Body Mass Index standards based on agreement with health-related body fat

The effects of capsaicin intake on weight loss among overweight and obese subjects: a systematic review and meta-analysis of randomised controlled trials

Animal studies have shown that capsaicin plays a positive role in weight management. However, the results in human research are controversial. Therefore, the present systematic review and meta-analysis aimed to evaluate the effect of capsaicin on weight loss in adults. We searched PubMed, Embase, China Biomedical Literature Database (CBM), Cochrane library and clinical registration centre, identifying all randomised controlled trials (RCT) published in English and Chinese to 3 May 2022. A random-effect model was used to calculate the weighted mean difference (WMD) and 95 % CI. Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I 2 ). Statistical analyses were performed using STATA version 15.1. P-values < 0·05 were considered as statistically significant. From 2377 retrieved studies, fifteen studies were finally included in the meta-analyses. Fifteen RCT with 762 individuals were included in our meta-analysis. Compared with the control group, the supplementation of capsaicin resulted in significant reduction on BMI (WMD: -0·25 kg/m2, 95 % CI = -0·35, -0·15 kg/m2, P < 0·05), body weight (BW) (WMD: -0·51 kg, 95 % CI = -0·86, -0·15 kg, P < 0·05) and waist circumference (WC) (WMD: -1·12 cm, 95 % CI = -2·00, -0·24 cm, P < 0·05). We found no detrimental effect of capsaicin on waist-to-hip ratio (WMD: -0·05, 95 % CI = -0·17, 0·06, P > 0·05). The current meta-analysis suggests that capsaicin supplementation may have rather modest effects in reducing BMI, BW and WC for overweight or obese individuals.

Context, importance, and process for creating a body mass index surveillance system to monitor childhood obesity within the New York City public school setting

The Office of School Health, a joint program of the Departments of Health and Education, administers New York City’s (NYC) body mass index (BMI) surveillance system to monitor childhood obesity. We describe the context, importance, and process for creating a multi-agency, school-based BMI surveillance system using BMI collected from annual FITNESSGRAM® physical fitness assessments conducted as part of a larger physical activity and wellness curriculum in NYC public schools. We also summarize our current system and methodology, highlighting the types of data and data sources that comprise the system and partnership between the Departments of Health and Education that enable data sharing. Strategies for addressing threats to data quality, including missing data, biologically implausible values, and imprecise/subjective weight or height equipment are discussed. We also review current and future surveillance data products, and provide recommendations for collecting, analyzing, interpreting, and reporting BMI data for childhood obesity surveillance. Collaboration between Departments of Health and Education as well as attention to safeguards of BMI reporting and data quality threats have enabled NYC to collect high quality BMI data to accurately monitor childhood obesity trends. These findings have implications for youth BMI surveillance systems in the United States and globally.

Determination of Body Fat Ratio Standards in Children at Early School Age Using Bioelectric Impedance

Background and objectives: Body mass index (BMI) is commonly used to assess the proportionality of body mass; however, there are currently no standards for assessing the weight status of the child population for the needs of epidemiological studies. This study aims to establish bioelectric impedance analysis (BIA) standards for assessing the body weight of children (body fat, visceral fat) using BMI percentile growth charts. Materials and Methods: The study was implemented in a group of 1674 children (816 boys and 858 girls), ages 6 to 11. To classify the subjects at a percentile level, the percentile growth charts from the 6th national anthropological study in the Czech Republic were used. Body composition parameters were ascertained by BIA. Results: Body fat (%) and visceral fat standard values were determined for all age categories. The standards were in three-stages, enabling the determination of underweight, normal weight and overweight children aged 6-11 years. For boys with proportionate body mass, standard body fat values ranging from 14.3-16.0% to 15.5-18.0% were determined, while for girls' values ranging from 16.7-19.4% to 18.3-20.5% were determined, depending on age. As far as visceral fat is concerned, standard values in boys ranging from 30.3-36.9 cm2 to 36.1-44.9 cm2 and in girls 30.3-36.9 cm2 to 36.1-44.9 cm2 were determined, depending on age. Conclusions: Standards for assessing weight status are applicable to children aged 6-11 years, while it can be confirmed that BMI can be considered as an objective tool in assessing body mass and body composition in children.

Interactions between ambient air pollution and obesity on lung function in children: The Seven Northeastern Chinese Cities (SNEC) Study

Children are vulnerable to air pollution-induced lung function deficits, and the prevalence of obesity has been increasing in children. To evaluate the joint effects of long-term PM₁ (particulate matter with an aerodynamic diameter ≤ 1.0 μm) exposure and obesity on children's lung function, a cross-sectional sample of 6740 children (aged 7-14 years) was enrolled across seven northeastern Chinese cities from 2012 to 2013. Weight and lung function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), peak expiratory flow (PEF), and maximal mid-expiratory flow (MMEF), were measured according to standardized protocols. Average PM₁, PM_2.5, PM₁₀ and nitrogen dioxide (NO₂) exposure levels were estimated using a spatiotemporal model, and sulphur dioxide (SO₂) and ozone (O₃) exposure were estimated using data from municipal air monitoring stations. Two-level logistic regression and general linear models were used to analyze the joint effects of body mass index (BMI) and air pollutants. The results showed that long-term air pollution exposure was associated with lung function impairment and there were significant interactions with BMI. Associations were stronger among obese and overweight than normal weight participants (the adjusted odds ratios (95% confidence intervals) for PM₁ and lung function impairments in three increasing BMI categories were 1.50 (1.07-2.11) to 2.55 (1.59-4.07) for FVC < 85% predicted, 1.44 (1.03-2.01) to 2.51 (1.53-4.11) for FEV₁ < 85% predicted, 1.34 (0.97-1.84) to 2.04 (1.24-3.35) for PEF < 75% predicted, and 1.34 (1.01-1.78) to 1.93 (1.26-2.95) for MMEF < 75% predicted). Consistent results were detected in linear regression models for PM₁, PM_2.5 and SO₂ on FVC and FEV₁ impairments (P_Interaction < 0.05). These modification effects were stronger among females and older participants. These results can provide policy makers with more comprehensive information for to develop strategies for preventing air pollution induced children's lung function deficits among children.

Elementary school physical activity opportunities and physical fitness of students: A statewide cross-sectional study of schools

BACKGROUND

Using a cross-sectional design, we assessed the relationship between the time schools provide for physical activity and the proportion of students achieving a healthy aerobic capacity or body mass index.

METHODS

In 2013-2014, physical education and grade-level teachers from 905 of 1,244 Georgia elementary schools provided survey data about the frequency and duration of physical activity opportunities offered before, during, and after school. Log-binomial models related the weekly physical activity minutes provided by schools to the proportion of children in the FitnessGram healthy fitness zone for aerobic capacity or body mass index while adjusting for school characteristics and demographics.

RESULTS

During-school physical activity time was not associated with student fitness, but schools with before-school physical activity programs had a moderately higher prevalence of healthy aerobic capacity (prevalence ratio among girls: 1.06; 99% confidence interval: 1.00-1.13; prevalence ratio among boys: 1.03; 99% confidence interval: 0.99-1.08). Each additional 30 minutes of recess per week was associated with no more than a 3%-higher proportion of students with healthy body mass indexes (prevalence ratio among girls: 1.01; 99% confidence interval: 1.00-1.03; prevalence ratio among boys: 1.01; 99% confidence interval: 0.99-1.03).

CONCLUSIONS

The amount of physical activity time provided by schools is not strongly associated with school-aggregated student fitness. Future studies should be designed to assess the importance of school-based physical activity time on student fitness, relative to physical activity type and quality.

Relation Between Body Mass Index and Body Image in Spanish and Mexican Adolescents

This article aims to study the relation between Body Mass Index (BMI) and body image in adolescents from two different social environments in Spain and Mexico, and to compare the construction of an appropriate body scheme in youth from these two countries. The majority of participants were found to be in the normal weight category of BMI. No significant differences were found in BMI or body image comparing Mexican and Spanish adolescents. Regardless of the country of origin, youth belonging to the weight deficit category of BMI overestimated their body shape, whereas those pertaining to overweight and obesity categories underestimated it. Both over- and underestimating own body shape imply higher risk to suffer from behavioral and psychological distresses, such as eating disorders. Further research is recommended in order to analyze the social, educational, and emotional patterns related to this occurrence and to improve their quality of life.

Effect of Cardiorespiratory Fitness on Academic Achievement is Stronger in High-SES Elementary Schools Compared to Low

BACKGROUND

Academic achievement is influenced by factors at the student, school, and community levels. We estimated the effect of cardiorespiratory fitness performance on academic performance at the school level in Georgia elementary schools and examined effect modification by sociodemographic factors.

METHODS

This study is a repeat cross-sectional analysis of Georgia elementary schools between 2011 and 2014 (approximately 1138 schools per year). Multivariable beta regression estimated the effect of the proportion of 4th and 5th graders meeting cardiorespiratory fitness standards on the proportion of 5th graders passing standardized tests for Reading, English and Language Arts, Mathematics, Science, and Social Studies and considered potential interaction by school-level socioeconomic status (SES), racial composition, and urbanity.

RESULTS

There was a 0.15 higher estimated odds (OR: 1.15 (1.09, 1.22)) of passing the mathematics standardized test for every 10-percentage-point increase in school-level cardiorespiratory fitness among high-SES schools and 0.04 higher odds (OR: 1.04 (1.02, 1.05)) for low-SES schools. This pattern was similar for other academic subjects. No effect modification by racial composition or urbanity was observed for any academic subject.

CONCLUSIONS

Promoting physical fitness may be effective in improving academic performance among high-SES schools, but additional strategies may be needed among lower-SES schools.

Differences in childhood body mass index between lesbian/gay and bisexual and heterosexual female adolescents: A follow-back study

Objective

To determine whether childhood body mass index (BMI), assessed in childhood, differs between lesbian/gay and bisexual (LGB) and heterosexual late adolescents, and whether childhood social stressors impact the association between sexual orientation and childhood BMI.

Methods

Participants included 2,070 late adolescents from the Pittsburgh Girls Study, of whom 233 (11.2%) identified as lesbian or bisexual and 1,837 (88.8%) as heterosexual at ages 17–20 years. Weight and height were used to calculate body mass index (BMI) at ages 10 through 14 years. Data were collected on child reported loneliness at ages 8 to 10 and peer victimization from 10 to 14 years.

Results

LGB females had higher BMIs and greater increases in BMI from ages 10–14 years compared to heterosexual females and reported higher levels of loneliness and peer victimization in childhood. Loneliness moderated the association between sexual identity and changes in BMI; for participants with loneliness scores in the upper quartile, the increase in BMI over time was approximately 30% higher for LGB females compared to heterosexual females. Child report of peer victimization mediated the association between sexual identity and changes in BMI, with nearly 18% of the total effect of sexual identity on BMI over time accounted for by peer victimization.

Conclusions

Lesbian and bisexual adolescents report greater loneliness and peer victimization as children than heterosexual adolescents; these stressors confer risk for higher BMI among LGB females. These data underscore the importance of research on the social determinants of health. The hypothesis that the social stressors may partially account for differences in BMI and other cardiometabolic risk factors between LGB and heterosexual females should be addressed in future research.

Cutoff Points of BMI for Classification of Nutritional Status Using Bioelectrical Impedance Analysis

The objective of this study was to improve the cutoff points of the traditional classification of nutritional status and overweight / obesity based on the BMI in a Brazilian sample. A cross-sectional study was conducted on 1301 individuals of both genders aged 18 to 60 years. The subjects underwent measurement of weight and height and bioelectrical impedance analysis. Simple linear regression was used for statistical analysis, with the level of significance set at p < 0.05. The sample consisted of 29.7% men and 70.3% women aged on averaged 35.7 ± 17.6 years; mean weight was 67.6 ± 16.0 kg, mean height was 164.9 ± 9.5 cm, and mean BMI was 24.9 ± 5.5 kg/m². As expected, lower cutoffs were found for BMI than the classic reference points traditionally adopted by the WHO for the classification of obesity, i.e., 27.15 and 27.02 kg/m² for obesity for men and women, respectively. Other authors also follow this tendency, Romero-Corral et al. (2008) suggested 25.8 to 25.5 kg/m² for American men and women as new values for BMI classification of obesity. Gupta and Kapoor (2012) proposed 22.9 and 28.8 kg/m² for men and women of North India. The present investigation supports other literature studies which converge in reducing the BMI cutoff points for the classification of obesity. Thus, we emphasize the need to conduct similar studies for the purpose of defining these new in populations of different ethnicities.

Limitations of body mass index to assess body composition due to sarcopenic obesity during leukemia therapy

Obesity as defined by body mass index percentile (BMI%) is strongly associated with relapse and poorer survival in childhood ALL. Whether BMI% accurately reflects body fat percentage (BF%) in this population is unknown. We conducted a prospective study assessing body composition during frontline ALL therapy. Dual-energy X-ray absorptiometry measured BF% and lean muscle mass (LMM) at diagnosis, end of Induction, and end of Delayed Intensification. Sarcopenic obesity (gain in BF% with loss of LMM) was surprisingly common during ALL treatment, resulting in poor correlation between changes in BMI% (expressed as Z-score) and BF% overall (r = -0.05) and within patients (r = -0.09). BMI Z-score and BF% changed in opposite directions in >50% of interval assessments. While BMI% at diagnosis is a suitable predictor of obesity/BF% for epidemiological studies, change in BMI% (as expressed as Z-score) does not reflect body composition. Studies evaluating obesity in leukemia should consider using direct measures of body composition.

Fitness Trends and Disparities Among School-Aged Children in Georgia, 2011-2014

OBJECTIVES

Although FitnessGram fitness data on aerobic capacity and body mass index (BMI) have been collected in public schools in Georgia since the 2011-2012 school year, the data have not been analyzed. The primary objective of our study was to use these data to assess changes in fitness among school-aged children in Georgia between 2011 and 2014. A secondary objective was to determine if student fitness differed by school size and socioeconomic characteristics.

METHODS

FitnessGram classifies fitness into the Healthy Fitness Zone (HFZ) or not within the HFZ for aerobic capacity and BMI. We used data for 3 successive school years (ie, 2011-2012 to 2013-2014) obtained from FitnessGram testing of students in >1600 schools. We calculated the percentage of students who achieved the HFZ for aerobic capacity and BMI. We used growth curve models to estimate the annual changes in these proportions, and we determined the effect of school size and socioeconomic status on these changes.

RESULTS

Both elementary school boys (β = 1.31%, standard error [SE] = 0.23%, P < .001) and girls (β = 1.53%, SE = 0.26%, P < .001) had significant annual increases in achievement of HFZ for aerobic capacity. Elementary school boys (β = 3.11%, SE = 0.32%, P < .001) and girls (β = 3.09%, SE = 0.32%, P < .001) also had significant increases in their BMI HFZ achievement proportions, although these increases occurred primarily between 2011-2012 and 2012-2013. Body mass index HFZ achievement proportions were mixed for middle school students, and we did not observe increases for high school students. Larger school size and higher school socioeconomic status were associated with better aerobic capacity and BMI fitness profiles.

CONCLUSIONS

Surveillance results such as these may help inform the process of designing state and local school-based fitness promotion and public health programs and tracking the results of those programs.

The Intersections of Science and Practice: Examples From FitnessGram® Programming

The FitnessGram® program has provided teachers with practical tools to enhance physical education programming. A key to the success of the program has been the systematic application of science to practice. Strong research methods have been used to develop assessments and standards for use in physical education, but consideration has also been given to ensure that programming meets the needs of teachers, students, parents, and other stakeholders. This essay summarizes some of these complex and nuanced intersections between science and practice with the FitnessGram® program. The commentaries are organized into 5 brief themes: science informing practice; practice informing science; balancing science and practice; promoting evidence-based practice; and the integration of science and practice. The article draws on personal experiences with the FitnessGram® program and is prepared based on comments shared during the 37th Annual C. H. McCloy Research Lecture at the 2017 SHAPE America - Society of Health and Physical Educators Convention.

The Healthy Fitness Zone Continuum Score as a Measure of Change in Body Mass Index of School-Aged Children and Adolescents, Georgia, 2012-2014

OBJECTIVES

The FitnessGram Healthy Fitness Zone continuum (HFZc) score reflects the relative difference of a person's body mass index (BMI) from the established FitnessGram standard. As such, it may provide added utility for public health programming and research on obesity among school-aged children and adolescents. We used the standard BMI Z (BMIz) score and the alternative HFZc score to describe changes in BMI of school-aged children and adolescents in Georgia over time.

METHODS

We compiled 2012-2014 BMI data from the Georgia FitnessGram database. The sample included 162 992 boys and 141 711 girls enrolled in 239 schools from a large urban district in Georgia. We analyzed trends in BMIz and HFZc scores separately for normal-weight, overweight, and obese categories for school-aged children and adolescents using hierarchical linear models.

RESULTS

From 2012 to 2014, the BMIz score shifted favorably in up to 40.7% (2052/5047) of normal-weight, 51.0% (758/1485) of overweight, and 52.8% (5430/10 279) of obese students. We also found favorable shifts in HFZc score in up to 69.8% (105 831/151 739) of normal-weight, 78.3% (3605/4603) of overweight, and 80.8% (8305/10 279) of obese students.

CONCLUSIONS

Compared with the BMIz score, the HFZc score may be a better indicator of favorable changes in BMI over time among school-aged children and adolescents with different baseline BMI levels, making it potentially valuable for use in individualized assessments, school programs, obesity research, and public health curriculum and policy development.

Impact of NFL PLAY 60 Programming on Elementary School Children's Body Mass Index and Aerobic Capacity: The NFL PLAY 60 FitnessGram Partnership Project

BACKGROUND

We examined the impact of the Fuel Up to Play 60 (FUTP60) program on children's body mass index (BMI) and aerobic capacity (AC).

METHODS

Participation in the FUTP60 and both BMI and AC profiles were collected through the NFL PLAY 60 FitnessGram Partnership Project involving over 100 schools from 22 US states. We specifically examined the distributions of BMI and AC among participating versus nonparticipating schools in the 2012-2013 school year. Hierarchical linear models tested the impact of participation and availability of additional funding for program implementation on the proportions of youth meeting FitnessGram health-related fitness standards (ie, Needs Improvement-Health Risk [NIHR] and Healthy Fitness Zone [HFZ] categories).

RESULTS

After 1 year implementing the program, participating schools had lower proportions of boys (-4.1 ± 2.0%, p = .04) and girls (-4.5 ± 2.0%, p = .03) in the NIHR for BMI, and lower proportion of girls (-9.7 ± 4.0%, p = .02) in the NIHR for AC. There were no differences in the distributions for the HFZ and the availability of additional funding did not alter the relationships (p > .05).

CONCLUSIONS

This study provides preliminary evidence that participation in the FUTP60 is associated with improved profiles of health-related fitness.

School and Neighborhood Predictors of Physical Fitness in Elementary School Students

BACKGROUND

We assessed the associations of 5 school and 7 neighborhood variables with fifth-grade students achieving Healthy Fitness Zone (HFZ) or Needs Improvement-Health Risk (NI-HR) on aerobic capacity (AC) and body composition (BC) physical fitness components of the state-mandated FITNESSGRAM^® physical fitness test.

METHODS

Data for outcome (physical fitness) and predictor (school and neighborhood) variables were extracted from various databases (eg, Data Quest, Walk Score^® ) for 160 schools located in San Diego, California. Predictor variables that were at least moderately correlated (|r| ≥ .30) with ≥1 outcome variables in univariate analyses were retained for ordinary least squares regression analyses.

RESULTS

The mean percentages of students achieving HFZ AC (65.7%) and BC (63.5%) were similar (t = 1.13, p = .26), while those for NI-HR zones were significantly different (AC = 6.0% vs BC = 18.6%; t = 12.60, p < .001). Correlations were greater in magnitude for school than neighborhood demographics and stronger for BC than AC. The school variables free/reduced-price lunch (negative) and math achievement (positive) predicted fitness scores. Among neighborhood variables, percent Hispanic predicted failure of meeting the HFZ BC criterion.

CONCLUSIONS

Creating school and neighborhood environments conducive to promoting physical activity and improving fitness is warranted.

School and County Correlates Associated with Youth Body Mass Index

PURPOSE

The purpose of the study was to explore the utility of school- and county-level variables in explaining variability in children and adolescent body mass index (BMI).

METHODS

BMI data from nearly 2.5 million of children and adolescents were aggregated at the school level from more than 5000 schools in Texas. School-level predictors included enrollment and the percentage of students qualifying for free and reduced lunch. Seven county-level variables were obtained from the County Health Rankings website, including adult obesity, food environment index, adult physical inactivity, access to exercise, college completion, childhood poverty, and income inequality. Multilevel modeling was used to examine school- and county-level predictors that may explain the variability in group level youth BMI.

RESULTS

School-level socioeconomic status, school enrollment, and age-group were identified as significant predictors in youth BMI for both boy and girls. In girls, county-level adult obesity, food environment index, college completion, and income inequality were also significantly associated with youth BMI. In boys, the significant county-level predictors were food environment index and income inequality. Approximately 11%-16% of the variations in BMI Healthy Fitness Zone achievement were attributable to the differences between counties. The predictors included in the present study collectively explained approximately 50%-60% of between-county variation and 24%-47% of within-county variation.

CONCLUSIONS

The results of the current study advance research on the correlates that are associated with youth obesity at both school and county levels. These factors should be taken into account by policy makers and researchers interested in childhood obesity research.

Overweight or obesity associations with physical aggression in children and adolescents

Being overweight or obese (overweight/obesity) or physically aggressive in childhood and adolescence can have lifelong consequences, hence are important public health problems. Identifying a relationship between these problems would assist in understanding their developmental origins. The present paper sought to review previous studies and use meta-analysis to evaluate whether there is evidence of a relationship between overweight/obesity and physical aggression in children and adolescents. A systematic search of studies that reported the effect of overweight/obesity (in the form of body mass index) on physical aggression was conducted. A total of 23 studies were identified, representing data from 255,377 participants. The results indicate that children and adolescents who are overweight or obese are more physically aggressive than their normal-weight or underweight peers. The average weighted standardized mean difference (the effect size) for aggression in overweight and obese children and adolescents compared to others was found to be 0.27 (95% confidence interval [CI95]: .17–.37), and was significant ( p<.001). Gender sub-analysis indicated that higher physical aggression amongst overweight or obese compared to normal-weight or underweight peers is a slightly larger effect for boys (standardized mean difference of .35, CI95: .18–.52, p<.001) than girls (standardized mean difference of .24, CI95: .07–.42, p<.01). High levels of heterogeneity (94.41%) were found between study-level effect sizes. The developmental processes that may explain the association between overweight/obesity and physical aggression in children and adolescents are discussed.

Comparison of methods to measure body fat in 7-to-10-year-old children: a systematic review

OBJECTIVE

To investigate methodological aspects in body fat (BF) measurements in 7-to-10-year-old children.

STUDY DESIGN

Systematic review of the literature.

METHODS

The studies were chosen from the PubMed and Scielo databases according to a protocol that defined: inclusion criteria; a search and quality-assessment strategy; and information extraction.

RESULTS

27 studies published from 2004 to 2014 were included. The literature describes skinfold measurements and dual energy X-ray absorptiometry (DEXA) as being the reference methods most widely used in the assessment of the ability of methods to identify BF. The most commonly-used statistical analyses were the Pearson correlation coefficient, and sensitivity and specificity performance analyses. The comparison between the tested methods and the references showed that body mass index (BMI) and waist circumference (WC) are strongly correlated to BF as calculated by bioelectrical impedance or skinfolds, and that there is a moderate positive correlation with percent body fat as calculated by DEXA, air-displacement plethysmography (ADP) or isotope dilution. There was a moderate positive correlation between waist-to-height ratio (WHtR) and BF, as estimated by ADP and skinfolds. Performance studies suggest that BMI and WC are very specific but less sensitive methods.

CONCLUSIONS

The results of this systematic review show favourable evidence for the use of anthropometric indicators - above all BMI and WC- in the measurement of BF, when more accurate techniques such as DEXA and ADP are not feasible. They also demonstrate features that make them advantageous for epidemiological studies in a child population, since they are easy and safe to obtain and well tolerated by the children.

Establishing Waist-to-Height Ratio Standards from Criterion-Referenced BMI Using ROC Curves in Low-Income Children

The purpose of this study was to establish health-related waist-to-height ratio (WHtR) cut-points associating with FITNESSGRAM's body mass index (BMI) criterion-referenced standards in low-income children. A secondary aim was to examine the classification agreement between the derived WHtR cut-points and various cardiometabolic blood markers using current recommendations. Participants were 219 children from low-income schools (mean age = 10.5 ± 0.6 years). Waist circumference, height, weight, and cardiometabolic blood markers were collected in a fasting state before school hours. Receiver operating characteristic (ROC) curves were used to determine WHtR cut-points that associated with a child meeting FITNESSGRAM's age- and sex-specific criterion-referenced standards for BMI. The derived WHtR cut-point was 0.50 (AUC = 0.89, p < 0.001; sensitivity = 0.86, specificity = 0.82, and accuracy = 84.3%). Classification agreement using the derived WHtR cut-point with various blood marker standards was statistically significant but considered weak to fair (kappa 0.14-0.34, agreement = 59%-67%, and p < 0.01). The WHtR cut-point of 0.50 can be used with strong accuracy to distinguish low-income children who met FITNESSGRAM's criterion-referenced standards for body composition; however, the evidence was weaker for its use in distinguishing low-income children meeting specific cardiometabolic blood marker recommendations.

Weight-height relationships and central obesity in 7-year-old to 10-year-old Polish urban children: a comparison of different BMI and WHtR standards

Background

An increase in overweight and obesity rates among children is a major social problem; however, interpretation and comparability of estimations may be affected by the reference values and cut-off points used. The aim of the study was to assess the prevalence of underweight, overweight, obesity and central obesity in 7-year-old to 10-year-old urban children and to compare the results obtained through various standards of BMI or waist-to-height ratio (WHtR) indicators.

Methods

The research was conducted on a sample group of 367 girls and 424 boys aged 6.5–10.5 years, randomly chosen from a number of primary schools in Warsaw, Poland. In all participants, basic somatic features were assessed, and based on BMI and WHtR values, participants were then classified according to different standards. The prevalence of underweight, overweight, obesity and central obesity in boys and girls was compared using the chi-square test; fractions obtained from various BMI and WHtR standards were compared through a test for proportions; and the conformity of classification methods was assessed using Cohen’s kappa coefficient.

Results

Approximately 9 % of girls and 6 % of boys were underweight, 15 % of all participants was classified as overweight, and approximately 4 % of girls and 6 % of boys aged 7–10 were obese. Central obesity was diagnosed in 18.6–20.9 % of all participants, while another 7.1 % of girls and 7.5 % of boys displayed symptoms of excessive fat deposition characterized by elevated body fat percentages. Even though the prevalence estimations varied depending on the standards used, the overall classification compliance reached 86–94 % with a Cohen’s kappa coefficient ranging from 0.676 to 0.841.

Conclusion

The prevalence of underweight, overweight and obesity among urban children is comparable to estimates for the general population. Of particular concern, in terms of health and proper physical development, is the problem of central obesity that affects one out of five children. The use of reference values representing body fat percentage seems justified as it allows for a more precise diagnosis of weight-related disorders, including the particularly threatening abdominal obesity.

The effects of school physical education grants on obesity, fitness, and academic achievement

OBJECTIVE

Foundations and governments fund a number of programs that provide grants to improve school physical education or other forms of school-based physical activity. The effects of these grant programs are unknown. We evaluate the effects of Texas Fitness Now, a program in which the state of Texas granted $37 million to improve physical education in high-poverty middle schools over the 4 school years from 2007-08 to 2010-11. The stated goals of Texas Fitness Now were to reduce obesity, increase fitness, and raise academic achievement.

METHOD

We summarize how Texas Fitness Now funds were spent and estimate the impact of Texas Fitness Now using a fixed-effects longitudinal model that exploits changes in schools' eligibility over time. Changes in eligibility occurred when eligibility expanded to new schools after year 2 and when the program was terminated after year 4.

RESULTS

Most Texas Fitness Now funds were spent on sports and fitness equipment. Smaller amounts were spent on anti-obesity curricula. Texas Fitness Now improved strength and flexibility, especially among girls, but it did not improve BMI or academic achievement, and it had mixed effects on aerobic capacity. The fitness benefits were not lost in the year after the program ended, perhaps because schools kept the equipment that they had bought during their years of eligibility.

CONCLUSION

The results of Texas Fitness Now were typical for an intervention that relied almost exclusively on physical activity. Programs that improve BMI as well as fitness tend to have a more fully developed nutrition component.

Establishing Normative Reference Values for Standing Broad Jump Among Hungarian Youth

PURPOSE

The purpose of this study was to examine age and sex trends in anaerobic power assessed by a standing broad jump and to determine norm-referenced values for youth in Hungary.

METHOD

A sample of 2,427 Hungarian youth (1,360 boys and 1,067 girls) completed the standing broad jump twice, and the highest distance score was recorded. Quantile regression was used to fit standing broad jump trends across linear and quadratic functions of age. Statistical significance was determined with bootstrap confidence intervals and the Wald test with p < .05. Age-by-sex specific centiles were generated and the 50th percentile was used to describe the overall patterns.

RESULTS

Standing broad jump scores increased steadily in boys from age 11 through 18 years with a discrete plateau at the end of adolescence. Girls' standing broad jump scores of those who performed above the median increased with age and plateaued later in the adolescence. Both linear and quadratic age terms were statistically significant predictors of standing broad jump trends across age (p < .05), but the relations varied depending on the percentile. The 50th percentile values resulted in 147.0 cm, 162.0 cm, 175.0 cm, 186.0 cm, 195.0 cm, 202.0 cm, 207.0 cm, and 210.0 cm for boys aged 11 to 18 years old, respectively, and 140.0 cm, 143.9 cm, 147.3 cm, 150.0 cm, 152.1 cm, 153.7 cm, 154.6 cm, and 155.0 cm for girls aged 11 to 18 years old, respectively.

CONCLUSIONS

This study provides normative reference charts that take into account age and sex differences in standing broad jump performance. The proposed reference values can be used to interpret standing broad jump scores in Hungarian youth.

Establishing Normative Reference Values for Handgrip Among Hungarian Youth

PURPOSE

The purpose of this study was to examine age- and sex-related variation in handgrip strength and to determine reference values for the Hungarian population.

METHOD

A sample of 1,086 Hungary youth (aged 11-18 years old; 654 boys and 432 girls) completed a handgrip strength assessment using a handheld dynamometer. Quantile regression was used to compute separate models for boys and girls and included a linear, cubic, and quadratic term for age to account for nonlinear patterns. These terms were tested for statistical significance using the Wald statistical test with p < .05. Age- and sex-specific centiles were generated and the 50th percentile was used to describe the overall patterns in handgrip strength.

RESULTS

The linear, cubic, and quadratic terms for age fitted the data well for boys (p < .05), while both linear and quadratic terms for age were statistically significant for girls (p < .05). The 50th percentile values resulted in 21.4 kg, 21.7 kg, 25.0 kg, 30.0 kg, 35.4 kg, 40.0 kg, 42.6 kg, and 42.0 kg for boys aged 11 to 18 years old, respectively. The same percentile resulted in 20.0 kg, 19.5 kg, 19.6 kg, 20.3 kg, 21.6 kg, 23.5 kg, 26.1 kg, and 29.2 kg for girls aged 11 to 18 years old, respectively.

CONCLUSIONS

Muscle strength as determined by handgrip has distinct age-related patterns in boys and girls. We have accounted for biological age differences and developed norm-referenced values that can be used to interpret handgrip assessment scores obtained from school-aged children in Hungary.

Agreement and Diagnostic Performance of FITNESSGRAM®, International Obesity Task Force, and Hungarian National BMI Standards

PURPOSE

This study examined agreement between all 3 standards (as well as relative diagnostic associations with metabolic syndrome) using a representative sample of youth from the Hungarian National Youth Fitness Study.

METHOD

Body mass index (BMI) was assessed in a field sample of 2,352 adolescents (ages 10-18.5 years) and metabolic syndrome status was assessed in a laboratory subsample of 373 youth. All youth were categorized into weight status groups based on the FITNESSGRAM®, International Obesity Task Force (IOTF), and Hungarian growth standards. Classification agreement was compared between all pairs of standards via cross-tabulation. Logistic regression was used to estimate the odds of metabolic syndrome by weight status.

RESULTS

The 3 BMI standards agreed on ≥  88% of cases, with better agreement on girls' standards than boys' standards. Kappa values ranged from .65 to .89. Using the Hungarian standards over the Fitnessgram or IOTF standards resulted in 5% to 10% more youth being classified as normal weight. The overweight/obesity groups were 4 times to 6 times more likely to have metabolic syndrome than those classified as normal weight regardless of the classification standards. These odds ratios increased to 8 times to 17 times when comparing the normal-weight/overweight groups to the obesity category. Odds ratios for boys tended to be slightly larger than those for girls.

CONCLUSIONS

All 3 standards provide similar information about weight status and metabolic syndrome classification. To more easily facilitate international comparisons, it may be of greater benefit to use the IOTF standards, which also had better agreement with the U.S. Fitnessgram thresholds.

[Anthropometric indicators of obesity in the prediction of high body fat in adolescents]

OBJECTIVE:

To determine the anthropometric indicators of obesity in the prediction of high body fat in adolescents from a Brazilian State.

METHODS:

The study included 1,197 adolescents (15-17 years old). The following anthropometric measurements were collected: body mass (weight and height), waist circumference and skinfolds (triceps and medial calf). The anthropometric indicators analyzed were: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and conicity index (C-Index). Body fat percentage, estimated by the Slaughter et al equation, was used as the reference method. Descriptive statistics, U Mann-Whitney test, and ROC curve were used for data analysis.

RESULTS:

Of the four anthropometric indicators studied, BMI, WHtR and WC had the largest areas under the ROC curve in relation to relative high body fat in both genders. The cutoffs for boys and girls, respectively, associated with high body fat were BMI 22.7 and 20.1kg/m², WHtR 0.43 and 0.41, WC 75.7 and 67.7cm and C-Index 1.12 and 1.06.

CONCLUSIONS:

Anthropometric indicators can be used in screening for identification of body fat in adolescents, because they are simple, have low cost and are non-invasive.

[Low agreement between the fitnessgram criterion references for adolescents]

OBJECTIVE:

To analyze the association and agreement of fitnessgram reference criteria (RC) for cardiorespiratory fitness, body mass index (BMI) and strength in youth.

METHODS:

The study included 781 youth, 386 females, aged 10 to 18 years of Londrina-PR. It were performed cardiorespiratory fitness and muscular strength tests and was calculated body mass index. The association between the tests was analyzed using Poisson regression to obtain prevalence ratio (PR) and confidence intervals of 95%, while agreement of the reference criteria was tested by Kappa index.

RESULTS:

Significant associations were found between cardiorespiratory fitness and BMI (PR=1,49, 1,27-1,75), muscle strength and BMI (PR=1,55, 1,17-2,08), cardiorespiratory fitness and muscle strength (PR=1,81, 1,47-2,24). The agreement between reference criteria ranged from weak to fair, 48.8% (k=0.05, p=0.10) for cardiorespiratory fitness and BMI, 52.9% (k=0.09, p=0.001) for muscle strength and BMI and 38.4% (k=0.22, p<0.001) for cardiorespiratory fitness and muscle strength.

CONCLUSIONS:

Although RC for cardiorespiratory fitness, muscle strength and BMI are associated, the agreement between them ranged from weak to fair. To evaluate health related physical fitness it is suggest the execution of all tests, since each test has specific characteristics.

Geographical variation in health-related physical fitness and body composition among Chilean 8th graders: a nationally representative cross-sectional study

PURPOSE

In addition to excess adiposity, low cardiorespiratory fitness (CRF) and low musculoskeletal fitness (MSF) are important independent risk factors for future cardio-metabolic disease in adolescents, yet global fitness surveillance in adolescents is poor. The objective of this study was to describe and investigate geographical variation in levels of health-related physical fitness, including CRF, MSF, body mass index (BMI), and waist circumference (WC) in Chilean 8th graders.

METHODS

This cross-sectional study was based on a population-based, representative sample of 19,929 8th graders (median age = 14 years) in the 2011 National Physical Education Survey from Chile. CRF was assessed with the 20-meter shuttle run test, MSF with standing broad jump, and body composition with BMI and WC. Data were classified according to health-related standards. Prevalence of levels of health-related physical fitness was mapped for each of the four variables, and geographical variation was explored at the country level by region and in the Santiago Metropolitan Area by municipality.

RESULTS

Girls had significantly higher prevalence of unhealthy CRF, MSF, and BMI than boys (p<0.05). Overall, 26% of boys and 55% of girls had unhealthy CRF, 29% of boys and 35% of girls had unhealthy MSF, 29% of boys and 44% of girls had unhealthy BMI, and 31% of adolescents had unhealthy WC. High prevalence of unhealthy fitness levels concentrates in the northern and middle regions of the country and in the North and Southwest sectors for the Santiago Metropolitan Area.

CONCLUSION

Prevalence of unhealthy CRF, MSF, and BMI is relatively high among Chilean 8th graders, especially in girls, when compared with global estimates. Identification of geographical regions and municipalities with high prevalence of unhealthy physical fitness presents opportunity for targeted intervention.

Top 10 research questions related to growth and maturation of relevance to physical activity, performance, and fitness

Growth, maturation, and development dominate the daily lives of children and adolescents for approximately the first 2 decades of life. Growth and maturation are biological processes, while development is largely a behavioral process. The 3 processes occur simultaneously and interact. They can be influenced by physical activity and also can influence activity, performance, and fitness. Allowing for these potential interactions, 10 questions on growth and maturation that have relevance to physical activity, performance, and fitness are presented. The questions are not mutually exclusive and address several broadly defined topical areas: exercise and growth, body weight status (body mass index, adiposity rebound, "unhealthy weight gain"), movement proficiency (hypothesized barrier, role in obesity), individual differences, tracking, maturity-associated variation in performance, and corresponding variation in physical activity. Central to the discussion of each is the need for a biocultural approach recognizing the interactions of biology and behavior as potential influences on the variables of interest.

Diagnostic performance of BMI percentiles to identify adolescents with metabolic syndrome

OBJECTIVES

To compare the diagnostic performance of the Centers for Disease Control and Prevention (CDC) and FITNESSGRAM (FGram) BMI standards for quantifying metabolic risk in youth.

METHODS

Adolescents in the NHANES (n = 3385) were measured for anthropometric variables and metabolic risk factors. BMI percentiles were calculated, and youth were categorized by weight status (using CDC and FGram thresholds). Participants were also categorized by presence or absence of metabolic syndrome. The CDC and FGram standards were compared by prevalence of metabolic abnormalities, various diagnostic criteria, and odds of metabolic syndrome. Receiver operating characteristic curves were also created to identify optimal BMI percentiles to detect metabolic syndrome.

RESULTS

The prevalence of metabolic syndrome in obese youth was 19% to 35%, compared with <2% in the normal-weight groups. The odds of metabolic syndrome for obese boys and girls were 46 to 67 and 19 to 22 times greater, respectively, than for normal-weight youth. The receiver operating characteristic analyses identified optimal thresholds similar to the CDC standards for boys and the FGram standards for girls. Overall, BMI thresholds were more strongly associated with metabolic syndrome in boys than in girls.

CONCLUSIONS

Both the CDC and FGram standards are predictive of metabolic syndrome. The diagnostic utility of the CDC thresholds outperformed the FGram values for boys, whereas FGram standards were slightly better thresholds for girls. The use of a common set of thresholds for school and clinical applications would provide advantages for public health and clinical research and practice.

Effect of a park-based after-school program on participant obesity-related health outcomes

PURPOSE

The objective of this study was to examine the effect of a structured after-school program housed in a large county parks system on participant health and wellness outcomes.

DESIGN

Longitudinal cohort study over one school year (fall 2011-spring 2012).

SETTING

A total of 23 county parks in Florida.

SUBJECTS

Children ages 5 to 16 (N = 349, 55% non-Hispanic black, 40% Hispanic, mean age 8.9 years).

INTERVENTION

An after-school program called Fit-2-Play that integrates daily standardized physical activity and health and wellness education components.

MEASURES

Preintervention (August/September 2011) and postintervention (May/June 2012) anthropometric, systolic/diastolic blood pressure, fitness, and health and wellness knowledge measurements were collected.

ANALYSIS

Comparison of pre-post outcome measure means were assessed via general linear mixed models for normal-weight (body mass index [BMI] <85th percentile for age and sex) and overweight/obese (BMI ≥85th percentile for age and sex) participants.

RESULTS

The overweight/obese group significantly decreased their mean (1) BMI z score (2.0 to 1.8, p < .01) and (2) subscapular skinfold measurements (19.4 to 17.5 mm, p < .01) and increased (1) mean laps on the Progressive Aerobic Cardiovascular Endurance Run test (10.8 to 12.5, p = .04) and (2) percentage with normal systolic blood pressure (58.1% to 71.0%, p = .03) from pretest to posttest. On average, participants significantly improved their health and wellness knowledge over the school year (p < .01). Normal-weight participants maintained healthy BMI ranges and significantly increased fitness levels.

CONCLUSION

Findings suggest that the Fit-2-Play after-school programs can be a significant resource for combating childhood obesity and instilling positive physical health in children, particularly among ethnic and socioeconomically diverse communities.

Field assessments for obesity prevention in children and adults: physical activity, fitness, and body composition

Nutrition and health educators work in community settings implementing lifestyle programs focused on obesity prevention and chronic disease risk reduction. These programs typically focus on improving diet and physical activity (PA) behaviors. Many nutrition educators may not be confident in their ability to select, administer, and interpret PA assessments to effectively evaluate their PA or lifestyle programs. This report will assist educators in identifying and selecting appropriate field-based assessments for measurement of PA, physical fitness, and body composition for children and adults. Specific guidelines, references, and resources are given for selecting assessment methods and test within these 3 areas.

Assessing early growth and adiposity: report from an EarlyNutrition Academy workshop

This report provides a summary of a workshop organised by the European Commission-funded EarlyNutrition Project and the EarlyNutrition Academy. Accurate and reliable methods to assess body composition are needed in research on prenatal and early post-natal influences of nutrition on later health because common surrogate measures of maternal and offspring adiposity (body fat content), such as body mass index (BMI), have relatively poor predictive power for the risk of later disease. The key goals of the workshop were to discuss approaches to assess growth and body composition from pregnancy to adolescence, to summarise conclusions and to prepare a framework for research in the EarlyNutrition Project. The participants concluded that there is a pressing need to harmonise the methodologies for assessing body composition, recognising that each has advantages and limitations. Essential core measurements across studies assessing early growth and body composition were identified, including weight, length, BMI, waist and mid-upper arm circumference, subscapular and triceps skinfold thicknesses, and bioelectrical impedance analysis. In research settings with access to more sophisticated technologies, additional methods could include dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, ultrasound assessment of regional body fat, magnetic resonance imaging (MRI), air displacement plethysmography (ADP), and deuterium dilution. These provide richer data to answer research questions in greater depth but also increase costs. Where overall whole-body composition is the primary outcome measure, ADP or tracer dilution should be used whenever possible. Where regional distribution of body fat is of greater interest, an imaging technique such as MRI is preferred.

Indices of abdominal adiposity and cardiorespiratory fitness test performance in middle-school students

BACKGROUND

Previous research suggests that use of BMI as a screening tool to assess health in youth has limitations. Valid alternative measures to assess body composition are needed to accurately identify children who are aerobically fit, which is an indicator of health status. The purpose of this study was to examine the associations between select anthropometric measures and cardiorespiratory fitness test performance in middle-school students.

METHODS

Participants included 134 students (65 boys and 69 girls) recruited from the 6th, 7th, and 8th grades. Anthropometric measures consisted of BMI, waist circumference (WC), waist-to-height ratio (WHtR), and percent body fat estimated from two-site skinfolds (%BF-SKF), as well as the hand-held OMRON BIA device (%BF-BIA). Cardiorespiratory fitness tests included the one-mile run and PACER test. Data were collected on four separate testing days during the students' physical education classes.

RESULTS

There were statistically significant moderate correlations between the %BF estimations, WHtR, and cardiorespiratory fitness test scores in both genders (P < .001). BMI at best only displayed weak correlations with the cardiorespiratory fitness test scores.

CONCLUSIONS

The results suggest that alternative measures such as %BF-SKF, %BF-BIA, and WHtR may be more valid indicators of youth aerobic fitness lending to their preferred use over BMI.

Obesity and motor skills among 4 to 6-year-old children in the United States: nationally-representative surveys

BACKGROUND

Few population-based studies have assessed relationships between body weight and motor skills in young children. Our objective was to estimate the association between obesity and motor skills at 4 years and 5-6 years of age in the United States. We used repeated cross-sectional assessments of the national sample from the Early Childhood Longitudinal Survey-Birth Cohort (ECLS-B) of preschool 4-year-old children (2005-2006; n = 5 100) and 5-6-year-old kindergarteners (2006-2007; n = 4 700). Height, weight, and fine and gross motor skills were assessed objectively via direct standardized procedures. We used categorical and continuous measures of body weight status, including obesity (Body Mass Index (BMI) ≥ 95th percentile) and BMI z-scores. Multivariate logistic and linear models estimated the association between obesity and gross and fine motor skills in very young children adjusting for individual, social, and economic characteristics and parental involvement.

RESULTS

The prevalence of obesity was about 15%. The relationship between motor skills and obesity varied across types of skills. For hopping, obese boys and girls had significantly lower scores, 20% lower in obese preschoolers and 10% lower in obese kindergarteners than normal weight counterparts, p < 0.01. Obese girls could jump 1.6-1.7 inches shorter than normal weight peers (p < 0.01). Other gross motor skills and fine motor skills of young children were not consistently related to BMI z-scores and obesity.

CONCLUSIONS

Based on objective assessment of children's motor skills and body weight and a full adjustment for confounding covariates, we find no reduction in overall coordination and fine motor skills in obese young children. Motor skills are adversely associated with childhood obesity only for skills most directly related to body weight.

Field evaluation of the new FITNESSGRAM® criterion-referenced standards

BACKGROUND

The Cooper Institute established new criterion-referenced standards for the body composition and cardiovascular fitness standards for the FITNESSGRAM(®) program.

PURPOSE

The purpose of this study was to evaluate differences in the achievement of standards and classification agreement between the old and new standards.

METHODS

Fitness data were collected during the 2009-2010 school year from 1686 youth (grades 3-12) from six schools (two districts) in a small Midwestern town. Data analyses were completed during the 2010 and 2011 school year. Descriptive statistics were computed to determine the percentage of students classified into the various fitness classifications using both the old and new standards. Classification agreement was examined for alternative tests of cardiovascular fitness (Progressive Aerobic Cardiovascular Endurance Run [PACER] and 1-mile run) and body composition (skinfold determination of body fat and BMI) using both the old and new standards.

RESULTS

The descriptive results reveal important age and gender differences in reported levels of fitness levels in school-aged youth. For body composition, the percentage of youth achieving the healthy fitness zone (HFZ) was about 10% lower with the new standards than the old ones. For aerobic capacity, a larger percentage of young boys and a smaller percentage of older boys achieved the new HFZ for aerobic capacity. However, a smaller percentage of girls achieved the new HFZ at all ages. The use of test-equating in the revised standards led to significant improvements in the classification agreement between 1-mile run and the PACER.

CONCLUSIONS

The large data set provided a useful sample to examine the impact of the new fitness standards on the documentation of youth fitness levels in schools. The new standards address a number of measurement issues with the old standards and provide a more appropriate way to evaluate levels of health-related fitness in youth.