Behavioral profile, lifestyle and social skills in Portuguese adolescents.

BACKGROUND: Seventy percent of premature deaths in adults are due to behaviors initiated during adolescence. Therefore, it is essential to promote individual and social behaviors that educate adolescents in the ability to make healthy choices. Accordingly, the main goals of this study were to characterize Lifestyles and Social Skills, as well as identify homogeneous subgroups, in a sample of Portuguese adolescents. METHODS: A cross-sectional study was conducted, including 1008 adolescents attending the 7th to the 9th grades of five middle schools from the Tâmega and Sousa regions of Portugal, and using the My Lifestyle Questionnaire and the Social Skills Inventory. To establish a profile of the participants, a Cluster Analysis (K-means) was performed, and the Jaccard coefficient was used to assess the stability of the solution found. RESULTS: From the total sample, 556 adolescents with a mean age of 13.43 years (SD = 1.1) were included in the analysis. The majority of the sample presented a healthy lifestyle (72.26%) and 50.7% of the adolescents had a highly elaborated repertoire of Social Skills. Moreover, three clusters were found. Cluster 1 (n = 92) showed a less elaborate repertoire of Social Skills and was designated as the "Adjusted". Cluster 2 (n = 115) comprised adolescents with a good repertoire of Social Skills and was named the "Sociable". Cluster 3 (n = 258) was composed of adolescents with a highly elaborate repertoire of Social Skills and the best Lifestyle indicators and was named the "Healthy". CONCLUSIONS: The group of adolescents in the cluster called the "Sociable" needs to be included in health education and Social Skills programs. Nutrition and Monitored Safety behaviors reveal low values and, therefore, present a greater need for awareness, sensitization, and intervention in the school context. For this reason, the promotion of a healthy lifestyle should be part of the academic curriculum and transversal to all academic disciplines.

Physical activity, sedentary time and bone tissue: effects of an 8-months interdisciplinary program with overweight/obese children / Atividade física, tempo sedentário e tecido ósseo: efeitos de um programa interdisciplinar de oito meses com crianças com sobrepeso/obesidade

Moderate to vigorous physical activity plays a recognized osteogenic effect on bone. Moreover, sedentary time, and fat accumulation are unfavorable to bone health. Our study aimed (1) to examine changes in body composition, bone tissue, physical activity, and sedentary time; and (2) to explore whether changes in physical activity intensities and in sedentary time are associated with changes in bone outcomes after a school-based interdisciplinary intervention program. A total of 53 over-weight/obese students (10.6 ± 3.5 year-olds; 26 girls) participated in physical activity classes. Bone area, bone mass, and bone mineral density z-score, body composition (fat mass, fat lean mass), phys-ical activity, sedentary time and potential confounders (vitamin D and maturational status) were assessed at baseline, and 8 months later. General Linear Models were carried out and significance level was set at 5%. Changes in moderate to vigorous physical activity were positively correlated with changes in all bone mass indicators. We observed a significant overall effect of the intervention on bone mineral density z-score changes, however after adjustments for changes in sedentary time and moderate to vigorous physical activity, no effect was observed. Finally, variations in sedentary time and in moderate to vigorous physical activity play an important role in bone mass density in those participants of the interdisciplinary program

A atividade física moderada-vigorosa tem efeito osteogênico reconhecido no osso. Além disso, o tempo sedentário e o acúmulo de gordura são desfavoráveis à saúde óssea. Este estudo objetivou: (1) examinar mudanças na composição corporal, tecido ósseo, atividade física e tempo sedentário; e (2) explorar se as mudanças nas intensidades de atividade física e no tempo sedentário estão associadas a mudanças nos resultados ósseos após um programa de intervenção interdisciplinar de base escolar. 53 estudantes com sobrepeso/obesidade (10,6 ± 3,5 anos; 26 meninas) participaram de aulas com atividade física. Área óssea, massa óssea e escore z de densidade mineral óssea, composição corporal (massa gorda, massa magra de gordura), atividade física, tempo sedentário e potenciais confundidores (vitamina D e status maturacional) foram avaliados no início e após 8 meses. Modelos Lineares Generalizados foram realizados e o nível de significância foi estabelecido em 5%. Alterações na atividade física moderada-vigorosa foram positivamente correlacionadas com as mu-danças em todos os indicadores de massa óssea. Observou-se um efeito geral significativo da intervenção nas alterações do escore z de densidade mineral óssea, entretanto, após ajustes para mudanças no tempo sedentário e atividade física moderada-vigorosa, nenhum efeito foi observado. Por fim, variações no tempo sedentário e na atividade física moderada a vigorosa desempenham importante papel na densidade da massa óssea nos participantes do programa interdisciplinar

Effect of a pilot multi-component intervention on motor performance and metabolic risks in overweight/obese youth.

This study evaluated the effect of a multi-component intervention on motor performance (MP) and metabolic risk markers (MRM) in overweight/obese youth. A secondary aim was to examine whether changes in MP are associated to changes in MRM. A 3-month multi-component intervention was performed, consisting of physical exercise sessions (twice/week;1h), nutritional education sessions (once/month), and parental support (twice/week). The sample included 35 volunteers (7-13 y.o), allocated to intervention (INT, n = 17) and control (CONT, n = 18) group. Variables were measured pre (T0) and post intervention (T1). Fasting blood samples were analyzed for MRM. MP tests included the measurement of health related physical fitness components and motor coordination performance (KTK battery). To assess food intake, a 24-hour recall diary was used. GLM-ANCOVA was performed. Standardized scores were calculated for the outcome variables, and multilinear regressions were applied to analyze associations between the key variables. INT group showed improvements in MP, glycolytic and hepatic profiles. After adjustments for MVPA, SB, total intake and maturational stage, negative associations between %ΔMP and %Δglycolytic (ß = -.424; 95%CI:-0.343:-0.022), and %Δhepatic scores (ß = -.382 95%CI:-0.001:-0.009) were observed. The intervention produced a moderate-to-high effect on the MP and some MRM. Changes in MP were inversely associated with changes in glycolytic and hepatic markers.

Physical exercise intervention at school improved hepcidin, inflammation, and iron metabolism in overweight and obese children and adolescents.

BackgroundObesity is often associated with iron deficiency in children and adolescents. We aimed to study the effect of an 8-month physical exercise (PE) intervention on hepcidin and other markers of inflammation and on iron status in overweight/obese children and adolescents.MethodsSeventy-three overweight/obese children and adolescents participated in the 8-month-long longitudinal study. They were divided into two groups according to their participation in an after-school PE program: the PE group (n=44) and the control group (n=29). Hepcidin, interleukin (IL)-6, C-reactive protein (CRP), iron, ferritin, transferrin, and soluble transferrin receptor (sTfR) were evaluated.ResultsAt baseline, IL-6 correlated positively with hepcidin and negatively with iron and transferrin saturation, suggesting that increasing adiposity associates with increasing IL-6 and hepcidin synthesis, reducing iron availability. After 8 months, the PE group showed a decrease in BMI z-score (P=0.003), body fat mass (P=0.012), CRP (P=0.002), IL-6 (P=0.048), ferritin (P=0.013), hepcidin (P=0.040), and sTfR (P=0.010), and an increase in iron concentration (P=0.002). Moreover, the PE group, when compared with the control group, showed lower weight (P=0.026), BMI (P=0.040), waist circumference (P=0.010), and waist-to-height ratio (P=0.046).ConclusionWe showed that an 8-month-long intervention at school allowed a reduction in BMI z-score and an improvement in inflammation, reducing hepcidin levels and the disturbances in iron status.

Impact of a School-Based Intervention Protocol - ACORDA Project - On Adipokines in An Overweight and Obese Pediatric Population.

PURPOSE: There are few reliable studies assessing the effect of physical exercise (PE) on adipokines levels at young ages. Our objective was to study the effects of regular PE on plasma adipokines in pediatric overweight and obesity. METHOD: 117 overweight and obese children and adolescents (47% females; 10.2 years) participated in an 8-month longitudinal study divided in two groups: PE group (n = 80), engaged in an after-school PE program; control group (n = 37), with no PE program. Plasma lipids, C-reactive protein (CRP), adiponectin, resistin, leptin, IL-6, IL-1beta, TNF-alpha, insulin and glucose levels were determined. RESULTS: contrarily to the control group, the PE group presented reductions in body mass index z-score (BMIzsc) and body fat percentage that were accompanied by an improvement in lipid profile and insulin resistance, a reduction in CRP and TNF-alpha and an increase in adiponectin levels. The reductions in BMIzsc were inversely correlated with changes in adiponectin (r=-0.329, p = .003) and positively correlated with changes in percentage body fat (r = .262, p = .032), triglycerides (r = .228, p = .042) and leptin (r = .285, p = .010). CONCLUSIONS: Moderate reductions in adiposity improve proinflammatory status in obese children and adolescents. A more substantial reduction in BMIzsc was associated with a greater increment in adiponectin and reduction in leptin.

Exercise intervention and cardiovascular risk factors in obese children. Comparison between obese youngsters taking part in a physical activity school-based programme with and without individualised diet counselling: the ACORDA project.

AIM: To determine the effects of a school-based exercise intervention programme on cardiovascular risk factors, including body fat (BF), metabolic profile and physical activity (PA) in children with and without individualised dietary counselling approach (IDC and WIDC). SUBJECTS AND METHODS: Forty-six overweight children from 6-16 years old (25 girls, 54.3%; age = 10.3 ± 2.8) of six schools took part in an 8-month interdisciplinary, school-based intervention programme. All children were engaged in PA classes, but only one group was exposed to individualised counselling. Blood pressure (BP), lipids and lipoproteins, accelerometer-based PA, percentage of body fat (%BF) and trunk fat (%TF) measures were taken before and after intervention. General Linear Model (Repeated Measures ANOVA) adjusted for age, maturation and height change was used to analyse the longitudinal effect of individualised counselling between two evaluations in each group. RESULTS: Favourable changes were observed for %BF, %TF, systolic BP and total cholesterol in the IDC group. Subjects WIDC only increased light and moderate-vigorous PA. In IDC, significant effects for time * group interactions were found for systolic BP, total cholesterol and LDL-cholesterol, indicating that counselling might add favourable changes in these markers, beyond those explained by PA and growth. CONCLUSION: School-based interventions can contribute to counteracting obesity in youth, particularly when individualised dietary counselling is provided. Therefore, the link between schools and professional counselling should be strengthened to ensure consolidated changes towards healthy behaviours.

Incidence of hypertension in schoolchildren and adolescents: relationship with physical activity, cardiorespiratory fitness and obesity / Incidência de hipertensão em crianças e adolescentes escolares: relação com a atividade física, aptidão cardiorrespiratória e obesidade / Incidencia de la hipertensión en niños y adolescentes estudiantes: relación con la actividad física, capacidad cardiorrespiratoria y obesidad

The present study examined the associations between changes over time in blood pressure (BP) with baseline and with varying levels of physical activity (PA), cardiorespiratory fitness (CRF) and body mass index (BMI). Longitudinal study, consisting of 221 young people aged between 8-17 years. The PA was assessed by questionnaire. Height was measured with a stadiometer and body mass with an electronic scale, both at school grounds. Maturacional stage was assessed through self evaluation conduced by pictures. CRF was estimated by maximal multistage 20m shuttle-run test. BP was measured with an automatic sphygmomanometer. The major results suggest that overweight / obesity, male gender and the CRF dependent of BMI are risk factors for high blood pressure in school factors.

O presente estudo verificou as associações entre as alterações ao longo do tempo dos níveis de pressão arterial (PA) com os valores basais e com a variação dos níveis de atividade física (AF), aptidão cardiorrespiratória (ApC) e índice de massa corporal (IMC). Estudo longitudinal, composto por 221 jovens com idades entre 8-17 anos. A AF foi avaliada através de questionário. A estatura foi verificada com um estadiometro e a massa corporal com uma balança eletrônica, ambos nas dependências da escola. A maturação sexual foi verificada através de auto avaliação com auxílio de imagens. A ApC foi avaliada através do teste Shuttle run-20m. A PA foi aferida com um esfigmomanômetro automático. Os principais resultados sugerem que o sobrepeso/obesidade, sexo masculino e a ApC dependente do IMC são fatores de risco de pressão arterial elevada em escolares.

Este estudio examinó las asociaciones entre los cambios en los niveles de presión arterial de tiempo (PA) con la línea de base y el cambio en los niveles de actividad física (AF), la aptitud cardiorrespiratoria (AFT) y el índice de masa corporal (IMC ). Estudio longitudinal, compuesta por 221 jóvenes de entre 8 a 17 años. La AF se evaluó mediante un cuestionario. Altura se midió con un estadiómetro y la masa corporal con una balanza electrónica, tanto en la escuela. La madurez sexual se evaluó a través de la autoevaluación con imágenes de ayuda. El AFT se evaluó mediante el traslado de pruebas previo 20m. PA se midió con un esfigmomanómetro automatizado. Los principales resultados sugieren que el sobrepeso / obesidad, masculina y dependiente AFT en el IMC son factores de riesgo de hipertensión arterial entre los escolares.

Bilirubin is independently associated with oxidized LDL levels in young obese patients.

BACKGROUND: Bilirubin can prevent lipid oxidation in vitro, but the association in vivo with oxidized low-density lipoprotein (Ox-LDL) levels has been poorly explored. Our aim is to the association of Ox-LDL with total bilirubin (TB) levels and with variables related with metabolic syndrome and inflammation, in young obese individuals. FINDINGS: 125 obese patients (13.4 years; 53.6% females) were studied. TB, lipid profile including Ox-LDL, markers of glucose metabolism, and levels of C-reactive protein (CRP) and adiponectin were determined. Anthropometric data was also collected. In all patients, Ox-LDL correlated positively with BMI, total cholesterol, LDLc, triglycerides (TG), CRP, glucose, insulin and HOMAIR; while inversely with TB and HDLc/Total cholesterol ratio (P < 0.05 for all). In multiple linear regression analysis, LDLc, TG, HDLc and TB levels were significantly associated with Ox-LDL (standardized Beta: 0.656, 0.293, -0.283, -0.164, respectively; P < 0.01 for all). After removing TG and HDLc from the analysis, HOMAIR was included in the regression model. In this new model, LDLc remained the best predictor of Ox-LDL levels (ß = 0.665, P < 0.001), followed by TB (ß = -0.202, P = 0.002) and HOMAIR (ß = 0.163, P = 0.010). CONCLUSIONS: Lower bilirubin levels may contribute to increased LDL oxidation in obese children and adolescents, predisposing to increased cardiovascular risk.

Comparison between CDC and WHO BMI z-score and their relation with metabolic risk markers in Northern Portuguese obese adolescents.

BACKGROUND: Growth-curves are an important tool for evaluating the anthropometric development in pediatrics. The different growth-curves available are based in different populations, what leads to different cut-offs. Pediatric obesity tracks into adulthood and is associated with increased cardiovascular risk. The accurate assessment of a child nutritional status using growth-curves can indicate individuals that are either obese or in risk of becoming obese, allowing an early intervention. Moreover, the association between the data obtained from growth-curves with specific metabolic risk factors further highlights the importance of these charts. This study aimed to evaluate the associations between body mass index z-score (BMIzsc), determined using the growth-curves from the Centre for Disease Control and Prevention (CDC) and from the World Health Organization (WHO), with cardiovascular risk factors, represented here by metabolic syndrome (MS) and insulin resistance (IR) related parameters. The study involved 246 obese adolescents (10-18 years, 122 females). MS was defined according to the International Diabetes Federation. IR was considered for HOMA-IR greater than 2.5. FINDINGS: No difference between both BMIzsc in identifying MS was noticeable by a ROC analysis. For both indexes the area-under-the-curve increased for older groups, particularly for males. CDC-BMIzsc was the best predictor of MS by logistic regression when all population was considered, however MS was better predicted by WHO-BMIzsc for females and by CDC-BMIzsc for males. Younger girls and older boys were in increased risk for MS. Similar results were obtained for IR. CONCLUSIONS: A significant difference between the two BMIzsc regarding their association with MS and IR was not clear, being these associations weaker in younger individuals.

Heart rate variability, adiposity, and physical activity in prepubescent children.

PURPOSE: This study aimed at examining the associations between weight status, body fat mass, and heart rate variability in prepubescent children, adjusting for physical activity levels. METHODS: A cross-sectional investigation in which a total of 50 Caucasian pre-pubertal children (21 normal weight; 8 overweight; 21 obese), aged 6-10 years (8.33 ± 1.14), including both boys (n = 24) and girls (n = 26), were recruited from local schools. Total body fat and trunk fat were evaluated through dual-energy X-ray absorptiometry. Free-living physical activity levels were evaluated by accelerometer. Short-term heart rate variability acquisition was performed; time- and frequency-domain parameters were analysed. Logarithmic transformations of the low-frequency (LnLFnu), high-frequency (LnHFnu) normalized units and low-frequency/high-frequency (LnLFnu/HFnu) ratio were computed. RESULTS: Adjusting for age, Tanner stage, and moderate to vigorous physical activity levels, obese children compared to normal weight children showed a significant decreased LnHfnu (3.8 ± 0.2 vs 4.1 ± 0.2 %) and both higher LnLFnu (4.0 ± 0.4 vs 3.7 ± 0.3 %) and LnLFnu/LnHFnu ratio (1.1 ± 0.1 vs 0.9 ± 0.1). LnHFnu showed significant negative correlation with waist circumference (r = -0.598; P = 0.000), total body fat (r = -0.409; P = 0.011) and trunk fat (r = -0.472; P = 0.003). Both LnLFnu and LnLFnu/LnHFnu ratio showed positive correlations with waist circumference (r = 0.455; r = 0.513) and trunk fat (r = 0.370; r = 0.415). CONCLUSIONS: A higher amount of body fat mass, particularly central fat, was shown to be related to decreased parasympathetic modulation in time-domain heart rate variability. This finding highlights the potential cardiovascular risk that excessive fat mass may represent even at very young age.

Physical Activity is Related to Fatty Liver Marker in Obese Youth, Independently of Central Obesity or Cardiorespiratory Fitness.

UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent complications associated with excess adiposity and has been identified as the leading cause of liver disease in pediatric populations worldwide. Because cardiorespiratory fitness (CRF) is related to physical activity (PA) levels, and increased PA plays a protective role against NAFLD risk factors, the aim of this study was to analyze the association between PA and a fatty liver marker (alanine aminotransferase - ALT) in obese children and adolescents, independently of central adiposity or CRF. 131 obese children (83 girls, 7-15 year-olds) involved in a PA promotion program comprised the sample. Measurements included anthropometric and body composition evaluations (DEXA), biological measurements (venipuncture), CRF (progressive treadmill test), PA (accelerometry), and maturational stage (Tanner criteria). The associations between ALT with PA intensities, central obesity, and CRF were calculated by three different models of linear regression, adjusted for potential confounders. Level of significance was set at 95%. RESULTS: ALT was negatively associated with MVPA (ß = -0.305), and CRF (ß = -0.426), and positively associated with central obesity (ß=.468). After adjustment for central obesity the negative and statistically significant association between ALT with MVPA (ß = -0.364) and CRF (ß = -0.550) still persists while a positive and significantly correlation was shown between ALT and SB (ß = 0.382). Additional adjustment for CRF (Model 3) showed significant associations for all the PA intensities analyzed including light activity. PA at different intensities is associated to a fatty liver marker in obese children and adolescents, independently of central adiposity or CRF. Key pointsIn a previous study our group observed that there might be a potential protective effect of cardiorespiratory fitness (CRF) against abnormal ALT values;Considering that CRF is related to physical activity (PA), and increased PA plays a protective role against fatty liver, we hypothesized that it might be an association between PA and fatty liver in obese youth, independently of central adiposity or CRF;No other study has investigated these associations in obese youth;Our findings stresses the fact that moderate-to-vigorous and light physical activities, as well as lower sedentary behavior, is associated with lower fatty liver marker, independent of the effect of potential mediators, such as central obesity or CRF.

Examining the utility of thresholds for aerobic fitness related to resting blood pressure and BMI in Portuguese children.

OBJECTIVES: This study examined the utility of the Ruiz et al. cut-points when examining body mass index (BMI) and resting blood pressure in young people. METHODS: Two hundred fifty-six children (154 girls and 102 boys) aged 7-16 years underwent assessment of BMI, physical maturation, resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) and cardiorespiratory fitness using breath by breath gas analysis during treadmill testing to exhaustion. RESULTS: Results from a series of 2 (fit vs. unfit) × 2 (gender) ways analysis of covariance, controlling for maturation indicated higher SBP in the unfit group compared to the fit group (P = 0.001), higher DBP in the unfit group compared to the fit group (P = 0.04) and higher BMI (in unfit) than fit children (P = 0.0001). Males had significantly higher BMI than females (P = 0.04). Maturation as a covariate was significantly and positively associated with SBP (P = 0.003), DBP (P = 0.004), and BMI (P = 0.001). CONCLUSIONS: This study suggests that the Ruiz et al. cut-points are valid in distinguishing between children with higher and lower BMI and resting BP values.

Body fat percentage is a major determinant of total bilirubin independently of UGT1A1*28 polymorphism in young obese.

OBJECTIVES: Bilirubin has potential antioxidant and anti-inflammatory properties. The UGT1A1*28 polymorphism (TA repeats in the promoter region) is a major determinant of bilirubin levels and recent evidence suggests that raised adiposity may also be a contributing factor. We aimed to study the interaction between UGT1A1 polymorphism, hematological and anthropometric variables with total bilirubin levels in young individuals. METHODS: 350 obese (mean age of 11.6 years; 52% females) and 79 controls (mean age of 10.5 years; 59% females) were included. Total bilirubin and C-reactive protein (CRP) plasma levels, hemogram, anthropometric data and UGT1A1 polymorphism were determined. In a subgroup of 74 obese and 40 controls body composition was analyzed by dual-energy X-ray absorptiometry. RESULTS: The UGT1A1 genotype frequencies were 49.9%, 42.7% and 7.5% for 6/6, 6/7 and 7/7 genotypes, respectively. Patients with 7/7 genotype presented the highest total bilirubin levels, followed by 6/7 and 6/6 genotypes. Compared to controls, obese patients presented higher erythrocyte count, hematocrit, hemoglobin and CRP levels, but no differences in bilirubin or in UGT1A1 genotype distribution. Body fat percentage was inversely correlated with bilirubin in obese patients but not in controls. This inverse association was observed either in 6/7 or 6/6 genotype obese patients. UGT1A1 polymorphism and body fat percentage were the main factors affecting bilirubin levels within obese patients (linear regression analysis). CONCLUSION: In obese children and adolescents, body fat composition and UGT1A1 polymorphism are independent determinants of total bilirubin levels. Obese individuals with 6/6 UGT1A1 genotype and higher body fat mass may benefit from a closer clinical follow-up.

Adiponectin and markers of metabolic syndrome in obese children and adolescents: impact of 8-mo regular physical exercise program.

BACKGROUND: Adiponectin circulates as low-, medium-, and high-molecular-weight multimers (LMW, MMW, and HMW) and influences lipid profile and insulin resistance (IR), HMW being considered as the most biologically active form. We aimed to study the relation between adiponectin and markers of metabolic syndrome (MS) in pediatric obesity, and the impact of physical exercise. METHODS: The study consisted of a cross-sectional part and an 8-mo physical exercise program. Lipid profile, insulin, glucose, C-reactive protein (CRP), total adiponectin (TA), and homeostasis model assessment IR (HOMA-IR) were measured. Adiponectin multimers were studied in a prepubertal group. RESULTS: Obesity is associated with increased dyslipidemia, IR, and inflammation. TA is correlated inversely with adiposity, triglycerides, HOMA-IR, and CRP, and positively with high-density lipoprotein cholesterol (HDLc)/total cholesterol (TC) ratio. HMW mimicked TA associations. The intervention program led to a reduction of TC, low-density lipoprotein cholesterol (LDLc), insulin, HOMA-IR, and trunk percentage of fat, and an increase of HDLc/TC ratio, in the obese group. BMI improvements prevented adiponectin reduction and correlated with increments in HMW and MMW. CONCLUSION: Obesity-related increase in MS features might be linked to lower adiponectin. HMW and MMW were the multimers that most explained the MS features. The intervention program improved the lipid profile and IR, and prevented the reduction of adiponectin.

Barriers and facilitators to the promotion of healthy eating lifestyles among adolescents at school: the views of school health coordinators.

This study evaluates the perceptions of teachers in charge of coordinating health education in schools: the School Health Coordinators (SHCs). It addresses the success and barriers of the development and implementation regarding the first year of healthy eating programmes in their schools. This research is based on 16 face-to-face semi-structured interviews with SHCs from Portuguese public schools offering from fifth to ninth grades. A thematic analysis was performed and themes were identified, taking into consideration similarities and differences among the participants' opinions. The results showed that the schools in this study often involved a set of separate healthy diet promotion activities with a low level of joint effort from all members of the school. Nevertheless, in Portugal, health education is based on the broad concept that school health promotion is compulsory for all schools. Two main barriers were identified in order to explain this divergence: structural and political idiosyncrasies among schools and the food environment inside and outside the schools. The results are discussed considering the wide range of factors influencing young people's eating behaviours and recommendations are made for the different agents interacting with them in order to promote appropriate eating habits.

Associations between sports participation, levels of moderate to vigorous physical activity and cardiorespiratory fitness in childrenand adolescents.

The purpose of this study was to analyse the associations between sports participation, levels of moderate to vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF). The study comprised 310 participants (183 girls and 127 boys) aged 11-18 years. Sports participation was assessed by questionnaire and habitual physical activity (PA) was measured objectively with accelerometers. The 20-m shuttle-run test was used to estimate CRF. Logistic regression analyses were carried out with CRF as the outcome. The odds ratio (OR) for being fit was greater for those who comply with 60 min · day(-1) in MVPA (OR = 2.612; 95%confidence interval [CI] = 1.614-4.225) in comparison with those who do not. Participation in competitive sports at club levels increased the chances of being fit (OR = 13.483; 95%CI = 4.560-39.864), independently of MVPA levels. There were positive and significant trends in CRF and objectively measured PA across the levels of engagement in competitive sports (P < 0.05). Concluding, participation in competitive sports at club level is more effective than other organised or non-organised sports to reach healthier levels of CRF and recommend levels of MVPA.

Cardiorespiratory fitness, but not central obesity or C-reactive protein, is related to liver function in obese children.

UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent complications associated with excess adiposity. Its pathogenesis is complex and there are multiple factors that may contribute to it. AIM: To analyze whether cardiorespiratory fitness (CRF), waist circumference (WC), and C-reactive protein (CRP) are associated with alanine aminotransferase (ALT) in children with obesity. METHODS: 79 overweight/obese children of both genders, 11-13 year-olds, with abnormal serum ALT from Porto public schools comprised the sample. Measurements included CRF (20-m Shuttle Run Test), WC (NHANES protocol), CRP and ALT (Cholestech LDX analyzer). Logistic regression adjusted for gender, maturation, and weight with ALT levels as dependent variable (risk vs. non risk), and WC (risk vs. non risk), CRP (risk vs. non risk), and CRF (fit vs. unfit) as independent variables. Level of significance was set at 95%. RESULTS: Logistic regression showed that obese fit children were less likely to have abnormal ALT values (OR=.031) CONCLUSION: In obese children, higher cardiovascular fitness appears to reduce the chance of decreased liver function.

Fitness and metabolic syndrome in obese fatty liver children.

BACKGROUND: Metabolic Syndrome (MS) is highly prevalent among obese children with fatty liver. However, it is well-known that there is a lower prevalence of MS in individuals with higher cardiorespiratory fitness (CRF). AIM: To analyse the association between CRF with features of the MS in obese children that present fat liver indicators, namely abnormal alanine aminotransferase (ALT) values. METHODS: A total of 79 obese students (40 girls), 10-11 year-olds ( ± 0.60), with abnormal serum ALT from Porto public schools comprised the sample. Measurements included CRF (20-metre Shuttle Run Test), Metabolic Risk Factors (MRF), according to MS International Diabetes Federation criteria, ALT values (Cholestech LDX(®) analyser) and maturational stage (Tanner criteria). Logistic regression analysis was used to determine the influence of CRF on MRF adjusted for sex, maturation, and BMI. RESULTS: The logistic regression showed that, despite being classified as being obese and presenting abnormal levels of ALT, those classified as fit were less likely to have MS than their unfit counterparts (OR = 0.52; p ≤ 0.05). CONCLUSION: Obese-fit children with abnormal ALT values have a significant reduction in the likelihood to be classified as having MS, even after adjustments for gender, maturation and BMI, Thus, CRF might be an important factor for tackling fatty liver among obese.

Normative and criterion-related standards for shuttle run performance in youth.

The purpose of this study was to calculate and validate reference standards for the 20-m shuttle run test (SR) in youths aged 10-18 years. Reference standards based on the number of completed SR laps were calculated by LMS method in a reference group of 5559 students. Cut-off values for SR laps were determined and tested by ROC curve analysis in a validation group (633 students), from which waist circumference, HDL-cholesterol, triglycerides, fasting glucose and mean arterial pressure were assessed to calculate a metabolic risk score, later dichotomized in low and high metabolic risk (HMRS). The accuracy of SR laps standards was significant for girls (AUC = 0.66; 95% CI = 0.58-0.74; p < .001) and boys (AUC = 0.71; 95% CI = 0.62-0.79; p < .001) for identifying subjects at HMRS. The 40th percentile was the best cut-off for SR laps in girls (SENS = 0.569; 1-SPEC = 0.330) and boys (SENS = 0.634; 1-SPEC = 0.266). New SR laps reference standards are able to discriminate metabolic risk levels, and may provide a valuable tool for early prevention of cardiovascular risk factors.

Associations between self-rated health with cardiorespiratory fitness and obesity status among adolescent girls.

BACKGROUND: The main goal of this study was to analyze the associations between cardiorespiratory fitness (CRF) and body mass index (BMI) with self-rated health (SRH) of adolescent girls. METHODS: This was a cross-sectional study of 533 adolescents girls, aged from 10 to 18 years old. CRF was predicted by maximal multistage 20-m shuttle-run test according to procedures described from FITNESSGRAM. Girls' obesity status was classified according to International Obesity Task Force and Self-rated health (SRH) was assessed by questionnaire. RESULTS: The findings showed that among adolescent girls 23.2% had negative SRH. Girls who were classified as unfit were more likely to report negative SRH in both univariate logistic (OR: 3.05; CI: 1.91-4.87; P < .05) and multivariate (OR: 2.93; CI: 1.82-4.72; P < .05) regression analyses compared with their fit peers. Obese girls were more likely to report negative SRH (OR: 2.30; CI: 1.14-4.62; P < .05) compared with their normal-weight counterparts. However such association was lost in multivariate analyses suggesting an effect of CRF. CONCLUSIONS: Negative perception of health was associated with lower CRF and weight status although such association it is mediated by CRF condition.