Anthropometric body fat composition reference values in Spanish adolescents. The AVENA Study

Reference growth curves to identify weight status (underweight, overweight or obesity) in children and adolescents: systematic review

The identification of somatic growth, through reference curves, can be used to create strategies and public policies to reduce public health problems such as malnutrition and obesity and to identify underweight, overweight and obesity. The purpose of this systematic review was to identify studies providing reference growth curves for weight status in children and adolescents. A systematic search was conducted in eight databases and in gray literature (Google scholar). To assess the risk of bias/methodological quality of studies, the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-sectional Studies (NHLBI) was used. Overall, 86 studies that met the inclusion criteria were included. Through the values   of reference growth curves for the identification of underweight, overweight and obesity, it was possible to verify that there is great variability among percentiles for the identification of underweight, overweight and obesity. The most prevalent percentiles for underweight were P3 and P5; for overweight, the most prevalent was P85 and the most prevalent percentiles for obesity were P95 and P97. The most prevalent anthropometric indicators were Body Mass Index (BMI), Waist Circumference (WC), Body Mass (BM) for age and height for age. Conclusion: Such data can demonstrate that the optimal growth must be reached, through the standard growth curves, but that the reference curves demonstrate a cut of the population growth, raising possible variables that can influence the optimal growth, such as an increase in the practice of physical activities and an awareness of proper nutrition.

Physical Fitness-Not Physical Activity Levels-Influence Quality of Life in Anorexia Nervosa

Background: Incorporating physical activity (PA) has been a challenge for health care professionals working with anorexia nervosa (AN) patients. This has contributed to partial physical fitness (PFit) recovery that persists after weight restoration. Objective: This cross-sectional study aimed to examine the relationships between PA, sedentary behaviors, PFit, and quality of life (QoL) in a group of adolescents after hospitalization. Methods: QoL, PA, and sedentary behaviors were measured using the Health-Questionnaire Short-Form 36 (SF-36) and accelerometers, while PFit was assessed through cardiorespiratory fitness, body composition (anthropometry), and strength (six repetition maximum) tests in a total of 63 patients. Results: Light-PA (LPA), moderate-PA (MPA), moderate-to-vigorous-PA (MVPA), and relative sedentary time (%ST) did not meet the recommendations (p < 0.001). Only 22% of the patients met MVPA criteria, and ~82% exceeded %ST. SF-36 scores were lower than normative values except the physical component scale. Absolute cardiorespiratory fitness was reduced (p < 0.001) in 84% of the patients, and was positively associated to body weight, body mass index (BMI), circumferences, and muscle areas. Additional positive significant relationships were found between QoL, muscular strength, and body composition, and negative associations between vigorous-to-very vigorous PA and BMI, skinfolds, and percent body fat. Regression analyses revealed lower body strength as an explanatory factor for improved QoL (OR 1.03, 95%CI 1.00−1.07). Conclusions: PFit and QoL scores are poor after hospitalization. LPA, MPA, and MVPA do not meet recommendations. PFit management—with emphasis on improving muscular fitness—may be a valuable strategy for QoL improvement in AN after hospitalization.

Impact of SARS-CoV-2 Lockdown on Anthropometric Parameters in Children 11/12 Years Old

BACKGROUND

During the great lockdown in Spain due to SARS-CoV-2, in between the months of March and June 2020, dietary and physical activity habits were modified in children. The aim of the study was to determine the impact of the lockdown on anthropometric parameters in children aged 11/12 years.

METHODS

Fifty Spanish children aged 11/12 years (M = 11.40; SD = 0.50) participated: 33 (66%) boys and 17 (34%) girls. For data collection, we used an anthropometry kit; the Alpha-Fitness Battery, a validated instrument to assess dietary intake, habits and practices; and an ad hoc survey to collect sociodemographic and other data under investigation.

RESULTS

There were significant differences in the anthropometric parameters measured and in the results obtained for Body Mass Index (BMI) and body fat percentage pre- and post-lockdown in both boys and girls (p < 0.05). No significant differences were found in waist-circumference measurements (p > 0.05).

CONCLUSIONS

There is evidence of a significant impact of the SARS-CoV-2 lockdown on anthropometric parameters in boys and girls aged 11/12 years.

Physical growth of children and adolescents living at a moderate altitude: proposed percentiles based on age and sex

INTRODUCTION

physical growth patterns and nutritional status of children and adolescents living at moderate altitude are not applicable for clinical assessment of growth for diverse populations around the world.

OBJECTIVE

a) to compare weight, height and body mass index (BMI) variables with CDC-2012 references; b) to verify if BMI and/or ponderal index (PI) are applicable to children living at moderate altitude; and c) to propose percentiles to assess physical growth by age and sex.

METHODS

a total of 5,377 students, ranging in age from 6.0 to 17.9 years, were evaluated. The students were from two geographic regions of moderate altitude in Peru (2,320 meters) and Colombia (2,640 meters). Weight and height were measured. BMI and PI were calculated. Weight, height and BMI were compared with CDC-2012 references.

RESULTS

males showed lower weight and height from age 11 to 17.9 years compared to CDC-2012. Females weighed less than the reference from 9.0 to 17.9 years. Female height was lower from 6.0 to 14.9 years; however, from 15.0 to 17.9 years, values were similar to the reference. As for BMI, there were differences in both sexes (in males, from 15.0 to 17.9 years, and in females, from 12.0 to 17.9 years). Age, weight and height explained BMI: between R2 = 17 and 83 % in males, and in females between R2 = 24 and 85 %. These same variables influenced PI in a lower percentage in both sexes: for males (R2 = 0.01 to 49 %) and for females (R2 = 0.01 to 18 %).

CONCLUSIONS

children and adolescents living at moderate altitude in Peru and Colombia diverge from the CDC-2012 physical growth patterns. In addition, PI is a new alternative for estimating weight in relation to BMI. The proposed curves for weight, height, and PI by age and sex could have greater implications in the control of child health programs and in clinical and epidemiological practices.

Leuconostoc mesenteroides subsp. mesenteroides SD23 Prevents Metabolic Dysfunction Associated with High-Fat Diet-Induced Obesity in Male Mice

High-fat diet (HFD) consumption induces obesity and increases blood glucose, insulin resistance, and metabolic disorders. Recent studies suggest that probiotics might be a novel approach to counteract these effects in the treatment of obesity. Here, we evaluated the effect of Leuconostoc mesenteroides subsp. mesenteroides SD23 on obesity-related metabolic dysfunction. In the present study, mice were randomly divided into four dietary groups: standard diet (C), HFD (OB), standard diet with L. mesenteroides SD23 (CP), and HFD with L. mesenteroides SD23 (OBP). Diets were maintained for 14 weeks. Animal weight was monitored and biochemical and histological analyses were performed after intervention. OB showed metabolic dysfunction, and increased the number of larger adipocytes compared to C. OB induced liver tumor necrosis factor-α (TNF-α) expression, increased cholesterol, leptin, and glucose levels compared to C. OBP reduced body weight, glucose, cholesterol, and leptin levels and improved glucose tolerance compared to OB. OBP also reduced liver steatosis, the number of larger adipocytes in adipose tissue, and reduced the villus height in the small intestine. OBP decreased expression of TNF-α and increased expression of IL-10 in liver. The parameters evaluated in the CP were similar to the C. This study provides novel evidence that dietary intervention with L. mesenteroides SD23 improves metabolic dysfunction related to obesity in HFD-fed mice.

Temporal trend of cardiorespiratory endurance in urban Catalan high school students over a 20 year period

Background

Physical fitness is considered an important indicator of health in adolescents. However, in recent years several studies in the scientific literature have shown a considerable lower trend and an alarming worsening of the current adolescents’ physical condition when comparing with previous decades, especially in urban populations. The aim of the current study was to analyse the temporal trend in cardiorespiratory endurance (CRE) in urban Catalan adolescents over a 20-year period (1999–2019).

Methods

A cross-sectional analysis study considering the 20-m Shuttle Run test (SRT) results obtained in the last 20 years was carried out. 1,701 adolescents between 15 and 16 years old (914 boys and 787 girls) were divided into four groups, corresponding to consecutive periods of five years (Group 1: 1999–2004; Group 2: 2005–2009; Group 3: 2010–2014 and Group 4: 2015–2019). ANOVA was used to test the period effect on CRE and post hoc Bonferroni analysis was performed to test pairwise differences between groups (p < 0.05).

Results

Results showed a significantly lower performance in CRE in both sexes. The percentual negative difference was 0.67%, 9.6% and 7% for boys and 5.06%, 14.97% and 9.41% for girls, when comparing the performance in 20-m Shuttle Run test for the first period, respectively.

Conclusions

Results suggest that the physical fitness of Catalan urban adolescents is lower in both sexes when comparing the different analysed periods of time. Therefore, CRE adolescents should be improved in order to help to protect against cardiovascular disease and other health risks in adulthood.

Development and Cross-Validation of a Prediction Equation for Estimating Percentage Body Fat From Body Mass Index in Young People With Intellectual Disability

The purpose of this study was to develop and cross-validate an equation for estimating percentage body fat (%BF) from body mass index and other potential independent variables among young persons with intellectual disability. Participants were 128 persons with intellectual disability (62 women; age 16-24 years) split between development (n = 98) and cross-validation (n = 30) samples. Dual-energy X-ray absorptiometry served as the reference method for %BF. An equation including 1/body mass index and sex (0 = male; 1 = female) was highly accurate in estimating %BF (p < .001; R2 = .82; standard error of estimate = 5.22%). Mean absolute and root mean square errors were small (3.1% and 3.9%, respectively). A Bland-Altman plot indicated nearly zero mean difference between actual and predicted %BF with modest 95% confidence intervals. The prediction equation was %BF = 56.708 - (729.200 × [1/body mass index]) + (12.134 × sex). Health care professionals may use the prediction equation for monitoring %BF among young people with intellectual disability.

PUBERTY IN A SAMPLE OF BRAZILIAN SCHOOLBOYS: ONSET AND ANTHROPOMETRIC CHARACTERISTICS

Objective:

To determine the age of puberty onset in boys and collect anthropometric data of participants at different puberty stages.

Methods:

This is a cross-sectional study that assessed 430 boys in a random sample representing 48,390 students from public and private schools from the city of Uberaba, Southeast Brazil. The inclusion criteria were males, aged between 5 and 18 years, and absence of previous diseases. Participants and their guardians filled a semistructured questionnaire with questions relevant to their and their parents’ puberty. We set the significance at p<0.05 and calculated the 95% confidence intervals.

Results:

The mean age found in the puberty stage G2 was 11.2±1.8 (95% of participants in stage G2 were 9.2-13.4 years old). Pubarche data showed a mean of age of 11.0±1.6 years (95% of the participants experienced pubarche when they were 8.0-14.0 years old). When compared to the confidence intervals of two classical studies on the subject, our results showed a trend toward earlier pubarche. In addition, the mean age of this event in the children’s parents was of 12.1±1.4 years, which was significantly higher than the age of the children’s pubarche (p<0.001).

Conclusions:

These results indicate a secular decreasing trend in pubarche age and an earlier puberty onset. Considering these parameters, is important to design public policies aimed at preventing these early events.

Identifying early abdominal obesity risk in adolescents by telemedicine: A cross-sectional study in Greece

Obesity and thus, lipotoxicity, is a major health risk factor. Modern exposure to environmental chemicals has contributed significantly to the obesity epidemic. The purpose of this study was to assess, via telemedicine and using bioelectrical impedance analysis (BIA) in schools, the levels of adiposity and other body composition parameters of Greek adolescents in relation with their metabolic syndrome (MetS) characteristics. A representative sample (1575 adolescents, 14.4 ± 1.7 years-old) of the Attica region population, underwent body composition assessment of fat mass (FM), fat-free mass (FFM), and total body water (TBW) and was evaluated for anthropometric and MetS characteristics. Males demonstrated higher FFM% and TBW% but lower FM% than females. Adolescents with abdominal obesity/MetS (n = 149/n = 40) demonstrated significantly (P < 0.001) higher body mass index (BMI 27.8 ± 3.8 kg/m²/30.2 ± 4.2 kg/m²) and FM (33.6 ± 9.7%/35.0 ± 10.5%) but significantly (P < 0.001) lower FFM (34.2 ± 5.7%/33.8 ± 6.2%) and TBW (45.6 ± 6.7%/44.6 ± 7.2%) than adolescents without abdominal obesity/MetS (BMI 20.9 ± 2.8 kg/m²/21.3 ± 3.2 kg/m²; FM 19.2 ± 6.9%/20.2 ± 8.0%; FFM 41.3 ± 4.4%/40.8 ± 4.8%; TBW 55.5 ± 4.8%/54.8 ± 5.5%). Findings suggest that early "osteosarcopenic" elements of abdominal obesity/MetS may exist even in adolescence. The application of BIA, incorporated in the new approach methodology of telemedicine in schools, identified adolescents at risk for obesity complications.

Relationship between Adherence to the Mediterranean Diet and Body Composition with Physical Fitness Parameters in a Young Active Population

The current study aimed at analyzing the relationship between body composition, adherence to the Mediterranean diet (MD), and physical fitness (PF) in a young active population. A total of 1198 athletes (boys = 875; girls = 323) enrolled in different municipal sports schools participated in this study. Data on adherence to the MD (KIDMED questionnaire), anthropometric measurements, and PF (20 m shuttle run test, handgrip strength, vertical jump and forced spirometry) were collected. Results show that the pubertal boys had a higher score in the KIDMED test than the prepubertal ones (+0.38, p = 0.28). Moreover, boys with better adherence to the MD had significantly higher results in handgrip strength (+12.20 regarding low MD group and +9.13 regarding medium MD group, p < 0.05), as well as in forced vital capacity (FVC) (+0.66 regarding low MD group and 0.29 regarding medium MD group, p < 0.05). No differences were found in the girls. Finally, the result of the KIDMED test is a variable with a positive and significant relationship with cardiorespiratory fitness, along with the FVC, percentage of fat mass, and performance in the vertical jump (p < 0.05). It is concluded that adherence to the MD could show a relationship with various PF variables in boys and could be a predictor of cardiorespiratory fitness in both cases.

Prediction of body fat in Sri Lankan adults: Development and validation of a skinfold thickness equation

OBJECTIVE

The study aimed to develop and validate a percentage body fat (%BF) prediction equation using SFT for Sri Lankan adults.

METHODS

Healthy adults (≥18 years) were randomly selected and SFT was measured in five areas (triceps, biceps, calf, suprailliac and subscapular). Body composition analysis was evaluated by Deuterium oxide (D₂O) dilution. Prediction equation for %BF was derived by linear-regression-analysis.

RESULTS

Study population included 170 adults (Males: 32.9%; age: 43.2 ± 12.6 years). Final equation for %BF (r = 0.715, p < 0.001) correlated significantly D₂O dilution derived %BF.

CONCLUSIONS

The equation is suitable for estimation of %BF in Sri Lankan adults and is possibly appropriate for other South-Asian populations.

Association between Adherence to the Mediterranean Diet and Physical Fitness with Body Composition Parameters in 1717 European Adolescents: The AdolesHealth Study

Obesity, low levels of physical fitness, and unhealthy eating patterns are responsible for part of the health problems of adolescents today. The current study aimed at examining the association between the adherence to the Mediterranean diet (MD), through each answer to the items of the Adherence to the MD Questionnaire (KIDMED), and physical fitness with body composition parameters (body mass index (BMI), percentage of body fat, and waist circumference) in 1717 European adolescents (N = 900 boys, N = 817 girls). Data of body composition, physical fitness results, and the answers to KIDMED were analyzed by the Student’s t-test. Additionally, the effect size (ES) was calculated and a Chi-square test analyzed the proportion of participants with and without over waist circumference, overfat, and overweight in each KIDMED question. The relative risk of suffering over waist circumference, overfat and overweight in relation to the responses was calculated by Odd-Ratio. Adherence to the MD did not influence the condition of over waist circumference, overfat and overweight, although certain dietary habits were identified as risk factors for their development. Over waist circumference, overfat, and overweight boys and girls presented higher levels of body mass, waist circumference, body fat percentage, and BMI (p < 0.001; ES = 1.73–3.38), as well as lower levels of all the parameters of the physical fitness analyzed (p < 0.001; ES = 0.45–1.08), except the handgrip test. A direct relationship between fitness and over waist circumference, overfat, and overweight was found.

Evaluation of Physical Fitness, Body Composition, and Adherence to Mediterranean Diet in Adolescents from Estonia: The AdolesHealth Study

Unhealthy lifestyles, low levels of physical fitness, and adherence to the Mediterranean diet (MD) are associated with bad quality of life and the development of a wide range of non-communicable diseases (NCDs). The current study aimed to evaluate the level of adherence to the MD in physical fitness performance and body composition parameters in children and adolescents of Estonia. Therefore, 413 adolescents (56% boys) from the city of Tartu completed the Mediterranean Diet Questionnaire (KIDMED) for analyzing the adherence to MD and performed the Alpha Fitness Test for measuring physical fitness and body composition. A 41.67% of low, 44.05% of average, and 14.28% of high adherence to MD was detected, without difference between genders (p = 0.747). In the Alpha Fitness battery, a higher performance was observed in all tests for boys vs. girls (p < 0.05). In relation to body composition, higher height, weight, and waist values were observed in boys (p < 0.05) and a lower body fat percentage (p < 0.01) without differences in body mass index (BMI; p = 0.906). The adherence to the MD is classified as average/low. Gender significantly influences all variables of the Alpha Fitness battery and anthropometrics measures excepting BMI. According the levels of adherence to the MD, no statistically different prevalence was observed for Non-Overweight (N-O_weight), Non-Overfat (N-O_fat), or Non-Overwaist (N-O_waist). Still, a risk factor for Overweight (O_weight) in boys with low adherence was observed in comparison to those with a mid-level of adherence to the MD.

Mediterranean Diet, Physical Fitness and Body Composition in Sevillian Adolescents: A Healthy Lifestyle

Childhood and adolescent obesity has become one of the most vital challenges to overcome in the present age. Physical fitness, physical activity and the Mediterranean diet (MD) are valuable tools for its prevention and treatment. The main objective of this study is to analyze the associations between health-related physical fitness components, body composition and adherence to the MD in 917 adolescents aged from 13- to 16-years-old. The ALPHA-Fitness Test was used to measure physical fitness and body composition, and the Adherence to the Mediterranean Diet (KIDMED) questionnaire was employed to assess the adherence to the MD. The associations between variables were tested according to gender and age a generalized linear model (GLM) univariate analysis (two factors) and one-way analysis of variance (ANOVA, with Bonferroni posthoc). As to the body composition and physical fitness variables, significant differences were obtained in both genders but not in relation to the adherence to the MD. The boys performed better in the physical fitness tests. Age was a determinant factor in adherence to the MD in the total sample, lowering as the age of the sample increases. Both the boys and girls who had a significantly higher performance in the endurance test were those who showed high/medium adherence to the MD. It is concluded that higher levels of cardiovascular endurance in boys and girls are associated with a medium and high adherence to the MD.

Physical Growth and Body Adiposity Curves in Students of the Maule Region (Chile)

Objectives: Physical growth and body adiposity patterns provide relevant information to infer the nutritional and health status of students. Our objectives were (a) to compare the variables of body adiposity and physical growth of Chilean children and adolescents with data from the CDC-2012 and international studies, and (b) to develop regional reference curves to evaluate growth and body adiposity. Methods: 8,261 children and adolescents were studied. We evaluated the weight, height, and waist circumference (WC). The Body Mass Index (BMI) was calculated. Their physical growth and body adiposity were compared with the CDC-2012 references as well as with other international references. Percentile curves for weight, height, BMI, and WC were constructed with the LMS method. Results: The Chilean students showed reduced weight and height during adolescence when compared with the CDC-2012 reference. During early ages, the BMI for the Chilean sample was lower while at advanced ages, the WC values were greater in comparison to the CDC-2012 reference. Graphic comparisons with international studies indicated that Chilean students weighed more at all ages. However, height was slightly greater until age 14 for males and age 11 for females. Body adiposity (BMI and WC) for the Chilean students was slightly higher at early ages while at later ages, adiposity values were relatively similar for both sexes. Conclusions: Discrepancies were observed between the physical growth and body adiposity trajectories and the American CDC-2012 references and the international studies. The proposed percentiles for weight, height, BMI, and WC for each age and sex may be useful for health sciences professionals and researchers.

Adaptation and Validation of the Hydration Status Questionnaire in a Spanish Adolescent-Young Population: A Cross Sectional Study

The achievement of adequate hydration status is essential for mental and physical performance and for health in general, especially in children and adolescents. Nevertheless, little is known about hydration status of this population, mainly due to the limited availability of research tools; thus, the objective of the current study was to adapt and validate our hydration status questionnaire in a Spanish adolescent-young population. The questionnaire was validated against important hydration markers: urine colour, urine specific gravity, haemoglobin, haematocrit and total body water and involved 128 subjects aged between 12⁻17 years. Water intake was also estimated through a three-day dietary record and physical activity was assessed through accelerometers. Participants completed the questionnaire twice. Water balance and water intake were correlated with urine specific gravity and with total body water content. Water intake obtained by the questionnaire was correlated with results from the three-day dietary record. The intraclass correlation coefficient indicated moderate concordance between both recordings and the Cronbach's alpha revealed high consistency. The Bland and Altman method indicated that the limits of agreement were acceptable to reveal the reliability of the estimated measures. In conclusion, this is the first time that a questionnaire is valid and reliable to estimate hydration status of adolescent-young populations.

Prevalence of overweight and obesity and associated factors in school children and adolescents in a medium-sized Brazilian city

OBJECTIVES

The objective of this study was to describe the prevalence of overweight and obesity in school children and adolescents in a medium-sized Brazilian city.

METHODS

In total, 1,125 children and adolescents between the ages of 5.6 and 18 years from public and private schools participated in the study. The sample included 681 girls and 444 boys. Each subject's weight and height were obtained according to Brazilian guidelines (SISVAN). The triceps (TSF), subscapular (SSF), biceps, suprailiac, femoral and calf skinfolds were measured in triplicate. Body mass index (BMI) was classified as the BMI percentile (BMIP) according to the World Health Organization (WHO) 2007 criteria. The percentage body fat (%BF) was obtained using the equations by Slaughter et al., 1998. Categorical variables were analyzed using the chi-squared test.

RESULTS

Overall, 364 participants with excess weight were identified: 17.3% were overweight, and 15.0% were obese. Among the girls, 18.0% were overweight, and 12.5% were obese; among the boys, 15.3% were overweight, and 18.0% were obese. These prevalence rates were higher when the time spent watching TV or participating in media-related activities surpassed 5 hrs/day, when individuals belonged to a higher economic class and when the head of the family had a higher education level (≥12 years).

CONCLUSION

It is important to emphasize the need to increase our understanding of factors associated with overweight and obesity, and it is essential to implement measures and policies aimed at reversing this trend, such as stimulating healthy eating habits and physical activity and reducing time spent watching TV and participating in other media activities, including video games and social networking.

Healthy Lifestyle: Relationship between Mediterranean Diet, Body Composition and Physical Fitness in 13 to 16-Years Old Icelandic Students

Childhood and adolescent obesity are currently among the greatest challenges for public health. Physical activity, physical fitness, and adherence to the Mediterranean diet (MD), representing powerful indicators of healthy lifestyles, are shown as determinant factors in the prevention and treatment of obesity. The aim of the present study has been to analyse the relationship between health-related physical fitness components, body composition, and adherence to MD in 387 Icelandic adolescents of 13⁻16-years old (54% boys). The ALPHA Fitness Test was used to measure physical fitness and body composition. The KIDMED questionnaire was used to assess the adherence to MD among participants. Associations between variables were tested according to gender and age using linear regression models and analysis of variance. Participants with high/medium adherence to MD showed significantly higher endurance scores in both the boys and the girls. Gender differences were found. The boys in high/medium MD categories had significantly lower fat percentages and ran a 4 × 10 m sprint faster than the girls. The girls scored higher than the boys in endurance and speed-agility tests. It can be concluded that a high and medium adherence to MD is associated with high and very high endurance in both the girls and the boys.

Diet quality index as a predictor of treatment efficacy in overweight and obese adolescents: The EVASYON study

BACKGROUND & AIM

A diet quality index (DQI) is a tool that provides an overall score of an individual's dietary intake when assessing compliance with food-based dietary guidelines. A number of DQIs have emerged, albeit their associations with health-related outcomes are debated. The aim of the present study was to assess whether adherence to dietary intervention, and the overall quality of the diet, can predict body composition changes.

METHODS

To this purpose, overweight/obese adolescents (n = 117, aged: 13-16 years; 51 males, 66 females) were recruited into a multi-component (diet, physical activity and psychological support) family-based group treatment programme. We measured the adolescents' compliance and body composition at baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up. Also, at baseline, after 6 months, and at the end of follow-up we calculated the DQI.

RESULTS

Global compliance with the dietary intervention was 37.4% during the intensive phase, and 14.3% during the extensive phase. Physical activity compliance was 94.1% at 2-months and 34.7% at 13months and psychological support compliance were growing over the intervention period (10.3% intensive phase and 45.3% during extensive phase). Adolescents complying with the meal frequency criteria at the end of the extensive phase had greater reductions in FMI z-scores than those did not complying (Cohen's d = 0.53). A statistically significant association was observed with the diet quality index. DQI-A variation explained 98.1% of BMI z-score changes and 95.1% of FMI changes.

CONCLUSIONS

We conclude that assessment of changes in diet quality could be a useful tool in predicting body composition changes in obese adolescents involved in a diet and physical activity intervention programme backed-up by psychological and family support.

Assessment of physical activity levels, fitness and perceived barriers to physical activity practice in adolescents: cross-sectional study

Adolescence is a time of rapid physical, psychological and social changes. Recent studies show that, at this stage, there is a decrease in physical activity (PA) levels, along with high rates of overweight and obesity. The purpose of this study was to assess PA levels and physical condition (PC) related to perceived barriers (PB) and limiting factors for PA practice in a randomised sample of adolescents in Barcelona (Spain) considering overweight status and gender. One hundred and forty-three adolescents (53.8 % boys; median age of 15 years) of Secondary Education in public schools located in a randomly selected district (Sants - Montjuïc) in Barcelona (Spain) participated in a cross-sectional study. Variables assessed were (a) PC (ALPHA-Fitness), (b) PA levels (Physical Activity Questionnaire PAQ-A), and (c) perceived barriers (Self-Reported Barriers to Participation in Physical Activity questionnaire). The different variables were tested by calculating means and standard deviations, with the presence/absence of overweight, and according to the adolescents' gender. Means between groups were compared using Student's t test.

CONCLUSION

Significant differences in most results suggest a correlation between being overweight or obese and having a worse PC. The variables gender (being a girl) and body mass index (overweight or obese) showed a direct correlation to perceive significantly greater barriers to PA practice. What is known: • Epidemiological studies indicate that there is a high prevalence of overweight and obesity linked to an insufficient amount of physical activity (PA) practice in children and adolescents, which is accompanied higher rates of abandonment of the common PA practice as they grow up. • Perceived barriers to regular PA practice had increased in the adolescent population, accompanied with lower levels of PA practice. What is new: • This study shows for the first time the correlation between physical condition, PA levels, and perceived barriers to regular PA, considering overweight and gender. • There is a correlation between being overweight or obese and having a worse physical condition. The variables gender (being a girl) and body mass index (overweight or obese) showed a direct correlation to perceive significantly greater barriers to PA practice.

Physical fitness and anthropometric normative values among Colombian-Indian schoolchildren

Background

Substantial evidence indicates that children’s physical fitness levels are markers of their lifestyles and their cardio-metabolic health profile and are predictors of the future risk of chronic diseases such as obesity, cardiometabolic disease, skeletal health and mental health. However, fitness reference values for ethnic children and adolescents have not been published in a Latin-American population. Therefore, the aim of the study was to provide sex- and age-specific physical fitness and anthropometric reference standards among Colombian-Indian schoolchildren.

Methods

A sample of 576 participants (319 boys and 257 girls) aged 10 to 17 years old was assessed using the FUPRECOL test battery. Four components of physical fitness were measured: 1) morphological component: height, weight, body mass index (BMI), waist circumference (WC), triceps skinfold, subscapular skinfold, and body fat (%); 2) musculoskeletal component: handgrip and standing long jump test; 3) motor component: speed/agility test (4 × 10 m shuttle run); and 4) cardiorespiratory component: course-navette 20 m, shuttle run test and estimation of maximal oxygen consumption by VO₂max indirect. Centile smoothed curves for the 3^rd, 10^th, 25^th, 50^th, 75^th, 90^th and 97^th percentiles were calculated using Cole’s LMS method.

Results

Our results show that weight, height and BMI in each age group were higher in boys than in girls. In each groups, age showed a significant effect for BMI and WC. Boys showed better than girls in cardiorespiratory fitness, lower- and upper-limb strength and speed/agility and girls performed better in low back flexibility.

Conclusion

Our results provide for the first time sex- and age-specific physical fitness and anthropometric reference values for Colombian Nasa Indian children and adolescents aged 10–17.9 years.

Puberty in a sample of Brazilian schoolgirls: timing and anthropometric characteristics

OBJECTIVE

The objective of this study was to determine the age at which puberty begins, age of menarche and anthropometric data of the participants at different stages of puberty.

SUBJECTS AND METHODS

This is a cross-sectional study in which we evaluated 665 girls, a sample representing the female schoolchildren population in Uberaba.

RESULTS

We found that thelarche, pubarche, underarm hair and menarche were attained at the age of 9.8 ± 1.4, 10.2 ± 1.4, 10.5 ± 1.5 and 11.7 ± 1.3 years, respectively. The mean interval between thelarche and menarche (ITM) was 1.7 ± 1.3 years. The prevalence of overweight and obesity was 31.3% and 95% of the participants began at thelarche between the age of 7 and 12 years.

CONCLUSION

These values indicate a secular tendency to the decrease of the age of menarche and an earlier start of puberty. It is very important to understand these parameters to establish public policies aimed at plans to prevent these early events, especially regarding control of the prevalence of obesity.

Peripheral blood mononuclear cell gene expression profile in obese boys who followed a moderate energy-restricted diet: differences between high and low responders at baseline and after the intervention

The present study analyses the gene expression profile of peripheral blood mononuclear cells (PBMC) from obese boys. The aims of the present study were to identify baseline differences between low responders (LR) and high responders (HR) after 10 weeks of a moderate energy-restricted dietary intervention, and to compare the gene expression profile between the baseline and the endpoint of the nutritional intervention. Spanish obese boys (age 10–14 years) were advised to follow a 10-week moderate energy-restricted diet. Participants were classified into two groups based on the association between the response to the nutritional intervention and the changes in BMI standard deviation score (BMI-SDS): HR group (n 6), who had a more decreased BMI-SDS; LR group (n 6), who either maintained or had an even increased BMI-SDS. The expression of 28 869 genes was analysed in PBMC from both groups at baseline and after the nutritional intervention, using the Affymetrix Human Gene 1.1 ST 24-Array plate microarray. At baseline, the HR group showed a lower expression of inflammation and immune response-related pathways, which suggests that the LR group could have a more developed pro-inflammatory phenotype. Concomitantly, LEPR and SIRPB1 genes were highly expressed in the LR group, indicating a tendency towards an impaired immune response and leptin resistance. Moreover, the moderate energy-restricted diet was able to down-regulate the inflammatory ‘mitogen-activated protein kinase signalling pathway’ in the HR group, as well as some inflammatory genes (AREG and TNFAIP3). The present study confirms that changes in the gene expression profile of PBMC in obese boys may help to understand the weight-loss response. However, further research is required to confirm these findings.

Arm anthropometry indices in Turkish children and adolescents: changes over a three-year period

OBJECTIVE

Time-related changes and comparisons for mid-upper arm circumference (MUAC), triceps skinfold thickness (TSF), arm fat area (AFA) are lacking for Turkish children and adolescents. To determine the arm anthropometry indices (MUAC, TSF, AFA) in children and adolescents and to also assess the changes in these indices over a 3-year time period.

METHODS

The data of the Anthropometry of Turkish Children Aged 0-6 Years (ATCA-06) study and the Second Study of Determination of the Anthropometric Measurements of Turkish Children and Adolescents (DAMTCA-II) were used to calculate the arm anthropometry percentiles in a total group of 6982 children and adolescents aged 28 days to 17 years. The 3rd-97th percentiles were computed by the LMS method.

RESULTS

In girls, 50th percentile MUAC values linearly increased with age. In boys, 50th percentile TSF values linearly increased until 10 years of age and decreased after age 11 years, while in girls, TSF values increased linearly with age. 50th percentile values for AFA showed a linear increase in both genders with age. Significant differences were found between the 5th, 50th and 95th percentile values for MUAC and AFA obtained in the two studies (DAMTCA-II and DAMTCA-I) in both boys and girls.

CONCLUSIONS

The prominent finding was the significant and alarming increase in arm anthropometry indices in both genders within as short period of time as three years.

Decreased cardiotrophin-1 levels are associated with a lower risk of developing the metabolic syndrome in overweight/obese children after a weight loss program

OBJECTIVE

Cardiotrophin-1 (CT-1) shares some similarities with other cytokines, and participates in the control of energy metabolism. Higher circulating levels are observed in obese humans, but little information is gathered in weight loss (WL) programs. Therefore, we aimed to investigate the association of serum CT-1 levels with metabolic variables and the risk of developing metabolic syndrome (MetS) after a WL program in overweight/obese children.

SUBJECTS AND METHODS

Forty-four overweight/obese children (mean age 11.5 y; 50% males) undergoing a 10-week WL program were enrolled. Subjects were dichotomized at the median of Body Mass Index-Standard Deviation Score (BMI-SDS) change, as high and low responders after intervention.

RESULTS

CT-1 levels were significantly reduced (-48 fmol/mL, p=0.043) in the high responder group after the WL program. They had significantly lower body weight (-3.7 kg, p<0.001), body fat mass (-8%, p<0.001), BMI-SDS (-0.78, p<0.001) and waist circumference (-5.4 cm, p<0.001), and a significant improvement in lipid and glucose profiles (p<0.05). Interestingly, decreased CT-1 levels significantly predicted changes in total cholesterol (41%) and LDL-cholesterol (28%). Moreover, in our participants the lower the CT-1 levels, the higher the reduction in MetS risk components, after the 10-week intervention, (p-ANCOVA=0.040, p-trend=0.024).

CONCLUSION

We showed, for the first time, a reduction in serum CT-1 levels after a WL program and this decrease in CT-1 was strongly associated with a reduction in cholesterol levels and in MetS risk factors in overweight/obese children. Our findings may suggest that CT-1 could be an indirect marker for the diagnosis of MetS in this population.

Impaired paraoxonase-1 status in obese children. Relationships with insulin resistance and metabolic syndrome

OBJECTIVES

To investigate the relationships between serum paraoxonase-1 (PON1), insulin resistance, and metabolic syndrome (MetS) in childhood obesity.

DESIGN AND METHODS

We studied 110 obese children and 36 non-obese children with a similar gender and age distribution. We measured serum PON1 activity against 5-thiobutyl butyrolactone (TBBLase) and against paraoxon (paraoxonase). PON1 concentration was measured separately as were the levels of several standard metabolic variables. The homeostasis model assessment (HOMA) index was calculated as an estimate of insulin resistance.

RESULTS

TBBLase was significantly decreased in obese children (P=0.008), while paraoxonase activity and PON1 concentrations showed non-significant trends towards decrease and increase, respectively (P=0.054 and P=0.060). TBBLase and paraoxonase specific activities were significantly decreased (P=0.004 and P=0.018, respectively). TBBLase specific activity was inversely associated with BMI, percentage body fat, insulin, HOMA, triglycerides, and C-reactive protein, and directly associated with HDL-cholesterol. Paraoxonase specific activity showed similar associations with BMI, percentage fat, HDL-cholesterol, and C-reactive protein. Obese children with MetS had lower TBBLase activities than obese children without MetS (P=0.018). Linear regression analyses showed that TBBLase was independently associated with HDL-cholesterol, BMI, percentage body fat and PON155 polymorphism, but paraoxonase activity was associated only with PON1192 polymorphism.

CONCLUSIONS

Our results suggest that PON1 may play a role in the onset and development of metabolic alterations in childhood obesity leading to diabetes and cardiovascular disease later in life. However, being derived from statistical association study, this finding cannot be seen as showing cause-effect.

Physique and body composition in soccer players across adolescence

Purpose

Although the contribution of physique and body composition in soccer performance was recognized, these parameters of physical fitness were not well-studied in adolescent players. Aim of this study was to investigate physique and body composition across adolescence.

Methods

Male adolescents (N=297 aged 12.01–20.98 y), classified into nine one-year age-groups, child (control group, N=16 aged 7.34–11.97 y) and adult players (control group, N=29 aged 21.01–31.59 y), all members of competitive soccer clubs, performed a series of anthropometric measures (body mass, height, skinfolds, circumferences and girths), from which body mass index (BMI), percentage of body fat (BF%), fat mass (FM), fat free mass (FFM) and somatotype (Heath-Carter method) were calculated.

Results

Age had a positive association with FM (r=0.2, P<0.001) and FFM (r=0.68, P<0.001), and a negative association with BF (r=−0.12, P=0.047). Somatotype components changed across adolescence as well; age was linked to endomorphy (r=−0.17, P=0.005), mesomorphy (r=0.14, P=0.019) and ectomorphy (r=−0.17, P=0.004). Compared with age-matched general population, participants exhibited equal body mass, higher stature, lower body mass index and lower BF.

Conclusion

During adolescence, soccer players presented significant differences in terms of body composition and physique. Thus, these findings could be employed by coaches and fitness trainers engaged in soccer training in the context of physical fitness assessment and talent identification.

Bacteroides uniformis CECT 7771 ameliorates metabolic and immunological dysfunction in mice with high-fat-diet induced obesity

BACKGROUND

Associations have been made between obesity and reduced intestinal numbers of members of the phylum Bacteroidetes, but there is no direct evidence of the role these bacteria play in obesity. Herein, the effects of Bacteroides uniformis CECT 7771 on obesity-related metabolic and immune alterations have been evaluated.

METHODS AND FINDINGS

Adult (6-8 week) male wild-type C57BL-6 mice were fed a standard diet or a high-fat-diet HFD to induce obesity, supplemented or not with B. uniformis CECT 7771 for seven weeks. Animal weight was monitored and histologic, biochemical, immunocompetent cell functions, and features of the faecal microbiota were analysed after intervention. The oral administration of B. uniformis CECT 7771 reduced body weight gain, liver steatosis and liver cholesterol and triglyceride concentrations and increased small adipocyte numbers in HFD-fed mice. The strain also reduced serum cholesterol, triglyceride, glucose, insulin and leptin levels, and improved oral tolerance to glucose in HFD fed mice. The bacterial strain also reduced dietary fat absorption, as indicated by the reduced number of fat micelles detected in enterocytes. Moreover, B. uniformis CECT 7771 improved immune defence mechanisms, impaired in obesity. HFD-induced obesity led to a decrease in TNF-α production by peritoneal macrophages stimulated with LPS, conversely, the administration of B. uniformis CECT 7771 increased TNF-α production and phagocytosis. Administering this strain also increased TNF-α production by dendritic cells (DCs) in response to LPS stimulation, which was significantly reduced by HFD. B. uniformis CECT 7771 also restored the capacity of DCs to induce a T-cell proliferation response, which was impaired in obese mice. HFD induced marked changes in gut microbiota composition, which were partially restored by the intervention.

CONCLUSIONS

Altogether, the findings indicate that administration of B. uniformis CECT 7771 ameliorates HFD-induced metabolic and immune dysfunction associated with intestinal dysbiosis in obese mice.

Body fat percentiles for German children and adolescents

OBJECTIVE

The aim of this study was to define body fat percentiles for German children and adolescents aged 3-16 years using the largest German database.

METHODS

The study population included 11,632 girls and 11,604 boys. Data were pooled from: i) Kiel Obesity Prevention Study (KOPS), acquisition period: 1996-2008, n = 12,237; ii) 'Better diet. More exercise. KINDERLEICHT-REGIONS', acquisition period: 2007, n = 9,405; and iii) examination of Jena schoolchildren, acquisition period: 2005, n = 1,594. Body fat mass was measured by bioelectrical impedance analysis using a population-specific algorithm. Data were weighted to achieve a representative sample for Germany. Percentile curves were constructed by the LMS method and proved by Worm plots and Q-statistic.

RESULTS

In both genders, the higher body fat percentile curves sloped downwards to age 7 years, whereas the lower percentiles declined up to 8.5 years. Thereafter fat mass remained nearly constant with age in boys and increased in girls. The 10th percentile achieved a minimum of 10-11% body fat in both genders, whereas the 90th percentile curve fluctuated between 29 and 44% in boys or 30-43% in girls. The association between fat mass and blood pressure was too weak to define disease-related cut-offs.

CONCLUSION

These body fat percentiles are suitable reference values for German children and adolescents.

Body fat percentile curves for U.S. children and adolescents

BACKGROUND

To date, several studies have been published outlining reference percentiles for BMI in children and adolescents. In contrast, there are limited reference data on percent body fat (%BF) in U.S. youth.

PURPOSE

The purpose of this study was to derive smoothed percentile curves for %BF in a nationally representative sample of U.S. children and adolescents.

METHODS

Percent fat was derived from the skinfold thicknesses of those aged 5-18 years from three cross-sectional waves of the National Health and Nutrition Examination Survey (NHANES) IV (1999-2000, 2001-2002, and 2003-2004; N=8269). The LMS (L=skewness, M=median, and S=coefficient of variation) regression method was used to create age- and gender-specific smoothed percentile curves of %BF.

RESULTS

Growth curves are similar between boys and girls until age 9 years. However, whereas %BF peaks for boys at about age 11 years, it continues to increase for girls throughout adolescence. Median %BF at age 18 years is 17.0% and 27.8% for boys and girls, respectively.

CONCLUSIONS

Growth charts and LMS values based on a nationally representative sample of U.S. children and adolescents are provided so that future research can identify appropriate cut-off values based on health-related outcomes. These percentiles are based on skinfolds, which are widely available and commonly used. Using %BF instead of BMI may offer additional information in epidemiologic research, fitness assessment, and clinical settings.

Fat and lean masses in youths with Down syndrome: gender differences

The present study aimed at comparing fat and lean masses between children and adolescents with and without Down syndrome (DS) and evaluating the presence of sexual dimorphism. Total and regional fat and lean masses were assessed by dual energy X-ray absorptiometry (DXA) and the percentage of body fat (%BF) by air-displacement plethysmography (ADP) in 31 participants with DS and 32 controls. Waist circumference (WC) was also measured. Analysis of covariance and the Student's t-test were used to compare variables between groups and between sexes within the same group. There were no significant differences in %BF, WC or body mass index (BMI) between groups. Females with DS showed higher fat and lean masses in the trunk, and lower fat and lean masses in the lower limbs compared with females without DS (all p≤0.05). Males with DS showed higher fat masses in the whole body and upper limbs, and lower lean masses in the whole body and lower limbs compared with males without DS (all p≤0.05). Females in both groups showed higher levels of fat, and lower levels of lean than did their respective males (all p≤0.05). Youths with DS showed higher fat and lower lean than their non-DS peers. The increased truncal fat in females with DS might indicate a higher risk of metabolic syndrome in this group. Sexual dimorphism in youths with and without DS was very similar. BMI, WC and %BF were not effective indicators of increased risk in youths with DS.

Changes in cardiometabolic risk factors, appetite-controlling hormones and cytokines after a treatment program in overweight adolescents: preliminary findings from the EVASYON study

OBJECTIVE

We investigated the effects of the EVASYON program on body fatness, cardiometabolic risk factors, gut appetite-controlling hormones and serum levels of cytokines in adolescents with overweight or obesity (OW/OB).

METHODS

This study comprised 13 boys (10 obese) and 12 girls (8 obese), aged 13-16 years, from a Madrid Hospital. The EVASYON program was based on a calorie-restricted diet (10-40%), increased physical activity (at least 60 min/day 5 days a week), psychological therapy and nutritional education for 13 months. Anthropometric and blood pressure measurements were measured before and after intervention. Serum glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, leptin, total peptide YY and insulin levels were determined before and after intervention. Serum levels of cytokines IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and TNF-α were also assessed before and after intervention.

RESULTS

A decrease in body mass index (BMI), BMI z-score, skinfolds (triceps, biceps, subscapular, thigh, and calf), sum of six skinfolds and body circumferences (arm relaxed and flexed, waist, hip, and proximal thigh) values were observed after the intervention program (all p < 0.05). In addition, diastolic blood pressure also decreased (p < 0.05). A decrease in serum leptin levels (-48.4%, p < 0.001) was observed after intervention without changes in total peptide YY and insulin levels. Levels of IL-8, IL-10, and TNF-α also decreased (all p < 0.05) after the intervention program.

CONCLUSIONS

These preliminary results evidence that the EVASYON program may improve body fat, leptin, and some pro-inflammatory cytokines in adolescents with OW/OB.

Design and results of the pretest of the IDEFICS study

BACKGROUND

During the preparatory phase of the baseline survey of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study, standardised survey procedures including instruments, examinations, methods, biological sampling and software tools were developed and pretested for their feasibility, robustness and acceptability.

METHODS

A pretest was conducted of full survey procedures in 119 children aged 2-9 years in nine European survey centres (N(per centre)=4-27, mean 13.22). Novel techniques such as ultrasound measurements to assess subcutaneous fat and bone health, heart rate monitors combined with accelerometers and sensory taste perception tests were used.

RESULTS

Biological sampling, physical examinations, sensory taste perception tests, parental questionnaire and medical interview required only minor amendments, whereas physical fitness tests required major adaptations. Callipers for skinfold measurements were favoured over ultrasonography, as the latter showed only a low-to-modest agreement with calliper measurements (correlation coefficients of r=-0.22 and r=0.67 for all children). The combination of accelerometers with heart rate monitors was feasible in school children only. Implementation of the computer-based 24-h dietary recall required a complex and intensive developmental stage. It was combined with the assessment of school meals, which was changed after the pretest from portion weighing to the more feasible observation of the consumed portion size per child. The inclusion of heel ultrasonometry as an indicator of bone stiffness was the most important amendment after the pretest.

DISCUSSION

Feasibility and acceptability of all procedures had to be balanced against their scientific value. Extensive pretesting, training and subsequent refinement of the methods were necessary to assess the feasibility of all instruments and procedures in routine fieldwork and to exchange or modify procedures that would otherwise give invalid or misleading results.

Body fat assessment in Sri Lankan adolescent girls; development of a simple field tool

BACKGROUND

Development of accurate, simple measures of body fat is essential in developing countries due to the rising prevalence of overweight and obesity. Application of skin-fold thickness (SFT) to body fat prediction equations is an inexpensive method suitable for field settings.

AIM

To determine percentage fat mass (%FM) of Sri Lankan adolescent girls using Fourier Transform Infrared spectrometry (FTIR) as a reference method and develop a SFT-prediction equation to estimate %FM.

METHODS

Weight, height and SFT were measured and %FM determined by FTIR in 131 adolescent, post-menarcheal girls (15-19 years). SFT-measurements were applied to available body composition equations for validation in the population. A new equation for %FM was derived and validated.

RESULTS

Mean %FM (FTIR) was 19.13 ± 8.2.Selected body composition prediction equations over-estimated %FM. The multiple regression procedure yielded a final equation consisting of two anthropometric and one demographic variable, % FM = 9.701 - (0.460)* age+(0.640)*TricepsSFT+(0.583)*Supra-iliacSFT.

CONCLUSIONS

Existing SFT prediction-equations are unsuitable for predicting %FM in this population. The new equation utilizing one peripheral and one truncal skin-fold, is appropriate for prediction of %FM in this population and may be applicable to other South Asian/Asian-Indian adolescents following validation.

Validity of body mass index and waist circumference to detect excess fat mass in children aged 7-14 years

BACKGROUND/OBJECTIVES

To evaluate the screening performance of body mass index (BMI) and waist circumference (WC) for excess adiposity. In addition, the diagnostic accuracy of cutoffs from different international and national reference systems based on BMI and WC was investigated.

SUBJECTS/METHODS

Data from 2132 Jena children aged 7-14 years conducted in 2005/2006 were analyzed. Receiver operating characteristic (ROC) curves were constructed to assess BMI and WC, as screening measures for excess adiposity (derived from skinfolds). Sensitivity, specificity and positive predictive values (PPVs) were calculated for two BMI-based classification systems (IOTF and German reference) and sample-based WC cutoffs.

RESULTS

The BMI as well as the WC performed well in detecting excess fat mass, indicated by areas under the ROC curve (AUC) close to 1.0, with slightly greater AUCs for BMI than for WC in both sexes. The specificity of all reference systems was high for both sexes (95 to 98%). However, their sensitivities were low (53-67% in boys; 51-67% in girls). PPV were higher for the German reference and the sample-based WC cutoffs than for the IOTF reference, and higher in girls than in boys.

CONCLUSIONS

The setting in which the reference system should be used is important for the selection of the reference system. The results support the use of the BMI-based references for monitoring in epidemiological studies. The sample-based cutoffs for WC should be refined for clinical use on national level.

Body mass index percentiles for children and adolescents in Germany based on a nationally representative sample (KiGGS 2003-2006)

OBJECTIVE

To present body mass index (BMI) percentiles representative for children in Germany and to compare them with the currently used percentiles by Kromeyer-Hauschild (KH) and international percentiles of the World Health Organisation (WHO) and the International Obesity Task Force (IOTF).

METHODS

Representative examination survey of 17 641 children and adolescents aged 0-17 years living in Germany (KiGGS 2003-2006 study, response rate 67%) with standardized measurement of height and weight.

RESULTS

Generally, BMI in KiGGS was higher than in the reference populations from previous decades. KiGGS shows an asymmetric upward shift of the BMI distribution from about age 6 years and an earlier adiposity rebound compared with KH. The BMI peak in the first year of life is shown by KiGGS and WHO, but much less by KH. The cut-offs for overweight and obesity determined with the IOTF methodology in KiGGS (percentiles corresponding to BMI 25 and 30 kg/m(2) at 18 years of age) were similar to IOTF cut-offs from age 18 to 10 years but systematically lower for younger children.

CONCLUSIONS

The KiGGS BMI percentiles appear more valid for Germany than present alternatives and should be used for population monitoring. Despite their methodological limitations, the general shape of the older German KH references is confirmed by KiGGS for the ages 2-17 years. In order not to obscure the increase in obesity rates in the last decades, we therefore propose to continue using KH for individual diagnosis and estimation of the prevalence of overweight and obesity in this age range.

Interplay between weight loss and gut microbiota composition in overweight adolescents

The aim of this study was to determine the influence of an obesity treatment program on the gut microbiota and body weight of overweight adolescents. Thirty-six adolescents (13-15 years), classified as overweight according to the International Obesity Task Force BMI criteria, were submitted to a calorie-restricted diet (10-40%) and increased physical activity (15-23 kcal/kg body weight/week) program over 10 weeks. Gut bacterial groups were analyzed by quantitative real-time PCR before and after the intervention. A group of subjects (n=23) experienced >4.0 kg weight loss and showed significant BMI (P=0.030) and BMI z-score (P=0.035) reductions after the intervention, while the other group (n=13) showed <2.0 kg weight loss. No significant differences in dietary intake were found between both groups. In the whole adolescent population, the intervention led to increased Bacteroides fragilis group (P=0.001) and Lactobacillus group (P=0.030) counts, and to decreased Clostridium coccoides group (P=0.028), Bifidobacterium longum (P=0.031), and Bifidobacterium adolescentis (P=0.044) counts. In the high weight-loss group, B. fragilis group and Lactobacillus group counts also increased (P=0.001 and P=0.007, respectively), whereas C. coccoides group and B. longum counts decreased (P=0.001 and P=0.044, respectively) after the intervention. Total bacteria, B. fragilis group and Clostridium leptum group, and Bifidobacterium catenulatum group counts were significantly higher (P<0.001-0.036) while levels of C. coccoides group, Lactobacillus group, Bifidobacterium, Bifidobacterium breve, and Bifidobacterium bifidum were significantly lower (P<0.001-0.008) in the high weight-loss group than in the low weight-loss group before and after the intervention. These findings indicate that calorie restriction and physical activity have an impact on gut microbiota composition related to body weight loss, which also seem to be influenced by the individual's microbiota.

Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study

OBJECTIVE

To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.

DESIGN

Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.

RESULTS

The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.

CONCLUSION

The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.

[Validity of four questionnaires to assess physical activity in Spanish adolescents]

OBJECTIVES

The physical activity (PA) levels of Spanish adolescents must be determined to assess how the lack of PA may affect the increasing prevalence of obesity. Thus, to assess PA in this age range valid measurement instruments are essential. The aim of this study was to evaluate the validity of four easily applied questionnaires (the enKid and FITNESSGRAM questions, the Patient-Centered Assessment and Counselling [PACE] questionnaire, and an activity rating) to assess PA in Spanish adolescents by using an accelerometer as the criterion instrument.

METHODS

A total of 232 adolescents (113 girls) completed the questionnaires and wore an ActiGraph accelerometer for 7 consecutive days. Spearman's correlation coefficient (rho) was used to compare the questionnaires and total PA, moderate PA, vigorous PA and moderate-to-vigorous PA (MVPA) assessed by the accelerometer.

RESULTS

All the questionnaires showed moderate correlations when compared against total PA (rho=0.36-0.43) and MVPA (rho=0.34-0.46) obtained by the accelerometer in the total sample. Higher correlations were found when comparing the questionnaires against vigorous PA (rho=0.42-0.51) than against moderate PA (rho=0.15-0.17). The FITNESSGRAM question and the PACE questionnaire obtained weak correlations in girls and the enKid question and activity rating were moderately correlated for boys and girls.

CONCLUSIONS

The four questionnaires evaluated showed acceptable validity in the assessment of PA in the Spanish adolescent population.