Cardiorespiratory fitness has declined among French children since 1999, although the decline appears to be getting smaller.

BACKGROUND: Cardiorespiratory fitness (CRF) is a strong marker of current and future health. The aim of this study was to assess the national temporal trends in CRF for French children and adolescents between 1999 and 2022. METHODS: CRF data were obtained from several cross-sectional studies on 15 420 (51.1% boys) French children and adolescents aged 9-16 years between 1999 and 2022. The 20-m shuttle run test (20mSRT) estimated CRF. Body mass index (BMI) was calculated from measured height and body mass, with BMI z-scores (BMIz) calculated using WHO growth curves. The 20mSRT results were corrected for protocol and converted to z-scores (20mSRTz) using international sex- and age-specific norms. With additional adjustment for BMIz, temporal trends in mean 20mSRT performance (20mSRTz) were estimated using linear regression, with the distance max (Dmax) method used to locate a breakpoint and linear segments fitted to points below and above the breakpoint. Trends in distributional characteristics were assessed visually and described as the ratio of the coefficients of variation (CVs). RESULTS: After adjustment for protocol, age, sex, and BMIz, a large decline in mean 20mSRT performance (trend per decade (95% CI): -1.42 SDs (-1.45, -1.39) or -18.4% (95% CI: -18.8, -18.0)) between 1999 and 2022 was found. Dmax located a breakpoint for the two-linear-segment model in year 2010. There was a large decline in mean 20mSRT performance pre-2010 (trend per decade (95% CI): -2.31 SDs (-2.39, -2.24)), which reduced 0.06-fold to a negligible decline post-2010 (trend per decade (95% CI): -0.15 SD (-0.20, -0.10)). We also found that the trend in mean 20mSRT performance was not uniform across the population distribution. Between 1999 and 2022, there was a small trend in distributional asymmetry, with slightly smaller declines experienced by the high performers (above the 75th percentile). CONCLUSIONS: Our data suggest a large decline in the 20mSRT performance of French children and adolescents since 1999. This declining trend seems to have diminished considerably since 2010. Such declines in CRF could translate into declines in health status. Although a slowing in the declining trend in CRF in recent years is encouraging, more data are needed to confirm these findings.

Clinical and physical characteristics of thinness in adolescents: the HELENA study.

PURPOSE: Thinness in adolescence has not been studied as extensively as overweight or obesity. The aim of this study was to assess the prevalence, characteristics, and health impacts of thinness in a European adolescent population. METHODS: This study included 2711 adolescents (1479 girls, 1232 boys). Blood pressure, physical fitness, sedentary behaviors, physical activity (PA), and dietary intake were assessed. A medical questionnaire was used to report any associated diseases. A blood sample was collected in a subgroup of the population. Thinness and normal weight were identified using the IOTF scale. Thin adolescents were compared with adolescents of normal weight. RESULTS: Two hundred and fourteen adolescents (7.9%) were classified as being thin; the prevalence rates were 8.6% in girls and 7.1% in boys. Systolic blood pressure was significantly lower in adolescents with thinness. The age at the first menstrual cycle was significantly later in thin female adolescents than in those with normal weight. Upper-body muscular strength measured in performance tests and time spent in light PA were significantly lower in thin adolescents. The Diet Quality Index was not significantly lower in thin adolescents, but the percentage of adolescents who skipped breakfast was higher in adolescents with a normal weight (27.7% vs 17.1%). Serum creatinine level and HOMA-insulin resistance were lower and vitamin B12 level was higher in thin adolescents. CONCLUSIONS: Thinness affects a notable proportion of European adolescents with no physical adverse health consequences.

Validation of the IMPACT-III Questionnaire in French Children With Inflammatory Bowel Disease.

OBJECTIVES: This study assessed the reliability and validity of the IMPACT-III questionnaire, a health-related quality of life (HRQoL) instrument, in French children with inflammatory bowel disease (IBD). METHODS: Eighty-four children and adolescents (45 boys, aged 14.3 ± 2.7 years) were included in a validation study of the IMPACT-III questionnaire. Patients completed 2 questionnaires for measuring HRQoL: the IMPACT-III and the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL). Internal consistency was assessed using Cronbach α. Factor analysis was performed on data from the IMPACT-III to help construct domains. Concurrent validity was assessed by calculating Spearman correlation coefficients. RESULTS: Cronbach α for the PedsQL total score was good (0.89). The most robust factor solution was a 3-domain structure: (a) Concerns, (b) Body Image and Physical Condition, and (c) Symptoms and Socializing. All domains had good reliability (0.674-0.863). Only 2 items had to be removed. Discriminant validity was demonstrated by significant differences ( P < 0.001) in median IMPACT-III scores between inactive and active disease for the total score (83.3 vs 72.0), and for Concerns ( P < 0.002) and Symptoms and Socializing ( P < 0.001). CONCLUSIONS: These results suggest that IMPACT-III appears to be a useful instrument for measuring HRQoL in French children with IBD.

Changes in physical activity patterns from adolescence to young adulthood: the BELINDA study.

Physical activity (PA) is recognized as a marker of health. The aim was to investigate PA differences from adolescence to young adulthood. European adolescents included in the HELENA study were invited to participate in a follow-up study, 10 years later. The present study included 141 adults (25.0 ± 1.4 years) for whom valid accelerometer data were available in adolescence and adulthood. Changes in PA by sex, weight and maternal education level were explored with interactions. Time spent in sedentary activity, light PA (LPA) and moderate PA (MPA) increased by 39.1, 59.6 and 6.6 min/day, respectively, whereas the time spent in vigorous PA (VPA) decreased by 11.3 min/day compared with adolescent VPA (p < 0.05). Increases in MPA were greater on weekends compared with weekdays, but we found a greater decrease in VPA on weekdays compared with weekends. Moderate-to-vigorous PA (MVPA) decreased significantly on weekdays (-9.6 min/day; 95%CI, -15.9 to -3.4), while it increased on weekends (8.4 min/day; 95%CI, 1.9 to 14.8). Significant heterogeneity was found across sexes for VPA and MVPA, with a stronger decrease in VPA in males compared with females and a significant decrease in MVPA (-12.5 min/day; 95%CI, -20.4 to -4.5) in males but not in females (1.9 min/day; 95%CI, -5.5 to 9.2). No significant heterogeneity was found to be linked to maternal education level or weight, irrespective of PA level.  Conclusion: Our data suggest that the transition from adolescence to young adulthood is a critical period for lifestyle PA habits. A decline in VPA and an increasingly sedentary time were observed. The observed changes are worrying and may increase the risk of developing adverse health consequences later in life. What is Known: • The transition from adolescence to adulthood is marked by many life changes affecting lifestyle habits. Most studies tracking physical activity from adolescence to adulthood were done using PA questionnaires, which is a subjective method. What is New: • Our study bring first data on objective changes in PA patterns between adolescence and young adulthood, taking account of BMI, sex and maternal educational level. Our results suggest that the transition from adolescence to young adulthood is a critical period for lifestyle PA habits, especially for time spent on sedentary activities.

European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network.

OBJECTIVES: (1) To develop reference values for health-related fitness in European children and adolescents aged 6-18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. METHODS: This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test-retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. RESULTS: A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). CONCLUSION: This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe.

Evaluation of Physical Activity Indicators for French Children and Adolescents With Disabilities: National Para Report Card and SWOT Analysis.

The objectives of this work were (a) to adopt the Active Healthy Kids Global Alliance Report Card methodology to evaluate the state of physical activity (PA) for French children and adolescents with disabilities (CAWD) and (b) to identify the strengths, weaknesses, opportunities, and threats (SWOT) perceived by French PA experts for promoting PA among CAWD. The harmonized Active Healthy Kids Global Alliance Report Card development process was used to assign a grade to the 10 common PA indicators. SWOT templates were completed by PA experts and then collapsed in a summary figure. Despite increasing efforts to provide active opportunities to CAWD, concerning low grades were assigned to behavioral indicators. SWOT analysis provided important insights for the promotion of PA in CAWD. This work highlighted the need for the inclusion of CAWD in a comprehensive national PA surveillance system and for more efficient strategies promoting PA specifically targeting CAWD in France.

Change in physical fitness due to the COVID-19 pandemic lockdown in French adolescents: a comparison between two independent large samples from Diagnoform battery.

Numerous studies reported a significant decline in physical activity level in adolescents as a result of the COVID-19 lockdown. Physical fitness is recognized as a powerful marker of health in youth. The aim of this study was to evaluate the impact of the COVID-19 pandemic lockdown on health-related physical fitness in French adolescents. Two cross-sectional studies were performed comparing two different groups of French adolescents, before (sample 1) and after the first lockdown (sample 2). A total of 1231 adolescents (aged to 16.5 ± 1.5 years) participated in the two cross-sectional studies. Complete data for physical fitness and anthropometrics data were obtained. Adolescents from sample 2 showed lower physical fitness levels compared to adolescents from sample 1. Regarding physical fitness for boys and girls, physical fitness levels were significantly lower in both sex between adolescents from the sample 1 and adolescents from the sample 2, except for cardiorespiratory fitness and flexibility for boys and girls, respectively. The physical fitness global score was also significantly lower between adolescents from the sample 1 and 2 for boys (-9.8%, p < 0.01) and girls (-16.2%; p < 0.01), respectively. Overall, the higher difference was found for performance in the speed body displacement test (-30%). A difference of 12.8% and 25% was observed for boys and girls, respectively.   Conclusion: COVID-19 pandemic lockdown had a negative impact on physical fitness in French youth. This study highlights the need to develop, in a near future, prevention programmes in order to improve the physical fitness in youth. What is Known: • COVID-19 pandemic deeply impacted lifestyle habits. A worrying decrease of physical activity, associated to a dramatic increase of time spent in sedentary behaviors was found in many coutries. What is New: • Our study bring first data on the health-related physical fitness consequences due to lockdown in French adolescents. Our study demonstrate the negative impact of COVID-19 pandemic lockdown on health-related physical fitness in French adolescents.

Daily physical activity patterns in children and adolescents with inflammatory bowel disease.

BACKGROUND: The aim of this study was to assess PA patterns among children and adolescents with inflammatory bowel disease (IBD). METHODS: Sixty participants with IBD (42 Crohn's disease [CD], 10 ulcerative colitis [UC], and 8 IBD-unclassified [IBD-U], 30 male patients) in remission (n = 45) or with mild disease (n = 15) were compared with 60 healthy age- and sex-matched controls. Each participant wore a triaxial accelerometer during 4 consecutive days for objective daily PA quantification. RESULTS: Overall, there was no significant difference in daily PA patterns between patients with IBD and healthy controls, with 31.7% of patients with IBD and 38.3% of healthy controls fulfilling the recommendation of 60 min of moderate-to-vigorous physical activity (MVPA) daily (NS). Male patients with IBD spent significantly less time in MVPA compared with matched healthy controls (mean difference, 16.2 min day-1; p < 0.05). No difference was observed for female patients with IBD. No difference in sedentary pattern between male patients with IBD and controls was found. CONCLUSIONS: Children and adolescents with inactive or mildly active IBD have similar PA patterns compared with healthy controls, except for male patients who have reduced moderate-to-vigorous PA. By far, most patients with IBD do not fulfill the MVPA recommendations for health benefits. IMPACT: There is few data on PA patterns in pediatric patients with IBD. Methodological issues to assess PA limit the strengths of these studies. Pediatric IBD patients with inactive or mildly active IBD have similar physical activity patterns compared with healthy controls, except for male patients who have reduced moderate-to-vigorous PA. Most patients with IBD do not fulfill the MVPA recommendations for health benefits.

School time is associated with cardiorespiratory fitness in adolescents: The HELENA study.

We assessed the association between school time and physical fitness in adolescents. The study included 2,024 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Health-related physical fitness components were assessed using the physical fitness tests battery. Cardiovascular risk was categorized using the sex-specific cut-offs for a healthy cardiorespiratory fitness level in adolescents proposed by FitnessGram®. School time was classified as short or long. Multivariate analysis accounted for confounding factors such age, sex, body mass index, time spent in moderate to vigorous physical activity, pubertal status, and parents' educational level. Cardiorespiratory fitness was higher in adolescents with a long school time than in those with a short school time (42.0 ± 7.6 vs 40.7 ± 7.2 mL.kg-1.min-1, respectively; p < 0.05). The percentage of adolescents at cardiovascular risk in adulthood was higher in the short than in the long time group (45.2% vs 31.7%, respectively) (p < 0.05). These findings suggest that a long school day is associated with higher cardiorespiratory fitness in adolescents and that school time should be considered in interventions and health promotion strategies.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents.

BACKGROUND: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. METHODS: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries. RESULTS: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. CONCLUSIONS: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Trends in the prevalence of overweight, obesity and underweight in French children, aged 4-12 years, from 2013 to 2017.

OBJECTIVE: To assess the prevalence of underweight, overweight and obesity in French children from 2013 to 2017. DESIGN: Cross-sectional study performed in fourteen regions of France. Physical measures included weight, height and BMI. Underweight, overweight and obesity were defined according to age- and sex-specific BMI cut-off points from the International Obesity Task Force. SETTING: France. SUBJECTS: Children (10 159 boys, 9757 girls) from the voluntary, non-representative Diagnoform programme between 2013 and 2017, at the age of 4-12 years. RESULTS: The prevalence of overweight and obesity was higher in girls compared with boys (P < 0·001). Underweight was also more prevalent in girls (P < 0·05). Although there were no significant changes in the prevalence of obesity in boys or girls from 2013 to 2017, a significant decrease in overweight among boys and girls was found (P < 0·001) during the same time period. In contrast, the prevalence of underweight increased in girls and boys (from 10·0 to 20·0 %, P < 0·0001) between 2013 and 2017. CONCLUSIONS: Results of the current study show that the prevalence of obesity was stable, while the prevalence of overweight decreased significantly, despite high in French children. Findings suggest also that thinness is becoming an important phenomenon in children. Developing preventive and nutritional programmes in order to modify the lifestyle might help control underweight and obesity in children.

Normative health-related fitness values for French children: The Diagnoform Programme.

The primary objective of this study was to establish sex- and age-specific physical fitness percentiles for French children. The secondary aim was to assess sex, weight status, and age differences for physical fitness levels in French children. A sample of 31 484 children (16 023 boys, 15 461 girls) aged 6-11 years participated in the Diagnoform programme. Cardiorespiratory fitness, muscular endurance, speed, flexibility, and agility were assessed in this national programme. Percentile values were estimated as a function of age stratified by sex using a parametric method providing smooth centile curves and explicit formulae for the centile estimates. Values from the 10th to the 90th percentile are reported. The influence of body weight according to sex on the physical fitness level was also examined using an analysis of covariance adjusted for age. Physical fitness levels were slightly better in boys, except for agility and flexibility, in which girls performed better (Cohen's coefficient, 0.20-0.45; P < .001). All physical fitness tests were significantly associated with age (P < .0001). In general, overweight and obese children had a significantly poorer physical fitness level compared with their normal-weight counterparts (P < .05). No difference was found between thin and normal-weight boys and girls, except for agility (P < .05). Reference values provide normative data for French children, and these data should be useful for identifying special needs for appropriate intervention programmes.

Comparison and validation of accelerometer wear time and non-wear time algorithms for assessing physical activity levels in children and adolescents.

BACKGROUND: Accelerometers are widely used to measure sedentary time and daily physical activity (PA). However, data collection and processing criteria, such as non-wear time rules might affect the assessment of total PA and sedentary time and the associations with health variables. The study aimed to investigate whether the choice of different non-wear time definitions would affect the outcomes of PA levels in youth. METHODS: Seventy-seven healthy youngsters (44 boys), aged 10-17 years, wore an accelerometer and kept a non-wear log diary during 4 consecutives days. We compared 7 published algorithms (10, 15, 20, 30, 60 min of continuous zeros, Choi, and Troiano algorithms). Agreements of each algorithm with the log diary method were assessed using Bland-Altmans plots and by calculating the concordance correlation coefficient for repeated measures. RESULTS: Variations in time spent in sedentary and moderate to vigorous PA (MVPA) were 30 and 3.7%. Compared with the log diary method, greater discrepancies were found for the algorithm 10 min (p < 0.001). For the time assessed in sedentary, the agreement with diary was excellent for the 4 algorithms (Choi, r = 0.79; Troiano, r = 0.81; 30 min, r = 0.79; 60 min, r = 0.81). Concordance for each method was excellent for the assessment of time spent in MVPA (> 0.86). The agreement for the wear time assessment was excellent for 5 algorithms (Choi r = 0.79; Troiano r = 0.79; 20 min r = 0.77; 30 min r = 0.80; 60 min r = 0.80). CONCLUSIONS: The choice of non-wear time rules may considerably affect the sedentary time assessment in youth. Using of appropriate data reduction decision in youth is needed to limit differences in associations between health outcomes and sedentary behaviors and may improve comparability for future studies. Based on our results, we recommend the use of the algorithm of 30 min of continuous zeros for defining non-wear time to improve the accuracy in assessing PA levels in youth. TRIAL REGISTRATION: NCT02844101 (retrospectively registered at July 13th 2016).

Adolescents' diet quality in relation to their relatives' and peers' diet engagement and encouragement: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study.

OBJECTIVE: To examine the associations between adolescents' diet quality and their perceived relatives' and peers' diet engagement and encouragement. DESIGN: Cross-sectional study performed in European countries. Diet quality was scored using the Diet Quality Index for Adolescents (DQI-A) based on four components: quality, diversity, balance and meal frequency. Perceived diet quality engagement and perceived encouragement of the relatives/peers were assessed using the questions 'How healthy is each of the following persons' diet?' and 'How often does each of the following persons encourage you to eat a healthy diet?' SETTING: Vienna, Ghent, Lille, Athens, Heraklion, Pecs, Rome, Dortmund, Zaragoza and Stockholm. SUBJECTS: Healthy adolescents (n 2943). RESULTS: The perceived engagement level of the mother, father and sister was each positively associated with the DQI-A (P<0·05). A positive association was found for the perceived engagement level of siblings, father and mother with all specific components (P<0·05). DQI-A was negatively associated with the perceived encouragement level from a best friend and positively associated with the encouragement level of the mother and father (P<0·05). Diversity, balance and quality components were positively associated with the perceived encouragement level from the mother and father (P<0·05), whereas the best friend's perceived encouragement was negatively associated with the meal frequency component (P<0·01). CONCLUSIONS: These findings highlight the role of social engagement and encouragement of relatives and peers in adolescents' diet quality. Intervention or promotion programmes aimed at enhancing diet quality in adolescents should target both family and peers.

Physical activity awareness of European adolescents: The HELENA study.

The aim of this study was to assess physical activity (PA) awareness of adolescents and to identify anthropometric and psychosocial factors that can lead to under or overestimation of PA. This study included 2044 adolescents. Participants wore a uniaxial accelerometer for 7 days to measure PA and completed a self-rated questionnaire about PA. Adolescents were classified into four PA awareness subgroups (realistically active, overestimators, underestimators and realistically inactive) according to the self-rated and objective assessment of PA. Characteristics and psychosocial factors of the self-rated physically active groups were compared using bivariate and multivariate mixed logistic regression models. Forty-five percent of adolescents reported their PA levels correctly (34.8% realistically active and 10.1% realistically inactive). Among the 59.4% who were objectively inactive, 82.9% tended to overestimate their PA level. Adolescents who overestimated their PA level were older (P < .05), had more support from mother and a best friend (P < .05) and had higher cardiorespiratory fitness (P < .001) compared with those who were realistically active. A significant number of adolescents believe that they are physically active when they are not. Improving awareness, especially in the high-risk groups identified here, might help to bring about behavioural changes in physically inactive adolescents.

Early life programming of attention capacity in adolescents: The HELENA study.

The study aims to examine the individual and combined association of early life factors (birth weight, birth length, and any and exclusive breastfeeding) with attention capacity in adolescents. The study included 421 European adolescents (243 girls), aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Body weight and length at birth of adolescents were collected from parental records. The duration of any and exclusive breastfeeding were self-reported. The d2 Test of Attention was administered to assess attention capacity. The main results showed that birth weight, birth length, breastfeeding, and exclusive breastfeeding were related to attention capacity in boys (ß ranging from 0.144 to 0.196; all p < .05) after adjustment for age, centre, gestational age, maternal education, family affluence scale, and body mass index. Among boys, differences in attention capacity were found according to tertiles of birth weight and birth length (p < .05), as well as borderline significant differences across groups of any and exclusive breastfeeding (p = 0.055 and p = 0.108, respectively) after adjusting for potential confounders. In addition, boys with 3 early life risk factors (low birth weight, low birth length, and <3 months of breastfeeding) had significantly lower scores in attention capacity compared with boys with 0 risk factors (percentile score - 15.88; p = 0.009). In conclusion, early life factors, both separately and combined, may influence attention capacity in male European adolescents. Importantly, the combination of the 3 early life risk factors, low birth weight, low birth length, and <3 months of breastfeeding, even in normal ranges, may provide the highest reduction in attention capacity.

Amino acids intake and physical fitness among adolescents.

The aim was to investigate whether there was an association between amino acid (AA) intake and physical fitness and if so, to assess whether this association was independent of carbohydrates intake. European adolescents (n = 1481, 12.5-17.5 years) were measured. Intake was assessed via two non-consecutive 24-h dietary recalls. Lower and upper limbs muscular fitness was assessed by standing long jump and handgrip strength tests, respectively. Cardiorespiratory fitness was assessed by the 20-m shuttle run test. Physical activity was objectively measured. Socioeconomic status was obtained via questionnaires. Lower limbs muscular fitness seems to be positively associated with tryptophan, histidine and methionine intake in boys, regardless of centre, age, socioeconomic status, physical activity and total energy intake (model 1). However, these associations disappeared once carbohydrates intake was controlled for (model 2). In girls, only proline intake seems to be positively associated with lower limbs muscular fitness (model 2) while cardiorespiratory fitness seems to be positively associated with leucine (model 1) and proline intake (models 1 and 2). None of the observed significant associations remained significant once multiple testing was controlled for. In conclusion, we failed to detect any associations between any of the evaluated AAs and physical fitness after taking into account the effect of multiple testing.

Diet quality and attention capacity in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study.

Adolescence represents an important period for the development of executive functions, which are a set of important cognitive processes including attentional control. However, very little is known regarding the associations of nutrition with components of executive functions in adolescence. Thus, the aim of this study was to investigate associations of dietary patterns and macronutrient composition with attention capacity in European adolescents. This cross-sectional study included 384 (165 boys and 219 girls) adolescents, aged 12·5-17·5 years, from five European countries in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Attention capacity was examined using the d2 Test of Attention. Dietary intake was assessed through two non-consecutive 24 h recalls using a computer-based self-administered tool. Three dietary patterns (diet quality index, ideal diet score and Mediterranean diet score) and macronutrient/fibre intakes were calculated. Linear regression analysis was conducted adjusting for age, sex, BMI, maternal education, family affluence scale, study centre and energy intake (only for Mediterranean diet score). In these adjusted regression analyses, higher diet quality index for adolescents and ideal diet score were associated with a higher attention capacity (standardised ß=0·16, P=0·002 and ß=0·15, P=0·005, respectively). Conversely, Mediterranean diet score or macronutrient/fibre intake were not associated with attention capacity (P>0·05). Our results suggest that healthier dietary patterns, as indicated by higher diet quality index and ideal diet score, were associated with attention capacity in adolescence. Intervention studies investigating a causal relationship between diet quality and attention are warranted.

Awareness of wearing an accelerometer does not affect physical activity in youth.

BACKGROUND: This study aimed to investigate whether awareness of being monitored by an accelerometer has an effect on physical activity in young people. METHODS: Eighty healthy participants aged 10-18 years were randomized between blinded and nonblinded groups. The blinded participants were informed that we were testing the reliability of a new device for body posture assessment and these participants did not receive any information about physical activity. In contrast, the nonblinded participants were informed that the device was an accelerometer that assessed physical activity levels and patterns. The participants were instructed to wear the accelerometer for 4 consecutive days (2 school days and 2 school-free days). RESULTS: Missing data led to the exclusion of 2 participants assigned to the blinded group. When data from the blinded group were compared with these from the nonblinded group, no differences were found in the duration of any of the following items: (i) wearing the accelerometer, (ii) total physical activity, (iii) sedentary activity, and (iv) moderate-to-vigorous activity. CONCLUSIONS: Our study shows that the awareness of wearing an accelerometer has no influence on physical activity patterns in young people. This study improves the understanding of physical activity assessment and underlines the objectivity of this method. TRIAL REGISTRATION: NCT02844101 (retrospectively registered at July 13th 2016).

Attention capacity in European adolescents: role of different health-related factors. The HELENA study.

We compared the level of attention capacity between adolescents from the center and south of Europe. The study included 627 European adolescents (54% girls), aged 12.5-17.5 years, who participated in the HELENA Study. The d2 Test of Attention was administered to assess attention capacity. The main results showed that adolescents from the south of Europe had significantly higher score in attention capacity compared with adolescents from central Europe (score + 8.1; 95%CI, 2.44-13.61) after adjustment for age, sex, socioeconomic indicators, body mass index, cardiorespiratory fitness and diet quality index (p = 0.012). CONCLUSION: Adolescents from the south of Europe had higher levels of attention capacity than their counterparts from central Europe independently of sociodemographic and health-related factors. These differences should be taken into account by educational institutions when promoting new approaches for putting into the practice student's capacities. What is Known? • Attention is a crucial capacity during adolescence. • Several health-related factors (i.e., physical activity, fitness or fatness) may influence attention capacity in adolescents. What is New? • Adolescents from the south of Europe had higher levels of attention capacity than their counterparts from the center, after accounting for socioeconomic factors, fitness, fatness and quality of diet. • These differences should be taken into account by educational institutions when promoting new approaches for putting into the practice student's capacities.