using social media, alcohol drinking, and smoking were not associated with health-related quality of life. These findings suggest that promoting sports and adequate sleep, and preventing excessive workloads and the use of drugs among adolescents may be effective strategies to improve HRQoL.

Correlates of compliance with hip-worn accelerometer protocol in adolescents / Aderência a protocolo de uso de acelerômetros no quadril em adolescentes

Accelerometers are widely used to measure physical activity and sedentary behaviour amongst youth, and research participants have to wear the accelerometer for enough time to provide valid estimates of their habitual behaviour. This study aimed to identify correlates of accelerometer wear time in a sample (n = 142) of Brazilian adolescents of the 7th to the 9th grade. Students of two middle schools of Florianopolis were invited to participate. The participants answered a questionnaire, wore an accelerometer on the right hip for 10-12 days, and had their height and weight measured. The association of gender, age, socioeconomic position, mother education, conicity index, and self-reported physical activity with accelerometer wear time (minutes), number of days with ≥ 10h of valid accelerometer data, and compliance with validation criteria (≥ 4 days with ≥ 10h of wear time, including a week-end day) were tested. Accelerometer wear time in minutes was lower in boys than girls (-1014.14, 95%CI: -1822.91; -205.37). Boys also had less valid days compared to girls (Incidence Risk Ratio = 0.70; 95%CI: 0.52; 0.94) and were less likely to comply with validation criteria (Odds Ratio = 0.29; 95%CI: 0.12; 0.68). Higher mother education was associated with increased odds of meeting validation criteria. Factors associated with compliance with accelerometer protocol were sex and mother education. Thus, analyzes should consider the difference in representation of such groups

Acelerômetros são amplamente utilizados para mensuração da atividade física e comportamento sedentário de jovens, e participantes devem utilizar o acelerômetro por tempo o suficiente para fornecer estimativas de seu comportamento habitual. O presente estudo objetivou identificar correlatos do tempo de uso de acelerômetro em uma amostra (n = 142)de adolescentes brasileiros do sétimo ao nono ano. Estudantes de duas escolas de ensino fundamental de Florianópolis foram convidados. Os participantes responderam a um questionário, utilizaram um acelerômetro no quadril direito por 10 a 12 dias e tiveram sua estatura e massa corporal mensuradas. Foram testadas associações de sexo, idade, posição socioeconômica, educação maternal, índice de conicidade e atividade física autorrelatada com tempo de uso do acelerômetro (minutos), número de dias válidos com ≥ 10h válidas de dados de acelerômetro e aderência aos critérios de validação dos dados (≥ 4 dias com ≥ 10h de tempo de uso, incluindo um dia de final de semana). O tempo de uso do acelerômetro em minutos foi menor em meninos do que nas meninas (-1014,14; IC95%: -1822,91; -205,37). Meninos apresentaram menos dias válidos comparadas as meninas (Razão de Risco de Incidência = 0,70; IC95%: 0,52; 0,94) e tiveram uma menor probabilidade de atender aos critérios de validação (Razão de Chance = 0.29; IC95%: 0.12; 0.68). Maior educação materna foi associada com maior chance de atender aos critérios de validação. Fatores associados à aderência ao protocolo de uso dos acelerômetros foram sexo e escolaridade materna. Por-tanto, análises devem considerar diferenças na representação dentre estes grupos

Are adolescents really being sedentary or inactive when at school? An analysis of sedentary behaviour and physical activity bouts.

This study analysed physical activity (PA) and sedentary behaviour (SB) performed in bouts during schooltime. Adolescents of two schools answered a questionnaire, had their height and weight measured and wore accelerometers during schooltime. Moderate-to-vigorous intensity PA was estimated in bouts of 2, 5 and 10 min, and SB in bouts of 5, 10, 30 and 60 min. Body mass index was calculated, and adolescents were classified as overweight or normal weight. Frequency, duration and volume of PA and SB were calculated for the whole sample and for those who performed at least one bout weekly. PA and SB differences between gender and weight status were tested using Mann-Whitney and t tests. A total of 415 adolescents (54% girls, 12.3 ± 1.3 years old, 34.6% overweight) performed 0.1 (± 0.2), 0.2 (± 0.5) and 0.4 (± 0.6) bouts of 10, 5 and 2 min of PA, and 10.6 (± 2.0), 6.0 (± 1.3), 1.1 (± 0.9) and 0.4 (± 0.5) bouts/day of 5, 10, 30 and 60 min of SB, respectively. Boys accumulated less SB and more PA in bouts. No differences were found for weight status.Conclusion: Adolescents hardly engaged in bouted PA and accumulated more SB in smaller bouts during schooltime. Bouted PA and SB were not associated with weight status. What is Known: • Adolescents are not engaging in enough PA and are accumulating large volumes of SB, which might negatively impact their health. • Schools play an important role in daily overall PA, with opportunities such as PE classes and recesses. But most classes are still undertaken in seated positions. What is New: • Adolescents hardly engage in bouted (> 10 m) PA when at school., and most SB is accumulated in short bouts (≤ 10m). • Weight status was not associated with bouted PA or SB at school.

Systematic review of childhood and adolescence sedentary behavior: analysis of the Report Card Brazil 2018 / Revisão sistemática do comportamento sedentário na infância e adolescência: análise do Report Card Brasil 2018

Abstract The aim of this study was to summarize studies examining the prevalence of sedentary behavior among Brazilian children and adolescents. A systematic review conducted on eight databases (PubMed, Scopus, Web of Science, LILACS, SPORTDiscus, BIREME, Scielo, and Google Scholar). The criteria applied were: original research; samples including Brazilian children and adolescents; to be a school- or population-based survey; observational studies using different measures of sedentary behavior; studies showing the prevalence of at least one component of sedentary behavior. Of the 205 studies included, 104 were analyzed. There was a greater concentration of studies in the southern (n=41) and northeastern (n=18) regions. The components more frequently investigated were watching TV (n=36) and screen time (n=32). Only three studies included children under seven years, and the age range more investigated was 10 to 19 years. Most of the studies used a self-reported questionnaire and showed variability in the cut-off point applied (from 2 to 4 hours/day). The prevalence of adolescents who met recommendations ranged from 9.4% to 68.0% for sedentary behavior (<2 hours/day) and from 16.8% to 67.2% for TV viewing (<2 hours/day). The prevalence ranged from 39.1% to 97.7% for computer use and from 47.7% to 98.0% for videogame use. Most of the studies reported that less than half of the adolescents met the recommendations of sedentary behavior and TV viewing. On the other hand, more than half of them devoted less than two hours a day to computer and videogame use.

Resumo Objetivou-se sintetizar estudos que estimaram a prevalência de comportamento sedentário (CS) em crianças e adolescentes. Revisão sistemática conduzida em oito base de dados (PubMed, Scopus, Web of Science, LILACS, SPORTDiscus, BIREME, Scielo, and Google Scholar). Os critérios utilizados foram: artigos originais; amostras incluindo crianças e adolescentes; levantamentos de base escolar e populacional; estudos observacionais usando diferentes medida do CS; estudos mostrando a prevalência de pelo menos um componente do CS. Dos 205 estudos incluídos, 104 foram analisados. Houve maior concentração de estudos nas regiões Sul (n=41) e Nordeste (n=18). Os componentes mais investigados foram assistência à TV (n=36) e tempo de tela (n=32). Somente três estudos incluíram dados de crianças com menos de sete anos, e a maioria investigou adolescentes de 10 a 19 anos. A maioria dos estudos usou questionários e apresentou variabilidade no ponto de corte utilizado (de 2 a 4 horas). A prevalência de adolescentes que atendiam às recomendações de CS (<2 horas/dia) variou de 9,4% a 68,0%. A prevalência de adolescentes que assistiam TV (<2 horas/dia) foi de 16,8% a 67,2%. Para o uso de computador, a prevalência variou de 39,1% a 97,7%; e de 47,7% a 98,0% para o videogame. Na maioria dos estudos menos da metade dos adolescentes atendeu às recomendações de CS e de tempo de TV. Por outro lado, mais da metade deles apresentou tempo inferior a duas horas por dia para o uso de computador e videogame.