ObjectiveEarly detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals’ health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese.DesignCross-sectional study.Setting23 primary schools and 17 secondary schools from Spain.Participants2198 students (1060 girls), grades 1–4 and 7–10.MeasuresPubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated.ResultsNC was positively correlated with all anthropometric and body composition indices. NC was negatively associated with maximum oxygen consumption (R2=0.231, p<0.001 for boys; R2=0.018, p<0.001 for girls) and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin, adiponectin and clustered CVD risk factor in both sexes (R2 from 0.035 to 0.353, p<0.01 for boys; R2 from 0.024 to 0.215, p<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein, LDL-c and visfatin only in boys (R2 from 0.013 to 0.107, p<0.05).ConclusionNC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided.

Physical fitness was negatively associated with single and clustered inflammatory biomarkers, independently of body mass index. Increasing physical fitness levels in youth might contribute to reduce the cardiovascular risk.

The present study examined the association between high-quality diet (using the Mediterranean diet (MD) as an example) and well-being cross-sectionally and prospectively in Spanish children and adolescents. Participants included 533 children and 987 adolescents at baseline and 527 children and 798 adolescents at 2-year follow-up, included in the UP&DOWN study (follow-up in schoolchildren and adolescents with and without Down’s syndrome). The present study excluded participants with Down’s syndrome. Adherence to an MD was assessed using the KIDMED index. Well-being was measured using the Positive and Negative Affect Schedule and the KIDSCREEN-10 questionnaire. Associations between MD adherence and well-being were assessed using multi-level, mixed-effects linear regression. At baseline, MD adherence was positively related to health-related quality of life in secondary school girls and boys (β=0·41, se 0·10, P<0·001; β=0·46, se 0·10, P<0·001, respectively) and to positive affect in secondary school girls and boys (β=0·16, se 0·05, P=0·006; β=0·20, se 0·05, P<0·001, respectively) and in primary school boys (β=0·20, se 0·08, P=0·019). At 2-year follow-up, MD adherence was negatively related to negative affect in secondary school adolescent girls and boys (β=–0·15, se 0·07, P=0·047; β=–0·16, se 0·06, P=0·019, respectively), and MD adherence was associated with higher positive affect scores in secondary school girls (β=0·30, se 0·06, P<0·001) and in primary school boys (β=0·20, se 0·09, P=0·023). However, MD adherence at baseline did not predict well-being indicators at 2-year follow-up. In conclusion, higher MD adherence was found to behave as a protective factor for positive well-being in cross-sectional analysis.

Time spent at different physical activity intensities during PE and recess does not impair academic performance in youth.

Background: Longitudinal changes in child and adolescent active school transport (AST), and the mediating role of different intensities of daily physical activity (PA) levels in relation to AST and physical fitness and adiposity indicators is unclear. This study aimed to: 1) describe longitudinal changes in AST, light PA (LPA), moderate-to vigorous-intensity PA (MVPA), physical fitness and adiposity indicators over three time-points; and 2) investigate the mediating role of LPA and MVPA levels on associations between AST and physical fitness and adiposity indicators over three time-points among children and adolescents. Methods: This longitudinal study comprised 1646 Spanish children and adolescents (48.8% girls, mean age 12.5 years ±2.5) at baseline, recruited from schools in Cádiz and Madrid. Mode of commuting to school was selfreported at baseline (T0, 2011-12), 1-year (T1) and 2-year follow-up (T2). PA was assessed using accelerometers. Handgrip strength, standing long jump and cardiorespiratory fitness (CRF) assessed physical fitness. Height, weight, body mass index, waist circumference, and triceps and subscapular skinfold thickness were measured. Multilevel linear regression analyses assessed changes in AST, PA levels, physical fitness and adiposity indicators over three time-points (T0-T1-T2). Additionally, longitudinal path analysis (n = 453; mean age [years] 12.6 ± 2.4) was used to test the mediating effects of LPA and MVPA levels on the association between AST and physical fitness and adiposity indicators.