Health inequalities in urban adolescents: role of physical activity, diet, and genetics

Evaluation of physical fitness and health of young children aged between 3 and 6 based on cluster and factor analyses

BACKGROUND

As life improves and sedentary time increases, young children's physical fitness gradually declines.

METHODS

Multi-stage stratified whole cluster sampling was utilized to sample 5584 preschoolers. Young infants' morphology, function, and quality were revealed using cluster and factor analysis.

RESULTS

The cluster analysis separated 3-6-year-olds into two genders: 1,551 men in group A "high physical fitness" 1,499 men in group B "low physical fitness"; 1,213 women in group A and 1,321 women in group B. Young children's fitness was measured by standing long jump(1.00), weight(1.00), and height(1.00). A cluster analysis of 3-4-year-olds classified them into three groups: 272 "muscular strength," 75 "average physical fitness," and 250 "low agility." Young children's health depends on weight (1.00), height (0.57), and chest circumference (0.54). A cluster analysis of the 4-5-year-olds classified them into two groups: 1070 "balance" and 806 "muscular strength." Young children's health depends on weight (1.00), height (0.74), and chest circumference (0.71). A cluster analysis of the 5-6-year-olds divided them into three groups: 1762 "high physical fitness," 384 "obese," and 105 "low physical fitness." Young children's physical health depends on BMI (1.00), weight (1.00), and chest circumference (1.00). Factor analysis demonstrated that muscle strength, body shape, cardiovascular variables, and physical fitness composite components affected young children's health.

CONCLUSION

Women should focus on motor function and strength, while men on flexibility. Male group B "low physical fitness" should focus on strength, motor function, and balance, whereas male group A "high physical fitness" should focus on flexibility. Then, female group A "high physical fitness" should emphasize variety.2) For 3-4-year-olds, group A "muscular strength" should focus on flexibility, and group C "low agility" on motor function. 3) For 4-5-year-olds, group A "balanced" should focus on strength and motor function; 4) For 5-6-year-olds, group B "obese" should emphasize weight loss, and group C "low fitness" should emphasize strength, motor function, and flexibility; 5) Young children's physical fitness depends on muscle strength, body shape, cardiovascular factors, and physical fitness composite.

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.

Recreational Soccer Training Effects on Pediatric Populations Physical Fitness and Health: A Systematic Review

This systematic review analyzed the effects of recreational soccer programs on physical fitness and health-related outcomes in youth populations. Studies were sought in the following databases: (i) PubMed, (ii) Scopus, (iii) SPORTDiscus, and (iv) Web of Science. The eligibility criteria included (1) population: youth (<18 years old) populations with no restrictions on sex or health condition; (2) intervention: exposure to a recreational soccer training program of at least four weeks duration; (3) comparator: a passive or active control group not exposed to a recreational soccer training program; (4) outcomes: physical fitness (e.g., aerobic, strength, speed, and change-of-direction) or health-related measures (e.g., body composition, blood pressure, heart rate variability, and biomarkers); (5) study design: a randomized parallel group design. The search was conducted on 6 September 2022 with no restrictions as to date or language. The risk of bias was assessed using the PEDro scale for randomized controlled studies. From a pool of 37,235 potentially relevant articles, 17 were eligible for inclusion in this review. Most of the experimental studies revealed the beneficial effects of recreational soccer for improving aerobic fitness and its benefits in terms of blood pressure and heart-rate markers. However, body composition was not significantly improved by recreational soccer. The main results revealed that recreational soccer training programs that are implemented twice a week could improve the generality of physical fitness parameters and beneficially impact cardiovascular health and biomarkers. Thus, recreational soccer meets the conditions for being included in the physical education curriculum as a good strategy for the benefit of the general health of children and young people.

Implementation of a Physical Activity Program Protocol in Schoolchildren: Effects on the Endocrine Adipose Tissue and Cognitive Functions

Practicing exercise is one of the best strategies to promote well-being and quality of life, however physical activity in schoolchildren and adolescents is developed in an unpredictable, intermittent way and in short periods. There are relatively few intervention studies investigating the role of physical activity in schoolchildren endocrine function of adipose tissue and cognitive function. One hundred and three boys, divided into two groups: control (n = 51, did not perform additional physical activity) and exercise (n = 52, performed vigorous physical activity after the regular school classes). The exercise group, developed a 6 months physical activity protocol delivered by the physical education teacher during the second semester of the academic course (6 months). Body composition measurements, adherence to the Mediterranean diet, nutritional intake, hematological and biochemical parameters, endocrine function of the adipose tissue and biomarkers of brain molecular function were assessed at enrolment and after 6 months of intervention. No statistically significant differences between both groups were found for age, height and bone mass. Weight and BMI was lower in the exercise group compared to the control group, increasing lean mass and reducing fat mass. 58.68% of children in the exercise group showed high adherence to the Mediterranean Diet compared to 46.32% of the control group. The exercise group was more concerned about their diet consumed more fiber, vitamin B1, B2, B6, B12, D, Niacin, Folic acid, Fe, Zn, Se and Cu. Triglycerides levels and HDL-cholesterol were higher in the exercise group at the end of the study. Leptin, MCP-1, lipocalin-2, adipsin and PAI-1 levels were lower in the exercise group at the end of the exercise protocol. In contrast, adiponectin and osteocrin markedly increased in the exercise group. Moreover, marked increases were recorded in healthy brain state biomarkers (NGF, BDNF, and irisin) in the exercise group, which could have a positive impact on academic performance. Taken together, all the findings reported are consistent with many benefits of the exercise protocol on adipose tissue and brain molecular function, demonstrating the usefulness of early interventions based on physical activity in children to reduce risk factors related to sedentary lifestyle.

Cardiorespiratory Fitness in Youth: An Important Marker of Health: A Scientific Statement From the American Heart Association

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

Prevalence of severe/morbid obesity and other weight status and anthropometric reference standards in Spanish preschool children: The PREFIT project

BACKGROUND

Childhood obesity has become a major health problem in children under the age of 5 years. Providing reference standards would help paediatricians to detect and/or prevent health problems related to both low and high levels of body mass and to central adiposity later in life. Therefore, the aim of this study was to examine the prevalence of different weight status categories and to provide sex- and age-specific anthropometry reference standards for Spanish preschool children.

METHODS

A total of 3178 preschool children (4.59±0.87 years old) participated in this study. Prevalence of different degrees of obesity (mild, severe, and morbid) and other weight status categories were determined.

RESULTS

Reference standards were obtained. Prevalence of overweight and obese preschool children in the Spanish population ranged from 21.4 to 34.8%. Specifically, the obesity prevalence was 3.5, 1.2, and 1.3% of these subjects were categorized as mild, severe, and morbid obese. Sex- and age-specific reference standards for anthropometric parameters are provided for every 0.25 years (i.e. every trimester of life).

CONCLUSION

Our results show a high prevalence of overweight/obese preschoolers. The provided sex- and age-specific anthropometric reference standards could help paediatricians to track and monitor anthropometric changes at this early stage in order to prevent overweight/obesity.

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.

Association between 90o push-up and cardiorespiratory fitness: cross-sectional evidence of push-up as a tractable tool for physical fitness surveillance in youth

BACKGROUND

Despite being associated with health outcomes like abdominal adiposity, depression, anxiety, and cardiovascular disease risk among youth, largely, clinicians still do not adopt physical fitness testing. A clarion call for increased surveillance was previously issued, in order to address the US population-level lack of knowledge regarding pervasive inactivity among children. Because schools often do not send home annual physical fitness testing results, many lay parents are unaware of their child's physical fitness or the risk of associated adverse health outcomes. This study investigated associations between musculoskeletal fitness measures (including 90^o push-up), cardiorespiratory fitness, and weight status.

METHODS

Two hundred and ten students (9.7 ± 1.08 years, 138.6 ± 9.4 cm; 42.3 ± 14.4 kg) across third through fifth grades were tested for cardiorespiratory (i.e., Progressive Aerobic Cardiovascular Endurance Run (PACER)) and musculoskeletal (90^o push-up, trunk lift, sit-and-reach and curl-up) fitness. The relationships between measures of musculoskeletal and cardiorespiratory fitness were modeled using a series of linear regression analyses. Models were adjusted for age, sex, and weight status. Significant two-tailed tests were set at p < .05.

RESULTS

Of the four musculoskeletal fitness measures, only 90^o push-up was significantly associated (β = .353; p < .001) with PACER test scores (i.e., cardiorespiratory fitness). The related model (R² = .324; F (4,205) = 26.061; p < .001) accounted for 32% of the variance in cardiorespiratory fitness. 90^o push-up was associated with sit-and reach (β = .298; p < .001) and curl up (β = .413; p < = .001) test scores. When individually modeled, 90^o push-up (β = -.461; p < .001) and PACER (β = -.436; p < .001) were inversely associated with weight status.

CONCLUSIONS

The 90^o push-up test (a measure of upper body muscle strength and endurance) was associated with cardiorespiratory fitness, anterior trunk muscle strength and endurance, and lower back and posterior thigh muscle flexibility in youth aged 8-12 years old. Although the current findings do not establish a causal relationship, it is concluded that the 90^o push-up test is a tractable tool for physical fitness surveillance by clinicians, parents, and possibly youth themselves.

Differences in Cardiorespiratory Fitness between Chinese and Japanese Children and Adolescents

Background: This study aimed to compare the difference in cardiorespiratory fitness between Chinese and Japanese children and adolescents. Methods: Participants comprised 9025 children and adolescents aged 7–18 years from China and Japan. Cardiorespiratory fitness (CRF) was measured by performance in the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO_2max). Differences in CRF between countries were evaluated by t-tests. Centile curves for the 20mSRT and VO_2max values were constructed for Chinese and Japanese children and adolescents, respectively, using the Lambda Mu and Sigma (LMS) method. Results: (1) For most of the age groups, the 20mSRT and VO_2max performances among Chinese participants were lower than among Japanese participants. (2) Japanese children had the most apparent gains in P₁₀, P₅₀, and P₉₀ VO_2max values in primary school; however, they gradually decreased in middle school. For Chinese girls, the P₁₀, P₅₀, and P₉₀ VO_2max values decreased gradually with age. (3) The VO_2max value among Japanese children increased; however, it decreased or remained flat among Chinese children in primary school. Conclusions: CRF among Chinese participants was lower than among Japanese participants while the VO_2max value showed different trends in primary school. Effective measures should be taken to improve CRF among children and adolescents.

The cross-sectional relationships between consumption of takeaway food, eating meals outside the home and diet quality in British adolescents

OBJECTIVE

The present study aimed to evaluate the association of frequency of consuming takeaway meals and meals out with diet quality of UK adolescents.

DESIGN

The Diet Quality Index for Adolescents (DQI-A) tool was used to assess diet quality, where adolescents' food intake was based on 4d diary records obtained from the UK cross-sectional National Diet and Nutrition Survey (NDNS) rolling programme Years 1-6. Models included confounders.

SETTING

The DQI-A relies on three components, specifically diet quality, diversity and equilibrium, which reflect the degree of adherence of an adolescent's diet with food-based dietary guidelines.ParticipantsBritish (n 2045) adolescents aged 11-18 years.

RESULTS

Mean diet quality score for all adolescents was 20·4 % (overall DQI-A score range: -33 to 100 %). After adjusting for age, gender and equivalised household income, DQI-A% score was higher for low and moderate takeaway consumers by 7·4 % (95 % CI 5·5, 9·2; P&lt;0·01) and 3·5 % (95 % CI 1·9, 5·1; P&lt;0·01), respectively, v. frequent consumers. Significant differences were also observed between low, moderate and frequent takeaway consumers among all DQI-A components and sub-components (P&lt;0·05), except for the diet adequacy sub-component (DAx). Results for frequent consumption of meals out were similar but attenuated and not statistically significant for individual components before or after adjusting for confounders.

CONCLUSIONS

Frequent consumption of takeaway meals may have a negative impact on adolescents' diet quality and therefore policies to reduce the intake of takeaways should be considered in this age group.

Making a Case for Cardiorespiratory Fitness Surveillance Among Children and Youth

We review the evidence that supports cardiorespiratory fitness (CRF) as an important indicator of current and future health among school-aged children and youth, independent of physical activity levels. We discuss the merit of CRF measurement for population health surveillance and propose the development of CRF guidelines to help support regional, national, and international surveillance efforts.

Physical fitness reference standards for preschool children: The PREFIT project

OBJECTIVES

Reference values are necessary for classifying children, for health screening, and for early prevention as many non-communicable diseases aggravate during growth and development. While physical fitness reference standards are available in children aged 6 and older, such information is lacking in preschool children. Therefore, the purposes of this study were (1) to provide sex-and age-specific physical fitness reference standards for Spanish preschool children; and (2) to study sex differences across this age period and to characterise fitness performance throughout the preschool period.

DESIGN

Cross-sectional.

METHODS

A total of 3179 preschool children (1678 boys) aged 2.8-6.4 years old from Spain were included in the present study. Physical fitness was measured using the PREFIT battery.

RESULTS

Age- and sex-specific percentiles for the physical fitness components are provided. Boys performed better than girls in the cardiorespiratory fitness, muscular strength, and speed-agility tests over the whole preschool period studied and for the different percentiles. In contrast, girls performed slightly better than boys in the balance test. Older children had better performance in all fitness tests than their younger counterparts.

CONCLUSIONS

Our study provides age- and sex-specific physical fitness reference standards in preschool children allowing interpretation of fitness assessment. Sexual dimorphism in fitness tests exists already at preschool age, and these differences become larger with age. These findings will help health, sport, and school professionals to identify preschool children with a high/very low fitness level, to examine changes in fitness over time, and to analyse those changes obtained due to intervention effects.

Relationship between Body Mass Index, Cardiorespiratory and Musculoskeletal Fitness among South African Adolescent Girls

Background: Cardiorespiratory and musculoskeletal fitness are important health indicators that support optimal physical functioning. Understanding the relationship between body mass index and these health markers may contribute to the development of evidence-based interventions to address obesity-related complications. The relationship between body mass index, cardiorespiratory and musculoskeletal fitness has not been well explored, particularly in female adolescents. The aim of this study was to investigate the association between body mass index, cardiorespiratory and musculoskeletal fitness among South African adolescent girls in low-income communities. Methods: This cross-sectional study included 151 adolescent girls, aged 13⁻16 years. Cardiorespiratory fitness was measured using the 20 m shuttle run test and musculoskeletal fitness was assessed using a variety of field-based tests. Height and weight were measured with standardised procedures and body mass index (BMI) was derived by the formula [BMI = weight (kg)/height (m)²]. Participants were categorised into three BMI groups using the International Obesity Task Force age- and gender-specific cut-off points. Pearson correlations were used to determine the association between body mass index, cardiorespiratory fitness and measures of musculoskeletal fitness at p ≤ 0.05. Results: Overweight and obese girls were found to have lower cardiorespiratory fitness, decreased lower extremity muscular strength, greater grip strength, and more hypermobile joints compared to normal-weight peers. BMI was negatively associated with cardiorespiratory fitness and lower extremity muscular strength. Conclusions: The findings indicate that increased body mass correlates with decreased cardiorespiratory and musculoskeletal fitness. Interventions should be developed to target these important components of physical fitness in this demographic group.

Correlates of ideal cardiovascular health in European adolescents: The HELENA study

BACKGROUND AND AIMS

The ideal cardiovascular health (iCVH) construct consists of 4 health behaviors (smoking status, body mass index, physical activity and diet) and 3 health factors (total cholesterol, blood pressure and fasting glucose). A greater number of iCVH components in adolescence are related to better cardiovascular health, but little is known about the correlates of iCVH in adolescents. Thus, the aim of the study was to examine correlates of iCVH in European adolescents.

METHODS AND RESULTS

The study comprised 637 European adolescents with complete iCVH data. Participants were part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional, multicenter study conducted in 9 different European countries. Correlates investigated were sex and age, family affluence scale, maternal education, geographic location, sleep time, television viewing, duration of pregnancy, birth weight and breastfeeding. Younger adolescents, those whose mothers had medium/high education or those who watched television less than 2 h per day had a greater number of iCVH components compared to those who were older, had a mother with low education or watched television 2 h or more daily (P ≤ 0.01).

CONCLUSION

Since in our study older adolescents had worse iCVH than younger adolescents, early promotion of cardiovascular health may be important. Future studies may also investigate the usefulness of limiting television viewing to promote iCVH. Finally, since adolescents of mothers with low education had poorer iCVH, it may be of special interest to tailor public health promotion to adolescents from families with low socioeconomic status.

Dietary Patterns in European and Brazilian Adolescents: Comparisons and Associations with Socioeconomic Factors

Associations between dietary patterns (DP) and socioeconomic factors have been little explored in adolescents. The aim of this study was to identify DP in European and Brazilian adolescents and to investigate their associations with a range of socioeconomic indicators. Adolescents from the HELENA-study and the Household Budget Survey were analyzed. Factor analysis was used to obtain DP. Linear regression was used to examine the association between DP and SES. In Europeans, the Western DP was associated with low education of the mother, high socioeconomic status (boys), older age (boys), and living in cities of the Northern Europe; in Brazilians, the Western DP was associated with high secondary education of the mother, high socioeconomic status and living in Southern areas of the country. The Traditional European DP, in both genders, was associated with high secondary education of the mother and inversely associated with a high socioeconomic status; the Traditional Brazilian DP, was associated with university level education of the mother and older age (boys). The association between DP and socioeconomic factors is relevant for the understanding of food-related practices and highlight the importance of performing a complete assessment of the socioeconomic influence in adolescent's DP from developed and developing countries.

FTO POLYMORPHISM AND PHYSICAL FITNESS IN OBESE SCHOOLCHILDREN AFTER AN INTERVENTION PROGRAM

ABSTRACT Introduction: Recent studies have shown that the association of FTO rs9939609 gene polymorphism with obesity depends on the level of the individual’s physical activity. However, there are some studies that evaluated physical fitness, health, and motor performance in relation to the rs9939609 FTO gene polymorphism. Objective: To evaluate how the rs9939609 FTO gene polymorphism affects the results of physical fitness tests related to health and athletic performance in schoolchildren after 4 months of intervention of physical exercise. Method: The rs9939609 FTO gene polymorphism was genotyped in a total of 36 schoolchildren from southern Brazil, aged 8 to 16 years. Body mass index (BMI), health-related physical fitness (cardiorespiratory fitness, abdominal strength/endurance, and flexibility) and motor performance (upper and lower limb strength, agility, and speed) were evaluated. The intervention included exercise strategies based on Physical Education, healthy eating, and oral and postural care. Results: In the experimental group, after the intervention, significant differences were noted in individuals with the TT genotype. These individuals showed improvements in abdominal strength (p=0.025), lower limb strength (p=0.037) and agility (p=0.021). For individuals with the AA/AT genotype, improvements in flexibility (p=0.026), abdominal strength (p=0.002), upper limb strength (p=0.008) and lower limb strength (p=0.001) were observed. However, these differences were not statistically significant when comparing the TT and AT/AA genotypes. Conclusions: The experimental group showed improvements in abdominal strength, lower limb strength, and speed. Yet, individuals with different genotypes (AA/AT and TT) for polymorphism rs9939609 exhibited similar values for indicators of physical fitness, health, and motor performance. Level of Evidence II; Lesser quality RCT.

European normative values for physical fitness in children and adolescents aged 9-17 years: results from 2 779 165 Eurofit performances representing 30 countries

OBJECTIVE

To develop sex-specific and age-specific normative values for the nine Eurofit tests in European children and adolescents aged 9-17 years.

METHODS

A systematic review was undertaken to identify papers that explicitly reported descriptive results for at least one of nine Eurofit tests (measuring balance, muscular strength, muscular endurance, muscular power, flexibility, speed, speed-agility and cardiorespiratory fitness (CRF)) on children and adolescents. Data were included on apparently healthy (free from known disease/injury) children and adolescents aged 9-17 years. Following harmonisation for methodological variation where appropriate, pseudodata were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu Sigma (LMS) method. Sex-specific and age-specific differences were expressed as standardised differences in means, with the percentage of children and adolescents with healthy CRF estimated at the sex-age level.

RESULTS

Norms were displayed as tabulated centiles and as smoothed centile curves for the nine Eurofit tests. The final dataset included 2 779 165 results on children and adolescents from 30 European countries, extracted from 98 studies. On average, 78% of boys (95% CI 72% to 85%) and 83% of girls (95% CI 71% to 96%) met the standards for healthy CRF, with the percentage meeting the standards decreasing with age. Boys performed substantially (standardised differences >0.2) better than girls on muscular strength, muscular power, muscular endurance, speed-agility and CRF tests, but worse on the flexibility test. Physical fitness generally improved at a faster rate in boys than in girls, especially during the teenage years.

CONCLUSION

This study provides the largest and most geographically representative sex-specific and age-specific European normative values for children and adolescents, which have utility for health and fitness screening, profiling, monitoring and surveillance.

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.

Prevalence of Metabolically Healthy but Overweight/Obese Phenotype and Its Association With Sedentary Time, Physical Activity, and Fitness

PURPOSE

Childhood obesity is one of the major concerns in the last years due to the association with future health problems and all-cause mortality. However, there is a subset of adolescents with overweight/obesity who present a metabolic healthy profile. Therefore, the aim of this study was to examine the prevalence of metabolically healthy but overweight/obese adolescents and whether sedentary time, physical activity, and fitness differ between metabolically healthy and nonmetabolically healthy phenotypes.

METHODS

A subsample of 237 European adolescents from the HEalthy Lifestyle in Europe by Nutrition in Adolescence study (n = 3,528, participation rate: 61.3%) with overweight/obesity were included. The study sample was not fully representative for the European adolescent population. Based on sex- and age-specific metabolic syndrome cutoff points for triglycerides, glucose, blood pressure, and high-density cholesterol participants were classified as metabolically healthy or nonmetabolically healthy. Sedentary time, physical activity, and fitness were assessed by accelerometry and the Alpha battery, respectively.

RESULTS

The prevalence of metabolically healthy status in adolescents with overweight and obesity was higher in girls (87%) than in boys (74%, p = .019), being similar when only obesity was considered. Sedentary time was lower in metabolically healthy overweight/obese than in nonmetabolically healthy participants (mean difference = 48.0 minutes, p = .012). Moderate and moderate-to-vigorous physical activity were higher (p's < .05) in metabolically healthy than in nonmetabolically healthy adolescents with overweight/obesity (mean difference = 7.9 min/day and 10.9 min/day, respectively). No significant differences were found in fitness. Overall, these results persisted when only adolescents with obesity were included in the analyses.

CONCLUSIONS

Metabolically healthy adolescents with overweight/obesity are less sedentary and more active than their nonmetabolically healthy peers with overweight/obesity, yet consistent differences in fitness were not observed.

Factors Associated with Dental Pain in Mexican Schoolchildren Aged 6 to 12 Years

OBJECTIVE

To identify dental pain prevalence and associated factors in Mexican schoolchildren.

METHODS

This cross-sectional study included 1,404 schoolchildren aged 6 to 12 years from public schools in the city of Pachuca de Soto, Hidalgo, Mexico. Data were collected through a questionnaire that addressed sociodemographic and socioeconomic factors, eating and dental hygiene habits, and behavior variables. The dependent variable was self-reported dental pain in the 12 months prior to the survey. Data were analyzed using nonparametric statistics and a binary logistical regression model.

RESULTS

Dental pain prevalence among the studied children was 49.9%. The variables associated in the final model (p < 0.05) were younger mother's age, higher socioeconomic level, absence of an automobile in the home, fried food, fruit intake, lower tooth brushing frequency, never having used mouthwash or not knowing about it, and parents/guardians with regular to high levels of knowledge about oral health and a regular or good/very good perception of their child's oral health.

CONCLUSIONS

One in two children in the study had experienced dental pain in the twelve months prior to the survey. The association of socioeconomic variables with dental pain suggested inequalities among the children in terms of oral health.

Fragmentation of daily rhythms associates with obesity and cardiorespiratory fitness in adolescents: The HELENA study

BACKGROUND & AIMS

Chronobiology studies periodic changes in living organisms and it has been proposed as a promising approach to investigate obesity. We analyze the association of the characteristics of the rest-activity rhythms with obesity, cardiorespiratory fitness and metabolic risk in adolescents from nine European countries.

METHODS

1044 adolescents (12.5-17.5 y) were studied. Circadian health was evaluated by actigraphy with accelerometers (Actigraph GT1M). Characteristics of the daytime activity such as fragmentation (intradaily variability), estimated acrophase, and 10 h mean daytime activity index were obtained. Body composition was assessed using Bioelectrical-Impedance-Analysis, skinfold thickness, air-displacement-plethysmography and Dual-energy-X-ray-Absorptiometry. Cardiorespiratory fitness (VO_2max) and metabolic risk were studied.

RESULTS

Highly fragmented activity rhythms were associated with obesity and central adiposity (P < 0.05). Obese adolescents had ∼3 times higher odds of having a high fragmentation of daytime activity compared to normal weight adolescents OR (95% CI) = 2.8 (1.170, 6.443). A highly fragmented rhythm was also related to lower cardiorespiratory fitness and higher metabolic risk (P < 0.05) so those adolescents classified as low fitness showed a significantly higher fragmentation of daytime activity than those included in the high fitness group (P < 0.0001). Other characteristics of the rhythms such as smaller 10 h daytime mean activity index and delayed estimated acrophase were also related to obesity and metabolic risk (P < 0.05).

CONCLUSIONS

Our results indicate that the daily organization of the rest-activity cycle is more fragmented in obese and less fit adolescents and correlates with higher metabolic risk. This fact reinforces our hypothesis that disturbances in daily rhythms can be considered as sensitive markers of poorer adolescent's health.

Prevalence of overweight/obesity and fitness level in preschool children from the north compared with the south of Europe: an exploration with two countries

BACKGROUND

North-south differences in the prevalence of obesity and fitness levels have been found in European adolescents, yet it is unknown if such differences already exist in very young children.

OBJECTIVES

This study aims to compare the prevalence of overweight/obesity and fitness levels in preschool children aged 4 years from Sweden (north of Europe) and Spain (south of Europe).

METHODS

The sample consisted of 315 Swedish and 128 Spanish preschoolers. Anthropometry (weight, height, waist circumference) and fitness (strength, speed-agility, balance and cardiorespiratory fitness) were assessed. Analysis of covariance adjusted for age, sex and height/body mass index (BMI) was used.

RESULTS

Preschool children from Sweden had lower prevalence of overweight/obesity than their peers from Spain (World Obesity Federation, mean difference, MD = -9%, P = 0.010; World Health Organization, MD = -11%, P = 0.011). Concerning fitness, preschoolers from Spain were more fit in terms of upper-muscular strength (MD = +0.4 kg, P = 0.010), speed-agility (MD = -1.9 s, P = 0.001), balance (MD = +4.0 s, P = 0.001) and cardiorespiratory fitness (MD = boys = +6.6 laps, girls = +2.3 laps; P < 0.001 for all), yet they had worse lower-muscular strength (MD = -7.1, P ≤ 0.001) than those from Sweden. Differences in upper-muscular strength were largely explained by differences in BMI, and differences in cardiorespiratory fitness should be interpreted cautiously due to some methodological deviations.

CONCLUSIONS

These findings suggest that a higher prevalence of overweight/obesity in Spain compared with Sweden is present already at early childhood, while differences in physical fitness components showed mixed findings.

International variability in 20 m shuttle run performance in children and youth: who are the fittest from a 50-country comparison? A systematic literature review with pooling of aggregate results

OBJECTIVES

To describe and compare 20 m shuttle run test (20mSRT) performance among children and youth across 50 countries; to explore broad socioeconomic indicators that correlate with 20mSRT performance in children and youth across countries and to evaluate the utility of the 20mSRT as an international population health indicator for children and youth.

METHODS

A systematic review was undertaken to identify papers that explicitly reported descriptive 20mSRT (with 1-min stages) data on apparently healthy 9-17 year-olds. Descriptive data were standardised to running speed (km/h) at the last completed stage. Country-specific 20mSRT performance indices were calculated as population-weighted mean z-scores relative to all children of the same age and sex from all countries. Countries were categorised into developed and developing groups based on the Human Development Index, and a correlational analysis was performed to describe the association between country-specific performance indices and broad socioeconomic indicators using Spearman's rank correlation coefficient.

RESULTS

Performance indices were calculated for 50 countries using collated data on 1 142 026 children and youth aged 9-17 years. The best performing countries were from Africa and Central-Northern Europe. Countries from South America were consistently among the worst performing countries. Country-specific income inequality (Gini index) was a strong negative correlate of the performance index across all 50 countries.

CONCLUSIONS

The pattern of variability in the performance index broadly supports the theory of a physical activity transition and income inequality as the strongest structural determinant of health in children and youth. This simple and cost-effective assessment would be a powerful tool for international population health surveillance.

The effect of snacking and eating frequency on dietary quality in British adolescents

PURPOSE

To describe the effects of number of eating occasions and snacks on dietary quality (DQ), defined as adherence to dietary recommendations.

METHODS

A sample of 884 adolescents (11-18 years) in the UK National Diet and Nutrition Survey (NDNS) were included. The Diet Quality Index for Adolescents (DQI-A) was implemented. The total number of eating occasions and snacks was frequency of food or beverages consumed over 24 h and frequency of foods or beverages consumed outside of the three mealtimes, respectively. Results were generated with and without low-energy food under 210 kJ (50 kcal). Regression models were generated with DQ score as the outcome variable and number of eating occasions and snacks as predictors.

RESULTS

The mean (95 % CI) DQ score was 31.1 % (30.2, 32.0). The mean number of eating occasions and snacks was 7.5 (7.3, 7.7) and 2.6 (2.6, 2.7) times/day, respectively. When low-energy events were excluded, the mean number of eating occasions and snacks reduced to 6.2 (6.1, 6.4) and 2.0 (2.0, 2.1) times/day, respectively. DQ score increased by 0.74 points (0.42, 1.05; p < 0.01) and 0.55 points (-0.08, 0.69; p = 0.17) for total eating occasions and snacks, respectively. When low-energy events were excluded, DQ score increased by 0.30 points (-0.84, 0.69; p = 0.13) for each eating occasion and decreased by 1.20 points (-2.1, -0.3; p < 0.01) for each snack.

CONCLUSION

Eating more frequently improves dietary quality especially if some eating occasions are low in energy. A focus on replacing high-energy snacks with low-energy alternatives rather than reducing the number of eating occasions may result in improved dietary quality in adolescents.