Individual and school correlates of body mass index and cardiorespiratory fitness in primary school children from the REACT project: A multivariate multilevel analysis.

OBJECTIVE: This paper examines the relationship between body mass index (BMI) and cardiorespiratory fitness (CRF) using a multivariate multilevel approach and investigates the links between individual and school-related correlates with children's BMI and CRF. METHODS: This cross-sectional sample included 1014 children (6-10 years) from 25 Portuguese primary schools. BMI was calculated, and CRF was assessed with the PACER test. Fundamental movement skills (FMS) included five object control tasks. Moderate-to-vigorous physical activity (MVPA), sleep, and sedentary time were assessed with the ActiGraph wGT3X-BT accelerometer. Socioeconomic status (SES) and school variables were also obtained. A multivariate multilevel model was used, and alpha was set at 5%. RESULTS: BMI and CRF systematically increased with age. Most of the joint variance (94.4%) was explained at the child level, and BMI and CRF were correlated at this level (ρ = -.37). More active children demonstrated higher CRF levels and had lower BMI levels; sedentary and sleep time were not significantly associated with BMI or CRF. FMS were positively associated with CRF but were not significantly associated with BMI. Children at higher SES were more fit and had lower BMI than their peers of lower SES. Finally, school-level variables were not significantly related to BMI and CRF. CONCLUSION: BMI and CRF had a low but statistically significant negative correlation in this sample of children. Most of the variation in BMI and CRF was explained by child-level characteristics.

A multivariate multilevel approach to unravel the associations between individual and school factors on children's motor performance in the REACT project.

OBJECTIVE: The aim was to (1) estimate the relationship between physical fitness (PF) and object control fundamental movement skills (FMS), (2) identify child characteristics that relate with PF and FMS, and (3) examine associations between the school environment, PF, and FMS. METHODS: The sample included 1014 Portuguese children aged 6-10 years from the REACT project. PF was assessed via running speed, shuttle run, standing long jump, handgrip, and the PACER test. Object control FMS were assessed with stationary dribble, kick, catch, overhand throw, and underhand roll. Test performances were transformed into z-scores, and their sum was expressed as overall PF and FMS. Child-level variables included body mass index (BMI) z-scores, accelerometer-measured sedentary time and moderate-to-vigorous physical activity, and socioeconomic status (SES). School size, physical education classes, practice areas, and equipment were also assessed. RESULTS: Approximately, 90% of the variance in object control PF and FMS was at the child level, and 10% at the school level. The correlation between PF and object control FMS was .62, which declined to .43 with the inclusion of covariates. Older, more active, and higher SES children had higher object control PF and FMS, and boys outperformed girls. BMI was negatively associated with PF but not with object control FMS. Sedentary time and number of physical education classes were not significant predictors. Most school predictors did not jointly associate with PF and object control FMS. CONCLUSION: PF and object control FMS z-scores were moderately related. Not all child characteristics were associated with both PF and object control FMS, and their effect sizes were different. School characteristics only explained 10% of the total variation in PF and object control FMS.

Is there an association between proficiency in fundamental movement skills and mderate-to-vigorous physical activity in childhood on weekdays and weekends? The REACT project.

OBJECTIVE: The present study probes into the association between children's fundamental movement skills (FMS) and moderate-to-vigorous physical activity (MVPA) during weekdays and weekends. METHODS: This cross-sectional sample included 1014 children aged 6-10 years from the REACT project. Physical activity was assessed with accelerometry, and five FMS (stationary dribble, kick, catch, overhand throw, and underhand roll) were assessed with the digital platform Meu Educativo®. Three groups were formed based on the frequency of FMS that each child mastered: group 1 (wizard level in four or five FMS); group 2 (wizard level in two or three FMS); and group 3 (wizard level in at most one skill). Multilevel models were used to analyze the data treating children (level-1) nested within schools (level-2). RESULTS: Compared to group 1, groups 2 (-12.9 ± 2.3 min day-1) and 3 (-23.9 ± 2.4 min day-1) were less physically active during weekdays and weekends (group 2: -14.7 ± 2.7 min day-1 and group 3: -22.4 ± 2.9 min day-1), independent of age and sex. There was a decline in MVPA during the weekend. Further, on average, boys were more active than girls, and with increasing age, children were less active. CONCLUSION: On average, children with higher FMS levels are generally more physically active than their peers with lower FMS levels. Even though MVPA tends to decline on weekends, FMS proficiency is a significant factor in maintaining 60 min of MVPA on weekends.

Associations of obesity, movement behaviors, and socioeconomic status with fundamental movement skills in children: Results from the REACT project.

OBJECTIVE: To investigate the relationship of biological characteristics (age, sex, and obesity), movement behaviors (physical activity and sedentary time), and family socioeconomic status with fundamental movement skills (FMS) in primary school children. METHODS: This cross-sectional study sampled 1014 children (537 girls) aged 6 to 10 years from 25 primary schools in Matosinhos, north of Portugal. Five object control skills (dribbling, kicking, catching, throwing, and underarm rolling) were assessed with a categorical scale using the Meu Educativo® platform. Body Mass Index (BMI) was calculated and transformed into z-scores. Moderate-to-vigorous physical activity (MVPA) and sedentary time were monitored with accelerometry (ActiGraph wGT3X-BT) for seven consecutive days. Family socioeconomic status (SES) was obtained from the Portuguese social support system. Ordinal multilevel logistic regression was used to analyze the associations of weight status, MVPA, sedentary time and SES with FMS, adjusted for sex and age. RESULTS: Boys (odds ratio (OR) = 6.54; 95% CI: 5.13-8.36) and older children (OR = 2.04; 95% CI: 1.85-2.26) were more likely to achieve higher FMS scores. Children with obesity (OR = 0.60; 95% CI: 0.45-0.80), those less active (OR = 0.56; 95% CI: 0.42-0.75) and children with more sedentary time (OR = 0.86; 95%CI: 0.77-0.97) were less likely to score high on FMS. Family SES was not significantly associated with FMS scores. CONCLUSION: Primary school children's FMS are significantly related to biological and behavioral factors but not to family SES. These findings highlight the need for suitable strategies to enhance children's FMS proficiency, considering differences in these characteristics. Fostering adequate motor skill proficiency levels will assist in establishing a robust foundation for healthy lifestyles of all children.

Food Insecurity and Premature Mortality and Life Expectancy in the US.

Importance: Food insecurity has been linked to multiple causes of disease and premature mortality; however, its association with mortality by sex and across racial and ethnic groups remains unknown in the US. Objective: To investigate the associations of the entire range of food security with all-cause premature mortality and life expectancy across racial and ethnic and sex groups in US adults. Design, Setting, and Participants: This cohort study included adults (aged ≥18 years) who participated in the National Health and Nutrition Examination Survey from 1999 to 2018, with linkage to the National Death Index through December 31, 2019. Data analysis was performed from August to November 2023. Exposures: Levels of food security were assessed with the US Department of Agriculture Adult Food Security Survey Module (full, marginal, low, and very low). Main Outcomes and Measures: All-cause premature mortality (death that occurs before age 80 years) and life expectancy. Results: The study included 57 404 adults (weighted mean [SE] age, 46.0 [0.19] years; 51.8% female; 12 281 Black individuals [21.4%]; 10 421 Mexican individuals [18.2%]; 4627 Other Hispanic individuals [8.1%]; 24 817 White individuals [43.2%]; and 5258 individuals of other races, including multiracial [9.2%]). During a median (IQR) of 9.3 (5.0-14.3) years of follow-up, 4263 premature deaths were documented. Compared with the full food security group, the adjusted hazard ratios were 1.50 (95% CI, 1.31-1.71), 1.44 (95% CI, 1.24-1.68), and 1.81 (95% CI, 1.56-2.10) across marginal, low, and very low food security groups, respectively (P < .001 for trend). The corresponding life expectancy at age 50 years in each group was 32.5 (95% CI, 32.4-32.6), 29.9 (95% CI, 28.9-30.9), 30.0 (95% CI, 28.9-31.0), and 28.0 (95% CI, 26.8-29.2) years. Equivalently, adults with marginal, low, or very low food security lived on average 2.6 (95% CI, 1.5-3.7), 2.5 (95% CI, 1.4-3.7), or 4.5 (95% CI, 3.2-5.8) fewer years at age 50 years, respectively, compared with those with full food security. The associations appeared to be stronger in women than in men (hazard ratios comparing very low food security with full food security, 2.29 [95% CI, 1.83-2.86] in women and 1.46 [95% CI, 1.19-1.78] in men; P = .009 for interaction) and stronger in White adults than in Black adults (hazard ratios comparing very low food security with full food security, 2.07 [95% CI, 1.70-2.53] in White adults and 1.33 [95% CI, 1.01-1.75] in Black adults; P < .001 for interaction) or in Hispanic adults (hazard ratios comparing very low food security with full food security, 1.06 [95% CI, 0.71-1.58]; P < .001 for interaction). Conclusions and Relevance: In this cohort study, although the association of food security and life expectancy varied across sex and racial and ethnic groups, overall, lower levels of food security were associated with a higher risk of premature mortality and a shorter life expectancy. The findings of this study highlight the potential importance of improving food security in promoting population health and health equity.

Computed Tomography and Dual-Energy X-Ray Asorptiometry body composition parameter harmonisation to universalise adipose tissue measurements in a population-based cross-sectional study.

To harmonise computed tomography (CT) and dual-energy x-ray absorptiometry (DXA) body composition measurements allowing easy conversion in longitudinal assessments and across cohorts to assess cardiometabolic risk and disease. Retrospective cross-sectional observational study from 1996 to 2008 included participants in the Pennington Center Longitudinal Study (PCLS) (N = 1967; 571 African American/1396 White). Anthropometrics, whole-body DXA and abdominal CT images were obtained. Multi-layer segmentation techniques (Analyze; Rochester, MN) quantified visceral adipose tissue (VAT). Clinical biomarkers were obtained from routine blood samples. Linear models were used to predict CT-VAT from DXA-VAT and examine the effects of traditional biomarkers on cross-sectional-VAT. Predicted CT-VAT was highly associated with measured CT-VAT using ordinary least square linear regression analysis and random forest models (R2 = 0.84; 0.94, respectively, p < .0001). Model stratification effects showed low variability between races and sexes. Overall, associations between measured CT-VAT and DXA-predicted CT-VAT were good (R2 > 0.7) or excellent (R2 > 0.8) and improved for all stratification groups except African American men using random forest models. The clinical effects on measured CT-VAT and DXA-VAT showed no significant clinical difference in the measured adipose tissue areas (mean difference = 0.22 cm2). Random forest modelling seamlessly predicts CT-VAT from measured DXA-VAT to a degree of accuracy that falls within the bounds of universally accepted standard error.

Perfil de atividade física no tempo livre e tempo sedentário em adultos no Brasil: inquérito nacional, 2019 / Profile of leisure-time physical activity and sedentary behavior in adults in Brazil: a nationwide survey, 2019 / Perfil de la actividad física en el tiempo libre y sedentario em adultos en Brasil: encuesta nacional, 2019

Objetivos: estimar a prevalência de atividade física no tempo livre e comportamento sedentário em adultos no Brasil. Métodos: estudo seccional, populacional, na amostra de 88.531 brasileiros da Pesquisa Nacional de Saúde de 2019; a atividade física (geral e modalidades aeróbias) no tempo livre foi mensurada conforme as diretrizes da Organização Mundial da Saúde; estimaram-se as prevalências ponderadas, e respectivos intervalos de confiança de 95% (IC95%), de atividade física, inatividade física e tempo sedentário. Resultados: a partir da amostra selecionada, 26,4% (IC95% 25,9;27,1) dos adultos brasileiros eram fisicamente ativos, 14,0% (IC95% 13,5;14,4) eram insuficientemente ativos e 59,5% (IC95% 58,8;60,2) eram inativos; o tempo sedentário ≥ 6 horas foi relatado por 30,1% (IC95% 29,5;30,8) da população; apenas 8,6% (IC95% 8,2;8,9) atenderam às recomendações de atividade física para fortalecimento muscular. Conclusão: a maioria dos brasileiros adultos era inativa e não atendeu às recomendações internacionais de atividade física no tempo livre e restrição de tempo sedentário.

Objectives: to estimate the prevalence of leisure-time physical activity and sedentary behavior in adults in Brazil. Methods: this was a cross-sectional, population-based study carried out in a sample of 88,531 Brazilians, using data from the 2019 National Health Survey; leisure-time physical activity (overall and aerobic exercise) was measured according to the World Health Organization guidelines; the weighted prevalence and respective 95% confidence intervals (95%CI) of physical activity, physical inactivity and sedentary behavior were estimated. Results: according to the selected sample, 26.4% (95%CI 25.9;27.1) of Brazilian adults were physically active, 14.0% (95%CI 13.5;14.4) were insufficiently physically active and 59.5% (95%CI 58.8;60.2) were physically inactive; sedentary behavior ≥ 6 hours was reported by 30.1% (95%CI 29.5;30.8) of the population; only 8.6% (95%CI 8.2;8.9) met the recommendations for muscle-strengthening activities. Conclusion: most Brazilian adults were physically inactive and did not meet international recommendations for leisure-time physical activity and reduction in sedentary behavior.

Objetivos: estimar la prevalencia de actividad física en el tiempo libre y comportamiento sedentario de adultos en Brasil. Métodos: estudio seccional, poblacional, de la muestra de la Encuesta Nacional de Salud de 2019 a partir de lo cual, se estimó la prevalencia ponderada (porcentaje e intervalo de confianza del 95%) de actividad física (general y aeróbica), la inactividad física y el comportamiento sedentario. Resultados: según la muestra elegida, 26,4% (IC95% 25,9;27,1) son físicamente activos, 59,5% (IC95% 58,8;60,2) son inactivos, 14,0% (IC95% 13,5;14,4) son insuficientemente activos y 30,1% (IC95% 29,5;30,8) pasan ≥6 horas sedentarios en su tiempo libre; sólo el 8,6% (IC95% 8,2;8,9) de los adultos cumple con las recomendaciones de actividad física para fortalecimiento muscular. Conclusión: la mayoría de los adultos brasileños son inactivos, no cumplen con las recomendaciones internacionales de actividad física en el tiempo libre y la restricción del tiempo sedentario.

Why are children different in their moderate-to-vigorous physical activity levels? A multilevel analysis / Por que as crianças são diferentes em seus níveis de atividade física de intensidade moderada a vigorosa? Uma análise multinível

Abstract Objective: Children's differences in moderate-to-vigorous physical activity levels are not at random. This study investigates the relevance of individual- and school-level characteristics in explaining these differences. Methods: In total, 307 children (154 girls) aged 5-10 years, from 19 Portuguese schools, were sampled. Height and weight were measured, and body mass index was calculated. Time spent in moderate-to-vigorous physical activity was measured by accelerometry. Gross motor coordination was assessed with the KörperkoordinationsTest für Kinder battery and socio-economic status was obtained via the school social support system. School characteristics were obtained with an objective school audit. A multilevel analysis was used as implemented in Stata 15. Results: Schools explained 18.2% of the total variance in moderate-to-vigorous physical activity, with the remainder being ascribed to children's distinct characteristics. Boys were more active (β = 29.59 ± 11.52, p < 0.05), and having higher gross motor coordination levels (β = 0.11 ± 0.04, p < 0.05) was positively associated with daily moderate-to-vigorous physical activity, whereas being older (β = −5.00 ± 1.57, p < 0.05) and having higher socio-economic status (β = −7.89 ± 3.12, p < 0.05) were negatively related with moderate-to-vigorous physical activity. From the school-level correlates, only playground dimension was significantly associated with moderate-to-vigorous physical activity levels. Children from schools with medium (40 m2 to 69 m2) and large playground dimensions (≥70 m2) were less active than children with smaller playground dimensions (10 m2 to 39 m2). Conclusions: Variation in school children's moderate-to-vigorous physical activity is mostly explained by their individual characteristics; school characteristics also play a role but to a smaller degree. Future intervention programs to change this behavior should be more personalized, emphasizing mostly individual-level characteristics.

Resumo Objetivo As diferenças entre crianças na atividade física moderada a vigorosa não são aleatórias. Este estudo investiga a relevância das características em níveis individuais e escolares para explicar essas diferenças. Métodos Foram amostradas 307 crianças (154 meninas) entre 5 e 10 anos, de 19 escolas portuguesas. A estatura e o peso foram medidos e o índice de massa corporal foi calculado. O tempo gasto em atividade física moderada a vigorosa foi medido por acelerometria. A coordenação motora grossa foi avaliada com a bateria do Körperkoordinationstest für Kinder e o status socioeconômico foi obtido através do sistema de apoio social da escola. As características da escola foram obtidas através de uma auditoria escolar objetiva. Uma análise multinível foi utilizada como implantada no Stata 15. Resultados As escolas explicaram 18,2% da variância total da atividade física moderada a vigorosa, com o restante atribuído às diferentes características das crianças. Os meninos foram mais ativos (β = 29,59 ± 11,52, p < 0,05) e o fato de ter níveis mais altos de coordenação motora grossa (β = 0,11 ± 0,04, p < 0,05) foi positivamente associado com a atividade física moderada a vigorosa diária. Os mais velhos (β = -5,00 ± 1,57, p < 0,05) e com maior status socioeconômico (β = -7,89 ± 3,12, p < 0,05) foram negativamente relacionados com a atividade física moderada a vigorosa. Com base nos correlatos a nível escolar, apenas a dimensão da área recreativa foi significativamente associada aos níveis de atividade física moderada a vigorosa. As crianças das escolas com área recreativa média (40 m2 a 69 m2) e grande (≥ 70 m2) foram menos ativas do que as crianças com áreas recreativas com menores dimensões (10 m2 a 39 m2). Conclusões A variação na atividade física moderada a vigorosa de escolares é explicada principalmente por suas características individuais; as características da escola também desempenham um papel, mas em menor grau. Futuros programas de intervenção para mudar esse comportamento devem ser mais personalizados, enfatizar principalmente as características em nível individual.

Factors associated with objectively measured total sedentary time and screen time in children aged 9-11 years / Fatores associados do tempo sedentário total medido objetivamente e tempo de tela em crianças de 9-11 anos

Abstract Objective: To identify factors associated with total sedentary time and screen time in children aged 9-11 years. Methods: For seven consecutive days, 328 children (51.5% boys) used accelerometers to monitor total sedentary time. Screen time was calculated by the self-reporting method. Individual, family, family environment, and school environment questionnaires were filled out. Body composition was measured using a Tanita scale. Results: The mean sedentary time was 500 min/day (boys: 489, girls: 511, p = 0.005), and mean screen time was 234 min/day (boys: 246, girls: 222, p = 0.053). In both genders, factors associated with sedentary time were healthy dietary pattern and moderate-to-vigorous physical activity. In boys, only moderate-to-vigorous physical activity was significant; in girls, the healthy dietary pattern, moderate-to-vigorous physical activity, and transportation to school were significant. As for the screen time, the associated factors were body mass index and healthy dietary pattern (both genders). In boys, the associated factors were body mass index, healthy dietary pattern, and television in the bedroom. In girls, the associated factors were healthy dietary pattern, transportation to school, and physical activity policies or practice at school. Conclusion: Several associated factors were identified in the association between total sedentary time and screen time in children; however, only the healthy dietary pattern was common between sedentary time and screen time.

Resumo Objetivo: Identificar os fatores associados do tempo sedentário total e tempo de tela em crianças entre 9-11 anos. Métodos: Durante sete dias consecutivos, 328 crianças (51,5% meninos) usaram acelerômetros para monitorar o tempo sedentário total. O tempo de tela foi calculado pelo método autorreferido. Questionários com fatores individuais, familiares, ambiente familiar e escolar foram preenchidos. A composição corporal foi medida usando uma balança Tanita. Resultados: A média do tempo sedentário (min/dia) foi de 500 (meninos: 489; meninas: 511; p = 0,005), e do tempo de tela foi 234 (meninos: 246; meninas: 222; p = 0,053). Em ambos os sexos, os fatores associados do tempo sedentário foram o padrão de dieta saudável e atividade física de moderada a vigorosa. Nos meninos, apenas a atividade física de moderada a vigorosa foi significativa e nas meninas o padrão de dieta saudável, atividade física de moderada a vigorosa e transporte para a escola foi significativo. Já para o tempo de tela, os fatores associados foram o índice de massa corporal e padrão de dieta saudável (ambos os sexos). Nos meninos, os fatores associados foram o índice de massa corporal, o padrão de dieta saudável e televisão no quarto. Nas meninas, os fatores associados foram o padrão de dieta saudável, transporte para escola e políticas ou práticas de atividade física na escola. Conclusão: Vários fatores associados foram identificados entre tempo sedentário total e tempo de tela em crianças. Entretanto, somente o padrão de dieta saudável foi comum entre tempo sedentário e tempo de tela.

Correlates of body fat and waist circumference in children from São Caetano do Sul, Brazil / Correlatos da gordura corporal e circunferência da cintura em crianças de São Caetano do Sul, Brasil

Abstract The purpose of this study was to examine potential correlates of body fat (BF) and waist circumference (WC) in children. The sample included 328 children (169 boys) aged 9-11 years. BF (%) was measured using a bioelectrical impedance scale. WC measurements were made on exposed skin at the end of a normal expiration using a non-elastic anthropometric tape. Moderate-to-vigorous physical activity (MVPA) and sedentary behavior were measured using accelerometers. Participants with complete individual, family and home, and school environmental data were included in the analysis. Children averaged 21.3% in boys and 25.8% in girls for BF and 68.0 cm in boys and 67.2 cm in girls for WC. There was higher BF among girls (p<0.001), but no significant sex differences with respect to WC. In boys, breakfast consumption, bad sleep quality, and MVPA were associated with BF. Among girls, the only variables associated with BF were breakfast consumption and bad sleep quantity. Bad sleep quality and MVPA were associated with WC in boys. Among girls, WC was associated with breakfast consumption and bad sleep quantity. We identified correlates of BF and WC in children; however, few correlates were common for both BF and WC, and for both boys and girls.

Resumo O objetivo deste estudo foi examinar os potencias correlatos da gordura corporal (GC) e da circunferência da cintura (CC) em crianças. A amostra incluiu 328 crianças (169 meninos) de 9-11 anos. A GC (%) foi avaliada usando a bioimpedância elétrica e a CC (cm) usando uma fita antropométrica não elástica. A atividade física de moderada à vigorosa (AFMV) e o tempo sedentário (TS) foram mensurados usando acelerômetros. Os participantes que tinham informações completas individuais, familiares, e de ambiente da moradia e escolar foram incluídos nas análises. As médias das crianças foram 21,3% nos meninos e 25,8% nas meninas para GC e 68,0 cm nos meninos e 67,2 cm nas meninas para CC. A média das meninas foi maior do que nos meninos para GC (p<0.001). Não encontramos diferença significativa entre os sexos para CC. Nos meninos, o consumo de café da manhã, qualidade de sono ruim e AFMV foram associados com GC. Nas meninas, as únicas variáveis associadas foram o consumo do café da manhã e qualidade de sono ruim. Qualidade de sono ruim e AFMV foram associadas com CC nos meninos. Nas meninas, CC foi associada significativamente com consumo de café da manhã e qualidade do sono ruim. Identificamos correlatos da GC e da CC em crianças, no entanto, poucos correlatos foram comuns para GC e CC e em ambos os sexos.

Prevalence and factors associated with body mass index in children aged 9-11 years / Prevalência e fatores associados do índice de massa corporal em crianças de 9-11 anos de idade

Abstract Objective: This study aimed to identify the prevalence and factors associated with body mass index (BMI) in children aged 9-11 years. Methods: The study is part of the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE). Body composition was determined using the bipolar bioimpedance technique. The mean BMI value was categorized as recommended by the World Health Organization. For seven consecutive days, participants used an accelerometer to objectively monitor sedentary behavior (SB) and moderate to vigorous physical activity. Individual factors (anthropometric and behavioral), family aspects, and family and school environment were provided by participants and parents and were analyzed by multilevel linear regression adjusted for gender, ethnicity, school, number of siblings, and total annual family income. Results: The mean BMI was 20.1 kg/m2, and 51.8% of the children were overweight/obese (50.3% boys, 53.4% girls, p = 0.014). Considering all participants, the associated factors of BMI were body fat percentage (BF%, β = 0.0216, p < 0.001) and screen time (ST, β = 0.0050, p = 0.006). In boys, the associated factors were BF% (β = 0.0209, p < 0.001), ST (β = 0.006, p = 0.036), and healthy eating policies or practices (β = 0.0276, p = 0.025). In girls, only BF% was associated (β = 0.0221, p < 0.001) with BMI. Conclusions: High prevalence of overweight/obesity was observed in children from São Caetano do Sul. Different associated factors were identified between the genders, with only BF% being common in both genders.

Resumo Objetivo: Identificar a prevalência e os fatores associados do índice de massa corporal (IMC) em crianças de 9-11 anos. Métodos: O estudo faz parte do International Study of Childhood Obesity Lifestyle and the Environment (Iscole). A composição corporal foi determinada pelo método da bioimpedância bipolar. O valor médio do IMC foi categorizado conforme sugerido pela Organização Mundial de Saúde. Durante sete dias consecutivos, os participantes usaram acelerômetro para monitorar objetivamente o comportamento sedentário (CS) e atividade física de moderada a vigorosa. Fatores associados individuais (antropométricos e comportamentais), aspectos familiares, ambiente familiar e escolar foram preenchidos pelos participantes e pais e foram analisados pela regressão linear multinível ajustados para sexo, etnia, escola, número de irmãos e renda familiar total anual. Resultados: A média do IMC foi de 20,1 kg/m2, 51,8% das crianças estavam com excesso de peso/obesidade (50,3% meninos; 53,4% meninas; p = 0,014). Considerando todos os participantes, os fatores associados do IMC foram a porcentagem de gordura corporal (%GC; β = 0,0216; p < 0,001) e o tempo de tela (TT; β = 0,0050; p = 0,006). Nos meninos, os fatores associados foram a %GC (β = 0,0209; p < 0,001), TT (β = 0,006; p = 0,036) e políticas ou práticas de alimentação saudável (β = 0,0276; p = 0,025). Já nas meninas, somente a %GC foi associada (β = 0,0221; p < 0,001) com o IMC. Conclusões: Mostramos valores elevados de prevalência de excesso de peso/obesidade em crianças de São Caetano do Sul. Diferentes fatores associados foram identificados entre os sexos, somente a %GC foi comum em ambos os sexos.

A cross-cultural study of physical activity and sedentariness in youth from Mozambique and Portugal

Abstract Aim: The purpose of this study was to analyse the effects of age, sex, body mass index (BMI) and country of origin (Mozambique versus Portugal) on physical activity and sedentariness. Methods: Sample size was comprised of 593 adolescents from Mozambique (n=258) and Portugal (n=335), aged 10-15 years old. Height and weight were measured, and BMI was computed; furthermore, subjects were classified in two groups (normal weight and overweight/obese). The mean time (min/day) spent in moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and sedentary activity were assessed using the GT3X Actigraph accelerometer over at least 4 days (1 weekend day) with a minimum of 10 hours/day of monitoring. Multiple regression analysis was done in SPSS 20. Results: A low percentage of Mozambican (3.9%) and Portuguese (4.3%) youth complied with the MVPA recommendations (60min·day-1). However, Portuguese boys spend more time in MVPA. Girls and those with higher BMI spend more time in sedentary activities and less time in MVPA and LPA; older adolescents spend more time in sedentary activities and less time in LPA. There is a significant effect of the country of origin on MVPA, favouring Portuguese youth. Conclusions: Results suggest country differences in MVPA between Mozambican and Portuguese youth - the Mozambicans are less involved in MVPA than the Portuguese, probably reinforcing the undesirable effect of the urbanization process in developing nations.

Accelerometer-determined peak cadence and weight status in children from São Caetano do Sul, Brazil / Determinação do pico de cadência via acelerometria e estado de peso corporal em crianças de São Caetano do Sul, Brasil

Abstract The purpose of this study was to determine the relationship between peak cadence indicators and body mass index (BMI) and body fat percentage (BF%)-defined weight status in children. The sample comprised 485 Brazilian children. Minute-by-minute step data from accelerometry were rank ordered for each day to identify the peak 1-minute, 30-minute and 60-minute cadence values. Data were described by BMI-defined and bioelectrical impedance-determined BF% weight status. BMI-defined normal weight children had higher peak 1-minute (115.5 versus 110.6 and 106.6 steps/min), 30-minute (81.0 versus 77.5 and 74.0 steps/min) and 60-minute cadence (67.1 versus 63.4 and 60.7 steps/min) than overweight and obese children (p<.0001), respectively. Defined using %BF, normal weight children had higher peak 1-minute (114.5 versus 106.1 steps/min), 30-minute (80.4 versus 73.1 steps/min) and 60-minute cadence (66.5 versus 59.9 steps/min) than obese children (p<.0001). Similar relationships were observed in boys; however, only peak 1- minute cadence differed significantly across BMI and %BF-defined weight status categories in girls. Peak cadence indicators were negatively associated with BMI and BF% in these schoolchildren and significantly higher among normal weight compared to overweight or obese children.

Resumo O objetivo do estudo foi determinar a relação entre indicadores de pico de cadência com índice de massa corporal (IMC) e percentual de gordura corporal (% GC) definidos pelo estado de peso corporal de crianças. Participaram 485 crianças brasileiras. Minutos de acelerometria foram ranqueados para identificar os valores de picos de cadência de 1, 30 e 60 minutos. O estado de peso corporal foi apresentado pelo IMC e %GC, avaliados pela bioimpedância elétrica. No IMC, crianças eutróficas apresentaram maior pico de cadência de 1 minuto (115,5 versus 110,6 e 106,6 passos/min), 30 minutos (81,0 versus 77,5 e 74,0 passos/min) e 60 minutos (67,1 versus 63,4 e 60,7 passos/min) do que aqueles com excesso de peso e obesidade (p < 0,001). Na %GC, crianças eutróficas apresentaram maior pico de cadência de 1 minuto (114,5 versus 106,1 passos/min), 30 minutos (80,4 versus 73,1 passos/min) e 60 minutos (66,5 versus 59,9 passos/min) do que as obesas. Relações semelhantes foram observadas nos meninos; no entanto, apenas o pico de cadência de 1 minuto foi significativamente diferente nas categorias do estado de peso corporal definido pelo IMC e %GC nas meninas. Indicadores de pico de cadência foram negativamente associados com IMC e %GC e maior nos eutróficos do que naqueles com excesso de peso e obesidade.