The associations between meeting 24-hour movement guidelines and adiposity in Asian Adolescents: The Asia-Fit Study

Less is known about how compliance with 24-hour movement guidelines for physical activity (PA), sedentary behavior, and sleep affects adiposity in young people. The purposes of this study were to compare compliance with 24-hour movement guidelines in Asian adolescents and to examine the associations between compliance with 24-hour movement guidelines and body fat percentage. A sample of 12 590 adolescents aged 13.63 (± 1.01) years from eight Asian metropolitan cities including Bangkok (Thailand), Hong Kong SAR, Kuala Lumpur (Malaysia), Seoul (South Korea), Shanghai (China), Singapore, Taipei (Taiwan), and Tokyo (Japan) completed interviewer-administered questionnaires to assess moderate-to-vigorous PA, recreational screen time, sleep duration, and covariates. Body fat percentage was measured using bioelectrical impedance analysis. We found that compliance with 24-hour movement guidelines differed in Asian adolescents across the eight cities. Adjusting for covariates, there was a negative association between number of the guidelines being met and body fat percentage in Asian adolescents. In addition, meeting only the sleep guideline and both the PA and sleep guidelines had negative associations with body fat percentage compared with no guidelines being met. Our findings improve the understanding about how compliance with 24-hour movement guidelines benefit a healthy body weight in adolescents, as well as contribute to development of evidence-based 24-hour movement guidelines for Asian young people. Future research is needed to gain better insights into the directionality of the associations between compliance with 24-hour movement guidelines and adiposity, as well as the mechanisms underlying the associations in Asian adolescents.

Moderate-to-vigorous physical activity attenuates the detrimental effects of television viewing on the cardiorespiratory fitness in Asian adolescents: the Asia-fit study

BACKGROUND

Moderate-to-vigorous physical activity (MVPA) and television viewing are independently associated with cardiorespiratory fitness. However, limited evidence is available on their combined effects, specifically of MVPA and watching television, on cardiorespiratory fitness in the young Asian population. Therefore, the present study examined whether MVPA can attenuate the detrimental effects of prolonged television viewing on the cardiorespiratory fitness of Asian adolescents.

METHODS

This is a cross-sectional study on 9553 adolescents (aged 12-15 years) from 8 Asian metropolitan cities (Tokyo, Hong Kong, Shanghai, Taipei, Bangkok, Kuala Lumpur, Seoul, and Singapore). Cardiorespiratory fitness was assessed by using a 15-m progressive aerobic capacity endurance run (PACER) test. The time spent on MVPA and watching television was assessed using the International Physical Activity Questionnaire-Short Form.

RESULTS

MVPA was more closely associated with the PACER score than the duration of watching television. Compared with the reference group (i.e. those with the lowest levels of MVPA [< 30 min/day] and the most sedentary [≥3 h/day of television time]), PACER scores were significantly higher for those who met the physical activity recommendation (≥60 min/day in MVPA), regardless of the duration of television viewing. Conversely, girls in the least active group (< 30 min/day of MVPA) who watched television < 1 h/day demonstrated better PACER scores than the reference group.

CONCLUSIONS

Sufficient MVPA (≥60 min/day) can attenuate the detrimental effects of excessive television viewing with cardiorespiratory fitness in Asian adolescents. In addition, the duration of television viewing had significant but weaker associations with cardiorespiratory fitness compared to MVPA.

Physical activity and health-related fitness in Asian adolescents: The Asia-fit study

Purpose: The present study aimed to investigate and compare physical activity (PA) and health-related fitness in Asian adolescents, and to examine the associations between meeting PA guidelines and attaining fitness standards. Methods: A sample of 12,590 adolescents (M_age = 13.63 years, SD = 1.01) from eight Asian metropolitan cities completed measurements of PA, five field-based fitness tests, and covariates. The fitness test scores were further classified into Healthy Fitness Zone (HFZ) or Needs Improvement Zone (NIZ). Results: Findings showed that adolescents' levels of PA and fitness components differed by cities. City differences were also found in proportions of meeting PA guidelines and achieving the HFZs of aerobic capacity, muscular fitness, and body composition. After controlling covariates, meeting PA guidelines positively associated with being in the HFZs of aerobic and muscular fitness, but the association was not significant with being in the body composition HFZ. Conclusion: There was a large variation in PA and health-related fitness in adolescents across the eight Asian cities. Asian adolescents achieving PA guidelines were more likely to be in the HFZ of aerobic and muscular fitness. Prospective follow-up studies are warranted to gain better insights into the relationships between objectively-measured PA and fitness.

Nutrifit Programme to Improve Health-Related Fitness among Young Thai Schoolchildren

A Nutrifit programme, consisting of a nutrition education and physical training model, was developed by modifying an established Fitnessgram as a tool. the programme was tested among 514 schoolchildren aged eight to nine years who were enrolled in two provincial government schools (A and B) and two private schools (C and D) in the Bangkok Metropolitan Area. Health-related fitness tests using the Fitnessgram were administered in all four schools, followed by the Nutrifit programme intervention in schools B and D. the intervention included 10 nutrition and physical training education sessions during the regular physical education classes. During the seven-month programme period, though the nutritional status of children did not show a significant change, improvement in health-related fitness tests was noted in both non-intervened and intervened schools. It is recommended that the Nutrifit programme be incorporated into the school curriculum as a measure of nutrition and fitness aimed at health promotion and disease prevention.

Low Sleeping Time, High TV Viewing Time, and Physical Inactivity in School Are Risk Factors for Obesity in Pre-Adolescent Thai Children

OBJECTIVE

Explore the association between physically active behavior and obesity in 7- to 12-years-old Thai children.

MATERIAL AND METHOD

As part of SEANUTS Thailand, information on anthropometry, physical activity, and sociodemographic variables were collected in 7- to 12-years-old urban and rural Thai children. Multi-stage sampling technique was used and 1,345 children (32% urban, and 50.3% boys) participated in the study. Anthropometric measurements included weight, height, and BMI-for-age Z-scores (BAZ) using World Health Organization Growth Reference. Obesity was defined as BAZ > 2SD. Physical activity was assessed using a validated physical activity questionnaire (PAQ). The PAQ provided an activity score, activity time in school, sleeping hours, and TV watching time as categorical variable, low, moderate, and high. Chi-square by likelihood ratio test and logistic regression were used to compare obese and non-obese groups.

RESULTS

The overall prevalence of overweight and obesity was 10.2 and 10.8% respectively, whereas 8.2% was classified as thin. Maternal education and religion did not differ between obese and non-obese children. However, obese children's family income was higher. After controlling for family income, maternal education, and religion, obese children were significantly less active during break times in school, slept less, and watched more TV than non-obese. However, there was no difference in the activity score of obese and non-obese children.

CONCLUSION

The study showed that physical activity during break time in school, sleep duration, and hours of TV viewing were associated with obesity in pre-adolescent Thai children. It is important to note that activity score was not associated with obesity. One of the most important benefits to be physically active in childhood is the potential to maintain this behavior into adulthood. Therefore, programs that encourage healthy behaviors and address these modifiable risk factors should be incorporated in the school curriculum.

Bone status measured by quantitative ultrasound: a comparison with DXA in Thai children

BACKGROUND/OBJECTIVES

Quantitative ultrasound (QUS) is used to measure bone quality and is known to be safe, radiation free and relatively inexpensive compared with dual-energy X-ray absorptiometry (DXA) that is considered the gold standard for bone status assessments. However, there is no consensus regarding the validity of QUS for measuring bone status. The aim of this study was to compare QUS and DXA in assessing bone status in Thai children.

SUBJECTS/METHODS

A total of 181 Thai children (90 boys and 91 girls) aged 6 to 12 years were recruited. Bone status was measured by two different techniques in terms of the speed of sound (SOS) using QUS and bone mineral density (BMD) using DXA. Calcium intake was assessed by 24 h diet recall. Pearson's correlation, κ-statistic and Bland and Altman analysis were used to assess the agreement between the methods.

RESULTS

There was no correlation between the two different techniques. Mean difference (s.d.) of the Z-scores of BMD and SOS was -0.61 (1.27) that was different from zero (P<0.05). Tertiles of Z-scores of BMD and QUS showed low agreement (κ 0.022, P=0.677) and the limits of agreement in Bland and Altman statistics were wide.

CONCLUSIONS

Although QUS is easy and convenient to use, the SOS measurements at the radius seem not appropriate for assessing bone quality status.

Lactose-free milk prolonged endurance capacity in lactose intolerant Asian males

Background

Several studies on Caucasian volunteers have proven that milk is an effective recovery drink for athletes. Such benefit, however, cannot be directly applied to the lactose-intolerant Asian population. This study investigated the effects of ingesting water (WT), sports drink (SPD) and lactose-free milk (LFM) on cycling capacity.

Methods

Ten healthy young men completed 3 randomized experimental trials. Each trial consisted of an intermittent glycogen depleting session, a 2 h recovery period during which they ingested the test drink, followed by cycling at 70% of their maximum oxygen consumption (VO₂max) to volitional exhaustion. Each trial was separated by at least one week.

Results

There were no complaints or symptoms of lactose intolerance during any of the trials. The cycling periods were different (p < 0.05) amongst the 3 trials, namely, lactose-free milk (LFM; 69.6 ± 14.0 min), sports drink (SPD; 52.1 ± 11.6 min), and water (WT; 36.0 ± 11.1 min), respectively. The VO₂ and VCO₂ of LFM (30 ± 4 and 29 ± 4 ml/kg/min) were lower (p < 0.05) than that of SPD (34 ± 4 and 34 ± 4 ml/kg/min) and WT (35 ± 4 and 33 ± 5 ml/kg/min). There were no differences (p = 0.45) in VO₂ and VCO₂ between SPD and WT. Mean rating of perceived exertion was lowest in LFM (14 ± 5; p < 0.05), while no difference was found between the other two trials (SPD: 16 ± 4 and WT: 16 ± 4; p = 0.18).

Conclusion

Lactose-free milk is likely to be an effective recovery drink for enhancing subsequent cycling capacity in lactose intolerant Asian males.

Multicompartment model comparison of body fat assessment in Thai adolescents

OBJECTIVE

To examine the limits of agreement of percent body fat (%BF) assessed by different compartment models (2C and 3C compared to 4C).

MATERIAL AND METHOD

Fifty-one healthy Thai adolescents (25 males and 26 females) aged 16 to 19 years volunteered in the present study. Underwater weighing (UWW) and dual energy X-ray absorptiometry (DEXA) were used for measurement of %BF for 2C and 3C models. UWW was also used for body density, DEXA for bone mineral content and protein content, and deuterium oxide dilution method for total body water (TBW), used in Lohman's equation for 4C model.

RESULTS

Body density total body water; bone mineral density, and fat free mass were significantly higher in males than in females, whereas females had significantly higher fat than males (p < 0.001). Compared to %BF4C, %BF(UWW) did not show significant deviations from the line of identity in males and females (R2 = 0.85 and 0.75 respectively), whereas %BF(DEXA) showed significant deviations from the line of identity in females (R2 = 0.59), but not in males (R2 = 0.60). Bland & Altman analysis demonstrated that UWW and DEXA tended to underestimate %BF in leaner adolescents and overestimate %BF in fatter adolescents.

CONCLUSION

Percent body fat using underwater weighing (2C model) may be used interchangeable with the 4C model in both genders. However; DEXA (3C model) can only be used in males and not in females, which require further research. A regression equation to relate 2C and 3C models to 4C was developed to enable a better estimation of percent body fat in Thai adolescents.

Ethnic differences in body fat distribution among Asian pre-pubertal children: a cross-sectional multicenter study

Background

Ethnic differences in body fat distribution contribute to ethnic differences in cardiovascular morbidities and diabetes. However few data are available on differences in fat distribution in Asian children from various backgrounds. Therefore, the current study aimed to explore ethnic differences in body fat distribution among Asian children from four countries.

Methods

A total of 758 children aged 8-10 y from China, Lebanon, Malaysia and Thailand were recruited using a non-random purposive sampling approach to enrol children encompassing a wide BMI range. Height, weight, waist circumference (WC), fat mass (FM, derived from total body water [TBW] estimation using the deuterium dilution technique) and skinfold thickness (SFT) at biceps, triceps, subscapular, supraspinale and medial calf were collected.

Results

After controlling for height and weight, Chinese and Thai children had a significantly higher WC than their Lebanese and Malay counterparts. Chinese and Thais tended to have higher trunk fat deposits than Lebanese and Malays reflected in trunk SFT, trunk/upper extremity ratio or supraspinale/upper extremity ratio after adjustment for age and total body fat. The subscapular/supraspinale skinfold ratio was lower in Chinese and Thais compared with Lebanese and Malays after correcting for trunk SFT.

Conclusions

Asian pre-pubertal children from different origins vary in body fat distribution. These results indicate the importance of population-specific WC cut-off points or other fat distribution indices to identify the population at risk of obesity-related health problems.

Study on different sites of waist circumference and its relationship to weight-for-height index in Thai adolescents

OBJECTIVE

To compare waist circumference (WC) measured at different sites of trunk region and to determine predictive WC values that were corresponding to weight-for-height index in Thai adolescents.

MATERIAL AND METHOD

The authors conducted the cross-sectional study in 509 adolescents, aged 10-18 years old WC was measured at four different sites of trunk region, WC1; at midway between the lowest rib and the iliac crest, WC2; at the narrowest waist, WC3; at immediately above the iliac crest and WC4; at the umbilicus level. Receiver operating characteristic analysis was also performed to determine WC cutoffs to maximize the sensitivity and specificity.

RESULTS

WC measured at all four sites provided small different powerful value in prediction of trunk fat and total body fat (TBF) in adolescents and that WC4 provided slightly better predictive value than other WC. In boys, WC provided better prediction of trunk fat than the prediction of TBF, whereas in girls, the prediction of trunk fat and TBF from WC were of similar magnitude. By receiver operating characteristic analysis, WC risk threshold for predicting the overweight adolescents using Thai weight-for-height Z score > or = 1.5 SD as reference was 73.5 cm for boys (sensitivity 96.8%, specificity 85.7%) and 72.3 cm for girls (sensitivity 96.1%, sensitivity 80.5%). WC threshold was increased to 75.8 cm. (sensitivity 96.3.%, specificity 86.4%) for boys and 74.6 cm for girls (sensitivity 95.1%, specificity 85.7%) in order to detect the obese children.

CONCLUSION

Waist circumference has been proposed as the simple tool for screening the overweight adolescents and when measured at the umbilicus level, it is considered the feasible site for self-evaluation. Further study is needed to investigate the relationship between the increased WC and metabolic risk factors for obesity in adolescents.