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

Correlations of Anthropometric Measurements With Body Fat Percentage, Fat Mass, and Fat Mass Index in School-Age Children

BACKGROUND

Childhood obesity is a growing public health issue globally, including in India. Anthropometric measures such as body mass index (BMI), waist circumference, and skinfold thickness are commonly used to estimate body fat percentage (BF%), but their correlations with fat mass (FM) and fat mass index (FMI) are less emphasized. This study aimed to explore the relationships between anthropometric measurements and body fat indicators (BF%, FM, and FMI) in school-age children and obtain prediction equations for FM and FMI.

METHODS

This observational cross-sectional study included 250 children (125 boys, 125 girls) aged six to 15 years. Anthropometric measures (BMI, waist circumference, skinfold thickness, etc.) and body composition (via bioelectrical impedance analysis) were collected. Pearson's correlation and multiple regression analyses were used to assess the relationships between anthropometric measurements and body fat indicators and to develop prediction models.

RESULTS

BMI, waist circumference, and triceps skinfold thickness showed strong correlations with FM (r = 0.74, r = 0.73, r = 0.61, respectively) and FMI (Pearson's correlation coefficient (r) = 0.76, r = 0.64, r = 0.57, respectively), while the waist-to-height ratio (r = 0.08) and the arm-to-height ratio (r = 0.12) were poorly correlated with BF%. Our prediction equations for FM and FMI provided better predictive values (R² = 0.75 and 0.69, respectively) than BF% (coefficient of determination (R2) = 0.35).

CONCLUSION

FM and FMI showed stronger correlations with anthropometric measurements than BF%. The waist-to-height ratio and the arm-to-height ratio had small correlations with all three body fat indicators. The prediction equation for FM and FMI outperformed the one for BF%, underscoring their potential utility in assessing adiposity in school-age children.

Waist-circumference-to-height-ratio had better longitudinal agreement with DEXA-measured fat mass than BMI in 7237 children

BACKGROUND

The absolute agreement of surrogate measures of adiposity with dual-energy X-ray absorptiometry (DEXA)-measured body composition was examined.

METHODS

Over a 15-year follow-up, 7237 (3667 females) nine-year-old children from the Avon Longitudinal Study of Parents and Children (ALSPAC) UK birth cohort were included. Total fat mass (FM) and trunk FM were serially measured with DEXA at ages 9, 11, 15, 17, and 24 years. BMI and waist circumference-to-height ratio (WHtR) were computed. Pearson's correlations, intraclass correlations (ICC), and area under curve (AUC) analyses were conducted.

RESULTS

Over 15 years, BMI, total FM, and trunk FM, increased but WHtR was relatively stable. WHtR provided a better longitudinal absolute agreement [males ICC 0.84 (95% CI 0.84-0.85); females 0.81 (0.80-0.82)] than BMI [(males (0.65 (0.64-0.66); females 0.72 (0.71-0.73)] with total FM as well as trunk FM from ages 9-24 years. WHtR cut-point for predicting excess total FM (75th-95th percentile) was 0.50-0.53 in males [AUC 0.86-0.94, sensitivity 0.51-0.79 and specificity 0.93-0.95]. WHtR cut-point for predicting excess total FM (75th-95th percentile) was 0.52-0.54 in females [AUC 0.83-0.95, sensitivity 0.38-0.68 and specificity 0.92-0.95]. Results were similar with trunk FM.

CONCLUSION

WHtR is an inexpensive alternative to BMI for predicting FM in pediatrics.

IMPACT

Waist circumference-to-height ratio (WHtR) is a better adiposity surrogate measure than body mass index (BMI) in predicting fat mass and discriminating lean mass from childhood through young adulthood. BMI has been used as an inexpensive surrogate measure of adiposity in children for several decades. However, emerging findings suggest that BMI fails to discriminate between fat mass adiposity and lean mass. This is the first-ever longitudinal study in over 7000 children followed up for 15 years that identified WHtR as an inexpensive accurate measure that discriminates fat mass from lean mass that could replace BMI measure of obesity in pediatrics.

Assessing the Dietary Practices and Anthropometric Outcomes of Students Consuming Mid-day Meals Versus Home-Cooked Meals

INTRODUCTION

 Early childhood and adolescence are prime years that people spend in school. These formative years give the school ample opportunities to impart certain aspects of lifestyle and healthcare to the student, in addition to academics. School health programs are vital in providing comprehensive education and healthcare services. The objectives of the study are to enlist the socio-demographic factors affecting the nutritional level between students who enrolled for the mid-day meal scheme and those who did not.

METHODOLOGY

 This is a cross-sectional questionnaire-based study, which was carried out between children who enrolled in the mid-day meal program and home-cooked meals for students from 3rd to 12th grade in Faridabad. The study was conducted by the Department of Public Health Dentistry, Faridabad, from January to June 2024.

RESULT

 It was determined that 162 (53.6%) males and 222 (74.9%) females were obese. 332 (55.3%) believed that social media had an impact on their dietary decisions, while 268 (44.7%) disagreed. When asked to rate how many healthy food alternatives were available at their school, 53 (8.8%) of them said it was great, 194 (32.3%) said it was good, 196 (32.7%) said it was fair, and 157 (26.2%) said it was poor. 236 (78.7%) parents of the mid-day meal group never had dietary supplemental education, which is why children have indigent nutritional status. The mean waist-to-hip ratio (WHR) was calculated as 0.92 ± 0.43 and 0.88 ± 0.69 with significant values of 0.00 (p≤0.05) in the home-cooked and mid-day meal-consuming groups respectively.

CONCLUSION

 Students consuming home-cooked meals showed a better WHR for age than those consuming mid-day meals. Children of parents with high education levels have good nutritional status and are healthier as compared to children with parents who have low education levels. Thus, there is a dire need to include school health programs to provide healthy and nutritious food to children, in need.

BODYFAT: a new calculator to determine the risk of being overweight validated in Spanish children between 11 and 17 years of age

The assessment of body fat of children in primary care requires consideration of the dynamic changes in height, weight, lean mass, and fat mass during childhood growth. To achieve this, we aim to develop a predictive equation based on anthropometric values, with optimal diagnostic utility. This is a cross-sectional observational study, involving schoolgoers aged 11-17 years in the Vigo metropolitan area. Out of 10,747 individuals, 577 were randomly recruited.

VARIABLES

age, sex, ethnicity/country of origin, weight, height, 8 skinfolds, 3 diameters, 7 perimeters, and 85% percentile of body fat mass as the gold standard. Generalized additive regression was selected by cross-validation and compared using receiver operating characteristic curves (ROC curves). Sensitivity, specificity, positive and negative predictive values, true positive and true negative values, false positive and false negative values, accuracy, and positive and negative likelihood ratios were calculated. Two models were identified. The optimal model includes sex, weight, height, leg perimeter, and arm perimeter, with sensitivity of 0.93 (0.83-1.00), specificity of 0.91 (0.83-0.96), accuracy of 0.91 (0.84-0.96), and area under the curve (AUC) of 0.957 (0.928-0.986). The second model includes sex, age, and body mass index, with sensitivity of 0.93 (0.81-1.00), specificity of 0.90 (0.80-0.97), accuracy of 0.90 (0.82-0.96), and an AUC of 0.944 (0.903-0.984).

CONCLUSION

Two predictive models, with the 85th percentile of fat mass as the gold standard, built with basic anthropometric measures, show very high diagnostic utility parameters. Their calculation is facilitated by a complementary online calculator.

WHAT IS KNOWN

• In routine clinical practice, mainly in primary care, BMI is used to determine overweight and obesity. This index has its weaknesses in the assessment of children.

WHAT IS NEW

• We provide a calculator whose validated algorithm, through the determination of fat mass by impedanciometry, makes it possible to determine the risk of overweight and obesity in the community setting, through anthropometric measurements, providing a new practical, accessible and reliable model that improves the classification of overweight and obesity in children with respect to that obtained by determining BMI.

Waist-height ratio and body mass index as indicators of obesity and cardiometabolic risk in Korean children and adolescents

PURPOSE

We assessed the clinical relevance of waist-height ratio (WHtR) as an indicator of cardiometabolic risk and body fat mass measured by dual-energy x-ray absorptiometry (DXA) among Korean children and adolescents.

METHODS

Data from 1,661 children and adolescents aged 10-18 years who participated in the Korea National Health and Nutrition Examination Survey were analyzed. Unadjusted Pearson correlation, age- and sex-adjusted Pearson correlation, and multiple linear regression analyses were performed to investigate the relationships between WHtR standard deviation score (SDS) and cardiometabolic risk factors, as well as DXA-assessed parameters.

RESULTS

WHtR SDS was correlated with cardiometabolic risk factors, including systolic blood pressure, glucose, total cholesterol, high-density lipoprotein cholesterol, triglyceride, and low-density lipoprotein cholesterol, as well as DXA-assessed parameters such as lean mass SDS, fat mass SDS, and fat mass percentage SDS in both whole body and trunk using an adjusted Pearson correlation analyses among all participants (p<0.001). WHtR SDS was strongly correlated with whole-body fat mass and trunk fat mass (r=0.792, p<0.001 and r=0.801, p<0.001, respectively) whereas WHtR SDS had a low correlation coefficient with whole-body lean mass and trunk lean mass SDS (r=0.512, p<0.001 and r=0.487, p<0.001, respectively). In multiple linear regression analyses, WHtR SDS was significantly associated with whole-body and trunk fat mass after adjustment for confounders.

CONCLUSION

Cardiometabolic risk factors and body fat mass assessed by DXA in Korean children and adolescents were highly correlated with WHtR. Additionally, WHtR has an advantage in distinguishing fat-free mass. WHtR can be a useful and convenient clinical indicator of cardiometabolic risk factors.

EDC mixtures during pregnancy and body fat at 7 years of age in a Swedish cohort, the SELMA study

BACKGROUND

Some endocrine disrupting chemicals (EDC), are "obesogens" and have been associated with overweight and obesity in children. Daily exposure to different classes of EDCs demands for research with mixtures approach.

OBJECTIVES

This study evaluates the association, considering sex-specific effects, between prenatal exposure to EDC mixture and children's body fat at seven years of age.

METHODS

A total of 26 EDCs were assessed in prenatal urine and serum samples from first trimester in pregnancy from 737 mother-child pairs participating in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study. An indicator for children's "overall body fat" was calculated, using principal component analysis (PCA), based on BMI, percent body fat, waist, and skinfolds measured at seven years of age. Weighted quantile sum (WQS) regression was used to assess associations between EDC mixture and children's body fat.

RESULTS

Principal component (PC1) represented 83.6 % of the variance, suitable as indicator for children's "overall body fat", with positive loadings of 0.40-0.42 for each body fat measure. A significant interaction term, WQS*sex, confirmed associations in the opposite direction for boys and girls. Higher prenatal exposure to EDC mixture was borderline significant with more "overall body fat" for boys (Mean β = 0.20; 95 % CI: -0.13, 0.53) and less for girls (Mean β = -0.23; 95 % CI: -0.58, 0.13). Also, higher prenatal exposure to EDC mixture was borderline significant with more percent body fat (standardized score) for boys (Mean β = 0.09; 95 % CI: -0.04, 0.21) and less for girls (Mean β = -0.10 (-0.26, 0.05). The chemicals of concern included bisphenols, phthalates, PFAS, PAH, and pesticides with different patterns for boys and girls.

DISCUSSION

Borderline significant associations were found between prenatal exposure to a mixture of EDCs and children's body fat. The associations in opposite directions suggests that prenatal exposure to EDCs may present sex-specific effects on children's body fat.

Effect of COVID-19 Pandemic Lockdowns on Body Mass Index of Primary School Children from Different Socioeconomic Backgrounds

BACKGROUND

Childhood obesity is associated with various health outcomes. Restrictive measures to contain the spread of the Coronavirus Disease 2019 (COVID-19) pandemic, like lockdowns and school closures, affected children's daily structure, physical activity, dietary habits, and sleep quality, possibly exacerbating risk factors for childhood obesity and higher body mass index (BMI) in children. Poor socioeconomic conditions may have led to relatively higher risk for elevated BMI levels following pandemic measures. In this study, the impact of measures related to the COVID-19 pandemic on the BMI of third graders was investigated regarding children's socioeconomic background (SEB).

METHODS

Data from 41,728 children (8.84 ± 0.56 years, 20,431 female) were collected in the context of a cohort study. Children were tested either before the pandemic (preCOVID: Sept2017-March2020, n = 26,314), or following the first (postLDI: Aug2020-Dec2020, n = 6657) or second lockdown in Germany (postLDII: Aug2021-Jan2022, n = 8757). SEB was based on the official school type classification of the state of Berlin. Outcome was BMI standard deviation scores (SDS).

RESULTS

Significant effects of Time and SEB revealed elevated BMIs in postLDI (M = 0.23, p = 0.011) and postLDII (M = 0.22, p = 0.011) compared to preCOVID (M = 0.17) cohorts and higher BMIs for children with lower SEB (b = - 0.13, p < 0.001). A significant Time × SEB interaction indicated that the effect of SEB on children's BMI increased in response to lockdowns, especially in postLDII (b = - 0.05, p = 0.006). Results suggest that the COVID-19-related measures lead to increased BMI in children, and that children of lower SEB were at particular risk for higher BMIs following lockdowns.

CONCLUSIONS

These findings highlight the dependency of children's BMI on societal circumstances. Over the course of two lockdowns in Germany, children have experienced BMI increments, particularly in low socioeconomic areas. Authorities are called into action to counteract increasing rates of childhood weight by promoting physical activity of children and establishing related post-pandemic offers.

Maternal nutrition during mid-pregnancy and children's body composition at 7 years of age in the SELMA study

Optimal nutrition during pregnancy is vital for both maternal and child health. Our objective was to explore if prenatal diet is associated with children's height and body fat. Nutrient intake was assessed through a FFQ from 808 pregnant women and summarised to a nutrition index, 'My Nutrition Index' (MNI). The association with children's height and body fat (bioimpedance) was assessed with linear regression models. Secondary analysis was performed with BMI, trunk fat and skinfolds. Overall, higher MNI score was associated with greater height (β = 0·47; (95 % CI 0·00, 0·94), among both sexes. Among boys, higher MNI was associated with 0·15 higher BMI z-scores, 0·12 body fat z-scores, 0·11 trunk fat z-scores, and larger triceps, and triceps + subscapular skinfolds (β = 0·05 and β = 0·06; on the log2 scale) (P-value < 0·05). Among girls, the opposite associations were found with 0·12 lower trunk fat z-scores, and smaller subscapular and suprailiac skinfolds (β = -0·07 and β = -0·10; on the log2 scale) (P-value < 0·05). For skinfold measures, this would represent a ± 1·0 millimetres difference. Unexpectedly, a prenatal diet in line with recommended nutrient intake was associated with higher measures of body fat for boys and opposite to girls at a pre-pubertal stage of development.

Adiposity is not associated with caries among youth in the United States

BACKGROUND

Body mass index has been traditionally used to determine the nutritional status of children in studies on obesity and caries. Imaging methods provide a superior assessment of body fat. This study investigated the relationship between measures of adiposity and caries in permanent teeth in children and adolescents.

METHODS

The analysis included 5,694 participants in the National Health and Nutrition Examination Survey from 2011 through 2018, aged 8 through 19 years. The body fat percentage (BF%) and fat mass index (FMI) were determined from whole-body dual-energy x-ray absorptiometry scans. Excess adiposity was defined as a sex- and age-specific value at or above the 75th percentile according to the US reference standards for BF% or FMI. Caries was measured with the decayed teeth and decayed, missing, and filled teeth indexes; prevalence of untreated dentin caries; and lifetime caries prevalence. The associations between adiposity and caries were tested in confounding variables-adjusted regression models.

RESULTS

The FMI score was associated with the decayed, missing, and filled teeth score (rate ratio, 1.03; 95% CI, 1.01 to 1.05) and lifetime caries prevalence (odds ratio, 1.06; 95% CI, 1.03 to 1.08), but the associations attenuated after adjustment for confounding variables. Neither the BF% score nor the presence of excess adiposity, defined according to the BF% or FMI reference standards, were associated with caries.

CONCLUSION

The authors found no association between measures of adiposity and caries among US children and adolescents.

PRACTICAL IMPLICATIONS

Caries is a multifactorial disease, and any observed association between obesity and caries is most likely due to the shared determinants and risk factors of both conditions.

Air Displacement Plethysmography is an Accurate and Feasible Noninvasive Measure of Fat-Free Mass in Children With Intestinal Failure

BACKGROUND

The nutritional status of children with intestinal failure (IF) can be difficult to determine using body weight and currently available anthropometric techniques. Air displacement plethysmography (ADP) is a noninvasive measure of whole-body composition that measures body mass and volume, with a calculation of percent body fat (%BF) and fat-free mass (FFM) that may be useful during the provision of specialized nutrition.

OBJECTIVES

To evaluate the validity and feasibility of measuring body composition in children with IF using ADP compared with deuterium dilution (DD), as well as secondarily with other measures of body composition, namely bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), and four-site skinfold anthropometry.

METHODS

We conducted a prospective cohort study of 18 children recruited through the Center for Advanced Intestinal Rehabilitation at Boston Children's Hospital. Patients 2-17 years of age with IF dependent on parenteral nutrition (PN) for more than 90 days were included. Spearman rank correlation and Bland-Altman limits of agreement (LOA) analysis were used to compare ADP to 4 alternative measures of body composition.

RESULTS

Eighteen children with IF, median age 7.1 [interquartile range (IQR) 5.4-9.3] years, 9 female (50%), and median residual bowel length 31 (IQR 22-85) cm were enrolled. Median PN energy intake was 46 (IQR 39-49) kcal/kg/day. Incomplete bladder emptying lead to invalid measures of DD in 4 subjects. Spearman correlation coefficients for %BF were low to moderate between ADP and DD ( r = 0.29), DXA ( r = 0.62), BIA ( r = 0.50), and skinfold ( r = 0.40). Correlations for FFM were high between ADP and these other measures (range 0.95-0.98). Comparing ADP with DD and skinfold measures, Bland-Altman analysis showed small mean bias (-1.9 and +1.5 kg) and acceptable 95% LOA ranges (10.7 and 22.9 kg), respectively, with larger bias (-10.7 and -7.7 kg) and LOA ranges (38.7 and 45.2 kg) compared to DXA and BIA. %BF by ADP and skinfold thickness were moderately correlated ( r = 0.43) with low bias (-0.2%) but very wide LOA (25.7%).

CONCLUSIONS

Body composition via ADP is feasible and valid in children with IF as a measure of FFM but appears less suitable for the measurement of %BF. The technique holds promise as a noninvasive measure of body composition to assess the efficacy of nutritional, medical, and surgical interventions.

Different criteria for body mass index classification for excess weight screening in children aged six to ten years

OBJECTIVE

To evaluate the agreement between body mass index (BMI) parameters applied to children aged six to ten years in the city of Montes Claros (MG), Brazil with national and international criteria, also calculating their sensitivity and specificity regarding excess weight screening.

METHODS

A sample comprising 4151 children aged six to ten years was assessed, with height and body mass determined for BMI calculation. The obtained values were classified according to cutoff points established by the World Health Organization (WHO), International Obesity Task Force (IOTF), Centers for Disease Control and Prevention (CDC), Conde & Monteiro, and a recent local proposal. The agreement index between the mentioned criteria was calculated and thereafter the sensitivity and specificity.

RESULTS

The local proposal was proven to be highly consistent in most combinations, especially concerning the excess weight criteria of the World Health Organization (WHO) (k=0.895). Regarding excess weight, the local proposal presented sensitivity and specificity values of 0.8680 and 0.9956, respectively, indicating high BMI discrimination power.

CONCLUSIONS

The locally applied BMI parameters for children aged six to ten years represent a valid, highly viable and practical proposal for excess weight screening in this population group, improving professional decision-making in their follow-up.

Changes in general and abdominal obesity in children at 4, 6 and 9 years of age and their association with other cardiometabolic risk factors

Temporary changes in childhood obesity and their association with cardiometabolic risk factors have been receiving increased attention. The objective of this study was to evaluate changes in general (GO) and abdominal (AO) obesity in children from 4 to 9 years of age and their associations with cardiometabolic risk factors at 9 years of age. This study includes 1344 children from the Longitudinal Childhood Obesity Study (ELOIN). Physical examinations performed at 4, 6 and 9 years of age and a blood sample was only taken at 9 years of age. Changes in obesity from 4 to 9 years of age were estimated using Body Mass Index and waist circumference. Participants were classified into four groups according to GO and AO: (1) stable without obesity (no obesity at all three measurements); (2) remitting obesity at 9 years (obesity at 4 and/or 6 years but not at 9 years); (3) incident or recurrent obesity at 9 years (obesity only at 9 years, at 4 and 9 years or at 6 and 9 years); and (4) stable or persistent with obesity (obesity at 4, 6 and 9 years). Dyslipidemia and dysglycemia were defined by the presence of at least one altered parameter of the lipid or glycemic profile. Odds ratios (OR) were estimated using logistic regression. Compared with children without GO at all ages, those with persistent GO had an OR of 3.66 (95% CI: 2.06-6.51) for dyslipidemia, 10.61 (95% CI: 5.69-19.79) for dysglycemia and 8.35 (95% CI: 4.55-15.30) for high blood pressure. The associations were fairly similar in the case of AO, with ORs of 3.52 (95% CI: 1.96-6.34), 17.15 (95% CI: 9.09-32.34) and 8.22 (95% CI: 4.46-15.15), respectively, when comparing persistent versus stable without AO. Children with incident obesity at 9 years presented a moderate cardiometabolic risk that was nevertheless higher compared to those stable without obesity, whereas those with remitting obesity did not show any significant associations.

CONCLUSION

Incident, and especially, persistent obesity, is associated with an increased cardiometabolic risk. The very early prevention of obesity, with a focus on nutrition, physical activity and sedentary behaviour, as well as tracking growth from birth to age 5, should be a priority to prevent the burden of cardiometabolic disease with consequences for adulthood.

WHAT IS KNOWN

• General and abdominal obesity has been shown to be associated with other cardiometabolic risk factors such as dyslipidemia, insulin resistance and hypertension. • Temporary changes in obesity and their associations with cardiometabolic risk factors have not been sufficiently explored in childhood.

WHAT IS NEW

• Children with incident, and especially persistent, general and/or abdominal obesity, had an increased risk of dyslipidemia, dysglycemia and high blood pressure. •Remitting obesity was not associated with an increased cardiometabolic risk.

Body-Fat-Percentile Curves for Thai Children and Adolescents

This study aimed to generate sex-specific percentile curves for the percentage of body fat (PBF) in Thai children using a bioelectrical impedance analysis (BIA). The secondary objective of this study was to determine the association between body fat and other anthropometric measurements. A cross-sectional study was conducted on 3455 Thai school children aged 6-18 years. The body-fat contents were measured using BIA. Smoothed percentile curves of PBF were derived using a scatter plot with a smooth curve fitted by the Loess method. The correlations between the body fat and the anthropometric measurements were assessed using the Spearman's rank correlation. The 50th and lower body-fat-percentile curves of the boys slowly increased until age 12, after which they slightly decreased until age 15 and then slightly increased until age 18. In the higher boys' percentiles, the body fat sharply increased until age 11 and then decreased until age 18. In the girls, the PBF percentiles increased steadily from 6 to 18 years. The body-mass index was strongly correlated with PBF and fat mass in both sexes. The waist-to-height ratios showed strong correlations with PBF and fat mass in the boys but were moderate in the girls. The use of PBF percentile curves can be an additional metric for the evaluation of obesity in Thai children.

A height-weight formula to measure body fat in childhood obesity

Background

The assessment of body composition is central in diagnosis and treatment of paediatric obesity, but a criterion method is not feasible in clinical practice. Even the use of bioelectrical impedance analysis (BIA) is limited in children. Body mass index (BMI) Z-score is frequently used as a proxy index of body composition, but it does not discriminate between fat mass and fat-free mass. We aimed to assess the extent to which fat mass and percentage of body fat estimated by a height-weight equation agreed with a BIA equation in youths with obesity from South Italy. Furthermore, we investigated the correlation between BMI Z-score and fat mass or percentage of body mass estimated by these two models.

Methods

One-hundred-seventy-four youths with obesity (52.3% males, mean age 10.8 ± 1.9) were enrolled in this cross-sectional study. Fat mass and percentage of body fat were calculated according to a height-weight based prediction model and to a BIA prediction model.

Results

According to Bland–Altman statistics, mean differences were relatively small for both fat mass (+ 0.65 kg) and percentage of body fat (+ 1.27%) with an overestimation at lower mean values; the majority of values fell within the limits of agreement. BMI Z-score was significantly associated with both fat mass and percentage of body fat, regardless of the method, but the strength of correlation was higher when the height-weight equation was considered (r = 0.82; p < 0.001).

Conclusions

This formula may serve as surrogate for body fat estimation when instrumental tools are not available. Dealing with changes of body fat instead of BMI Z-score may help children and parents to focus on diet for health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01285-8.

Prenatal and childhood exposure to chlordecone and adiposity of seven-year-old children in the Timoun mother-child cohort study in Guadeloupe (French West Indies)

BACKGROUND

Exposure to persistent environmental organic pollutants may contribute to the development of obesity among children. Chlordecone is a persistent organochlorine insecticide with estrogenic properties that was used in the French West Indies (1973-1993) and is still present in the soil and the water and food consumed by the local population. We studied the association between prenatal and childhood exposure to chlordecone and the adiposity of prepubertal children.

METHODS

Within the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies), 575 children had a medical examination at seven years of age, including adiposity measurements. A Structural Equation Modeling approach was used to create a global adiposity score from four adiposity indicators: the BMI z-score, percentage of fat mass, sum of the tricipital and subscapular skinfold thickness, and waist-to-height ratio. Chlordecone concentrations were measured in cord blood at birth and in the children's blood at seven years of age. Models were adjusted for prenatal and postnatal covariates. Sensitivity analyses accounted for co-exposure to PCB-153 and pp'-DDE. Mediation analyses, including intermediate birth outcomes, were conducted.

RESULTS

Prenatal chlordecone exposure tended to be associated with increased adiposity at seven years of age, particularly in boys. However, statistical significance was only reached in the third quartile of exposure and neither linear nor non-linear trends could be formally identified. Consideration of preterm birth or birth weight in mediation analyses did not modify the results, as adjustment for PCB-153 and pp'-DDE co-exposures.

CONCLUSION

Globally, we found little evidence of an association between chlordecone exposure during the critical in utero or childhood periods of development and altered body-weight homeostasis in childhood. Nevertheless, some associations we observed at seven years of age, although non-significant, were consistent with those observed at earlier ages and would be worth investing during further follow-ups of children of the Timoun Mother-Child Cohort Study when they reach puberty.

Changes in body composition and cardiometabolic risk factors in relation to the reduction in body mass index in adolescents with obesity

INTRODUCTION

there are controversial data in relation to the reduction in body mass index standard deviation score (BMI-SDS) needed to improve adiposity in the pediatric population with obesity. The aim of this work was to determine the minimum variation in BMI-SDS required to improve the values of adiposity markers and cardiometabolic risk factors in growing adolescents with obesity.

METHODS

a longitudinal study consisting of clinical evaluation (waist circumference, waist-to-height ratio, fat mass index, and blood pressure) and blood testing (insulin resistance and lipid profile) was conducted in 350 adolescents with obesity (152 boys and 198 girls) aged 10.2-14.3 years who went through a combined intervention (12 months).

RESULTS

a decrease in SDS-BMI ≤ 0.5 was not associated with any significant improvement in the clinical features and blood testing recorded. A decrease in BMI-SDS > 0.5, and especially if > 1.0, was linked to a significant improvement in adiposity markers. A decrease in BMI-SDS > 0.5 was associated with a significant improvement in insulin resistance, and a decrease in BMI-SDS > 1.0 was associated with a significant decrease in the percentage of patients who showed high values of systolic blood pressure, HOMA-IR, and lipid profile Conclusions: improvement in body composition, insulin resistance, and lipid profile can be observed with reductions in BMI-SDS ≥ 0.5 in obese adolescents, while extended benefits are obtained by losing at least 1.0 BMI-SDS.

Revisiting trajectories of BMI in youth: An in-depth analysis of differences between BMI and other adiposity measures

OBJECTIVE

Body mass index (BMI) is used to identify trajectories of adiposity in youth, but it does not distinguish fat- from fat-free-mass. There are other inexpensive measures of adiposity which might better capture fat-mass in youth The objective of this study is to examine differences between sex-specific trajectories of BMI and other adiposity indicators (subscapular and triceps skinfold thickness, waist circumference, waist-to-height ratio) which may better capture fat-mass in youth.

METHODS

Data come from four cycles of a longitudinal cohort of 1293 students in Montréal, Canada at ages 12, 15, 17 and 24. Group-based trajectory models identified sex-specific adiposity trajectories among participants with data in ≥3 cycles (n = 417 males; n = 445 females).

RESULTS

There were six trajectory groups in males and females for all five indicators, except for waist circumference (seven) in both sexes and triceps skinfold thickness (four) and waist-to-height ratio (five) in females. Most trajectories indicated linear increases; only the skinfold thickness indicators identified a decreasing trajectory. While all indicators identified a trajectory with high levels of adiposity, they differed in the number and relative size of trajectories pertaining to individuals in lower half of the adiposity distribution.

CONCLUSION

BMI is a satisfactory indicator of adiposity in youth if the aim of the trajectory analysis is to identify youth with excess adiposity, a known risk factor for cardiometabolic outcomes in adulthood.

Health-Related Physical Fitness and Activity in Homeschool: A Systematic Review With Implications for Return to Public School

BACKGROUND

The purpose of this systematic review is to summarize what is known about health-related physical fitness (cardiovascular endurance, muscular strength and endurance, flexibility, and body composition) and physical activity among homeschool youth. Findings from this study have implications for all American youth as they return to public school from mandated schooling at home during the COVID-19 pandemic.

METHODS

Database engines identified over 22,000 articles with 82 abstracts screened for further review. Of these, 18 full-text articles were additionally screened with 10 cross-sectional articles included in the final review. Articles were condensed into a standard review template and findings were summarized by topic.

RESULTS

Cardiovascular endurance findings were inconsistent. Abdominal, but not upper body, muscular strength and endurance were significantly lower in homeschool students. There were no reports on flexibility. Body composition was generally healthy in homeschool students and no differences in physical activity were seen.

CONCLUSIONS

Research on health-related physical fitness in homeschool youth is limited and descriptive. Further testing and potential remediation may be needed for cardiovascular endurance, muscular strength and endurance, and flexibility in homeschool youth and their public school counterparts as they return to campus. However, existing literature supports healthy body composition and physical activity in this population.

Feasibility of Using Bioelectrical Impedance Analysis for Assessing Youth Weight and Health Status: Preliminary Findings

Background. This study assessed the accuracy of bioimpedance analysis (BIA) for measuring body composition and resting metabolic rate (RMR) in fasted and non-fasted state and the prospect of using phase angle (PA) to indicate cellular health in youth. Methods. BIA body composition, RMR, and hydration measures were compared to dual-energy x-ray absorptiometry (DXA), MedGem metabolic analyzer, and urine specific gravity, respectively, at baseline in a fasted state using one-way ANOVAs. Repeated BIAs at 0, 30, 60, 90, and 120 min post-prandial were compared to baseline using repeated-measures ANOVA. Correlations were used to assess the relationship among PA and health (blood lipids and glucose, resting BP) and fitness (grip strength and a 3 min step test) measures. Results. BIA scans (N = 58; 11.4 ± 2.9 y) measured lower body fat % (BF%) in healthy weight youth (BMI < 85th percentile; 16.4 ± 1.1 vs. 25.1 ± 1.0%) and lower visceral adipose tissue (VAT) in males (44.5 ± 2.9 vs. 34.1 ± 6.0 cm2) than DXA and higher RMR in all youth (1244 ± 41 vs. 1104 ± 39 kcals/day), healthy weight (1231 ± 48 vs. 1049 ± 44 kcals/day), and teens (1541 ± 62 vs. 1234 ± 72 kcals/day) than MedGem. Compared to baseline, immediate post-prandial values were significantly higher for BF% (21.4 ± 1.4 vs. 22.0 ± 1.4%) and VAT (45.4 ± 6.1 vs. 46.2 ± 6.2 cm2). PA was significantly correlated with BF% (r = -0.33; p = 0.01), fat-free mass (r = 0.59; p < 0.001), grip strength (r = 0.56; p < 0.001). Conclusions. While more data are needed to confirm these preliminary findings, the results suggest caution is necessary in using BIA to assess aspects of youth health and weight status, especially in males, healthy weight, and teens. However, these preliminary findings do indicate that phase angle maybe be a valuable, non-invasive tool for identifying youth who are heading towards obesity and/or obesity-related health consequences.

Obesity and Metabolic Care of Children of South Asian Ethnicity in Western Society

South Asians constitute one-fourth of the world’s population and are distributed significantly in western countries. With exponentially growing numbers, childhood obesity is of global concern. Children of South Asian ancestry have a higher likelihood of developing obesity and associated metabolic risks. The validity of commonly used measures for quantifying adiposity and its impact on metabolic outcomes differ by race and ethnicity. In this review we aim to discuss the validity of body mass index (BMI) and other tools in screening for adiposity in South Asian children. We also discuss the prevalence of overweight and obesity amongst South Asian children in western countries and the differences in body fat percentage, adiposity distribution, and metabolic risks specific to these children compared to Caucasian children. South Asian children have a characteristic phenotype: lower lean mass and higher body fat percentage favoring central fat accumulation. Hence, BMI is a less reliable predictor of metabolic status in these children than it is for Caucasian children. Furthermore, the relatively lower birth weight and rapid growth acceleration in early childhood of South Asian children increase the risk of their developing cardiometabolic disorders at a younger age than that of Caucasians. We emphasize the need to use modified tools for assessment of adiposity, which take into consideration the ethnic differences and provide early and appropriate intervention to prevent obesity and its complications.

Subcutaneous Adipose Tissue Measured by B-Mode Ultrasound to Assess and Monitor Obesity and Cardio-Metabolic Risk in Children and Adolescents

Simple Summary

The prevention and treatment of childhood and adolescent overweight and obesity raises the need for accurate body fat assessment. Precise methods are at high technical expense, require exposure to ionizing radiation and are limited to institutional investigations, while common body indicators fail to identify excess body fat. Subcutaneous adipose tissue measured by ultrasound is an alternative approach, which was evaluated in relation to commonly applied body indicators to assess cardio–metabolic risk and its applicability in the field. Subcutaneous adipose tissue measured by ultrasound indicated a clear advantage over commonly applied body indicators and implies that severe body fat assessment errors are to be expected when BMI is used as a measure for body fatness in children. Children or adolescents with identical BMIs may have large differences (>200%) in their amount of subcutaneous adipose tissue. Ultrasound provides an easily applicable, reliable and safe method for accurate assessment of obesity and monitoring treatment responses in children and adolescents at cardio–metabolic risk.

Abstract

Monitoring of children at heightened risk of cardio–metabolic diseases raises the need for accurate assessment of obesity. A standardized approach for measuring subcutaneous adipose tissue (SAT) by bright-mode ultrasound was evaluated in relation to body indices and anthropometry in a cross-sectional sample of 76 South African children (7–10 years) and 86 adolescents (13–17 years) to assess cardio–metabolic risk. SAT was higher in girls as compared to boys (children: 50.0 ± 21.7 mm > 34.42 ± 15.8 mm, adolescents: 140.9 ± 59.4 mm > 79.5 ± 75.6 mm, p < 0.001) and up to four times higher in adolescents than in children. In children, measures of relative body weight showed only a poor correlation to SAT (BMI: r = 0.607, p < 0.001), while in adolescents, BMI correlated high with SAT (r = 0.906, p < 0.001) based on high rates of overweight and obesity (41.8%). Children with identical BMIs may have large differences (>2–3-fold) in their amount of SAT. The moderate association to systolic (r = 0.534, r = 0.550, p < 0.001) and diastolic blood pressure (r = 0.402, r = 0.262, p < 0.001) further substantiates that SAT measured by ultrasound provides an accurate, safe and easy applicable approach for monitoring in children and adolescents at cardio–metabolic risk.

Gonadotropin releasing hormone analogue therapy in girls with idiopathic precocious puberty/early-fast puberty: dynamics in adiposity indices, eating habits and quality of life

BACKGROUND

The impact of gonadotropin-releasing-hormone-analogue (GnRHa) treatment on weight and body composition is controversial. Exploring the nutritional, psychological patterns of this population may aid to clarify this propensity to gain weight. This prospective observational study aimed to evaluate longitudinal changes in adiposity, nutrition and quality of life in girls with central precocious/early-fast puberty (CPP/EFP) during GnRHa treatment.

METHODS

Thirty-two GnRHa-treated girls with CPP/EFP and 27 prepubertal girls (7-10 years) were included in the analysis. Outcome measures assessed at baseline for CPP/EFP and the control groups and during up to two years of GnRHa treatment for the CPP/EFP group, included anthropometrics, body-composition, basal-metabolic-rate (BMR), 3-day food-diaries, child eating-behavior questionnaire, and pediatric quality-of-life questionnaire (PedsQL).

RESULTS

Girls with CPP/EFP had higher pretreatment BMI-SDS, fat percentages, waist circumference and waist-per-height (p<0.01 for all), and lower psychosocial functioning than controls (p<0.05). Changes in anthropometric and body composition measurements indicated a gradual increase in adiposity and a decrease in muscle mass (p<0.001 for all). Dynamics in body composition could not be explained by the participants' self-reported dietary patterns and physical activity levels or by the measured BMR, which revealed an adequate and relatively low energy intake as compared to energy requirements. A gradual decline in physical functioning (PedsQL) after one and two years of GnRHa treatment was observed (p<0.001).

CONCLUSIONS

Our findings highlight the need for comprehensive surveillance in girls with CPP/EFP. Dynamics in weight status and body composition during GnRHa treatment indicate the need for tailored nutritional and physical activity counseling aimed at preventing obesity.

Can skinfold thickness equations be substituted for bioimpedance analysis in children?

OBJECTIVE

The aim of the present study was to evaluate the agreement between the most used skinfold thickness equations with multi-frequency bioimpedance analysis in the prediction of body fat levels in children.

METHOD

A cross-sectional study of healthy Brazilian community-dwelling individuals. The anthropometric assessment included height, body mass, arm circumference, and waist circumference. The percentage of body fat was obtained by measuring skinfold thickness equations and using bioimpedance analysis, and skinfold thickness was measured using a scientific skinfold caliper. Bland-Altman plot analysis was used to verify the agreement between the methods.

RESULTS

There were 439 children and adolescents evaluated, with a mean age of 11.6±3.7 years. The mean body fat by bioimpedance analysis was 22.8%±10.4%, compared to 22.4%±8.8% by Slaughter (1), 20.4%±9.2% by Slaughter (2), 19.6%±4.4% by Goran, and 24.7%±10.0% by Huang equations. Bland-Altman plot analysis revealed limits of agreement greater than 8% between the bioimpedance analysis approach and equations, exceeding the clinically acceptable limit predefined a priori. None of the equations had good agreement with bioimpedance analysis.

CONCLUSION

It was concluded that skinfold thickness and bioimpedance analysis should not be used interchangeably in children and adolescents.

Relationship Between Plasma Copper Concentration and Body Fat Distribution in Children in China: a Cross-Sectional Study

This study aimed to explore the association of the plasma copper concentration with body fat distribution and the potential mediating effect of inflammation status in children. A total of 454 children were recruited in this study. Dual-energy X-ray absorptiometry was applied to measure the fat mass (FM) and fat mass percentages (FM%) at whole body, trunk, appendicular, android, and gynoid regions. Android to gynoid fat mass ratio and fat mass to lean mass (FM/LM) ratio at whole body, trunk, and appendicular sites were calculated. Plasma copper concentration was measured via inductively coupled plasma mass spectrometry. C-reactive protein (CRP) was determined by ELISA. After adjusting for covariates, multiple linear regression analyses showed that, for every additional unit increase in the plasma copper concentration, the FM, FM%, and FM/LM at whole body and subregions increased by 0.030-0.472 kg (P < 0.001-0.019), 0.013-1.04% (P = 0.007-0.042), and 0.021-0.030 (P < 0.001), respectively. Mediating analysis suggested that CRP significantly mediated 22.0-30.6% (P < 0.001) of the estimated association of copper with FM% and FM/LM at whole body and limbs. Thus, children with higher plasma levels of copper tended to have a higher regional and overall body fat deposition, and this relationship was partly mediated by inflammatory status.

Identification of the most appropriate existing anthropometric index for home-based obesity screening in children and adolescents

OBJECTIVES

Home-based self-screening and monitoring for obesity is particularly valuable for the prevention and control of chronic diseases. This study aimed to identify an anthropometric index suitable for home-based obesity screening in children and adolescents.

STUDY DESIGN

The design of this study is a cross-sectional study.

METHODS

A total of 14,042 students (6-17 years) from the Qibao Community, Minhang District, Shanghai, were studied in 2018. The percentage body fat (PBF), height, weight, waist circumference (WC) and hip circumference were measured. Body mass index (BMI), triponderal mass index (TMI), body adiposity index (BAI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. Partial correlation analysis was used to evaluate the relationships between these indices and PBF, and receiver operating characteristic (ROC) curves were used to evaluate their performance for obesity screening.

RESULTS

BMI, TMI, WC and WHtR were found to strongly correlate with PBF (r ≥ 0.830, all P < 0.001). The optimal index for obesity screening in children (6-11 years) was BMI (area under the ROC curve [AUC] = 0.980 for boys and 0.981 for girls) and in adolescents (12-17 years) was TIM (AUC = 0.976 for boys and 0.945 for girls); however, the optimal cut-off values for BMI and TMI differed among the subgroups. The ROC curve analysis showed that WHtR had similar cut-off values in each subgroup (0.45 for boys of 6-11 years and 0.43 for the other subgroups), excellent performance in children (AUC>0.90) and good performance in adolescents (AUC = 0.960 for girls and 0.878 for boys).

CONCLUSIONS

Owing to its accuracy and stable cut-off value for defining obesity, WHtR should be recommended for home-based obesity screening in children and adolescents.

Changes in body composition by age and obesity status in preschool-aged children: the STEPS study

BACKGROUND/OBJECTIVES

Obesity in early childhood is associated with increased risk of chronic diseases, but studies of body composition at preschool ages are sparse. Therefore, we examined differences in body composition by sex and obesity status in Finnish preschool-aged children and within-individual changes in body composition in normal and overweight children.

SUBJECT/METHODS

Body composition was measured using segmental multifrequency bioimpedance analysis (BIA) in 476 children and in 781 children at age 3 and 5 years, respectively. Of those, 308 had repeated BIA measurements at both ages. BMI-SDS was used for classification of normal weight and overweight children.

RESULTS

Sex difference in the amount of lean mass (LM) was already seen at 3 years of age (boys 11.7 kg, girls 11.3 kg; p < 0.001). At 5 years of age, boys had lower fat mass (FM; 3.6 kg vs. 3.9 kg, p < 0.001), lower percent fat mass (%FM; 17.2% vs. 19.1%; p < 0.001), and higher LM (16.0 kg vs. 15.2 kg; p < 0.001) than girls. Overweight children had higher values in FM, %FM, and LM compared with normal weight peers at both ages. Among normal weight children, the increase of LM by age was associated with only minor changes in FM, whereas children who were or became overweight both LM and FM was substantially increased between 3 and 5 years of age.

CONCLUSIONS

BIA-assessed body composition differs by sex and obesity status already at age of 3 years. For children who are or become overweight at very young age, the patterns for the changes in LM and FM by age are different than for normal weight children.

Relação entre composição corporal e dislipidemias em crianças e adolescentes

Resumo Verificou-se a relação entre diferentes índices antropométricos e os lipídios plasmáticos. Os dados foram coletados de 2014 a 2016 em 854 escolares (6-18 anos). Foram aferidas a circunferência da cintura (CC), o percentual de gordura corporal (%G) por bioimpedância, o índice de massa corporal (IMC) e relação da cintura/estatura (RCE). Em sangue coletado em jejum mediu-se o colesterol total (CT), HDLc, e triglicerídeos e calculou-se o colesterol não HDL (Não HDLc). Os dados são apresentados por média ± desvio padrão, porcentagens. A comparação de médias foi feita pelo teste t ou ANOVA seguida de teste de Tukey. A associação entre variáveis foi testada por regressão linear. O estudo foi aprovado pelo Comitê de Ética da Universidade Federal do Espírito Santo. Meninos obesos tinham CT, Não HDLc e LDLc mais elevados do que os eutróficos. Em meninas este achado foi apenas para o Não HDLc. Crianças com o %G e RCE inadequados apresentaram LDLc e Não HDLc maiores (p < 0,001), os quais associaram-se positivamente (p < 0,001) com as frações lipídicas (CT e Não HDLc). O excesso de gordura corporal elevou em 21% a probabilidade de ocorrência de colesterol acima da referência (170 mg/dL). O excesso de gordura corporal associou-se com o perfil lipídico aterogênico (maior Não HDLc), principalmente em meninos.

Child-care self-assessment to improve physical activity, oral health and nutrition for 2- to 4-year-olds: a feasibility cluster RCT

Background

The Nutrition And Physical Activity Self Assessment for Child Care (NAP SACC) intervention has shown evidence of effectiveness in the USA but not been adapted or assessed for effectiveness in the UK.

Objectives

To evaluate the feasibility and acceptability of implementing NAP SACC in the UK.

Design

Adaptation and development of NAP SACC and feasibility cluster randomised controlled trial (RCT) including process and economic evaluations. Substudies assessed mediator questionnaire test–retest reliability and feasibility of food photography methods.

Setting

Nurseries, staff and parents in North Somerset, Cardiff, Gloucestershire and Bristol.

Participants

Development – 15 early years/public health staff and health visitors, 12 nursery managers and 31 parents. RCT – 12 nurseries and 31 staff, four partners and 168 children/parents. Mediator substudy – 82 parents and 69 nursery staff. Food photography substudy – four nurseries, 18 staff and 51 children.

Intervention

NAP SACC UK partners supported nurseries to review policies and practices and set goals to improve nutrition, oral health and physical activity (PA) over 5 months. Two workshops were delivered to nursery staff by local experts. A home component [website, short message service (SMS) and e-mails] supported parents. The control arm continued with usual practice.

Main outcome measures

Feasibility and acceptability of the intervention and methods according to prespecified criteria.

Data sources

Qualitative data to adapt the intervention. Measurements with children, parents and staff at baseline and post intervention (8–10 months after baseline). Interviews with nursery managers, staff, parents and NAP SACC UK partners; observations of training, workshops and meetings. Nursery environment observation, nursery Review and Reflect score, and resource log. Child height and weight, accelerometer-determined PA and sedentary time, screen time and dietary outcomes using the Child and Diet Evaluation Tool. Staff and parent questionnaires of knowledge, motivation and self-efficacy. Child quality of life and nursery, family and health-care costs. Food photography of everything consumed by individual children and staff questionnaire to assess acceptability.

Results

Thirty-two per cent (12/38) of nurseries and 35.3% (168/476) of children were recruited; no nurseries withdrew. The intervention was delivered in five out of six nurseries, with high levels of fidelity and acceptability. Partners found it feasible but had concerns about workload. The child loss to follow-up rate was 14.2%. There was suggestion of promise in intervention compared with control nurseries post intervention for snacks, screen time, proportion overweight or obese and accelerometer-measured total PA and moderate to vigorous PA. Many parental and nursery knowledge and motivation mediators improved. The average cost of delivering the intervention was £1184 per nursery excluding partner training, and the average cost per child was £27. Fourteen per cent of parents used the home component and the mediator questionnaire had good internal consistency and test–retest reliability. Photography of food was acceptable and feasible.

Limitations

Following nursery leavers was difficult. Accelerometer data, diet data and environmental assessment would have been more reliable with 2 days of data.

Conclusions

The NAP SACC UK intervention and methods were found to be feasible and acceptable to participants, except for the home component. There was sufficient suggestion of promise to justify a definitive trial.

Future work

A multicentre cluster randomised controlled trial to evaluate the effectiveness and cost-effectiveness of NAP SACC UK has been funded by NIHR and will start in July 2019 (PHR NIHR 127551).

Trial registration

Current Controlled Trials ISRCTN16287377.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 7, No. 13. See the NIHR Journals Library website for further project information. Funding was also provided by the North Somerset and Gloucestershire Councils, Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer) (MR/KO232331/1), and the Elizabeth Blackwell Institute.

The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials

The clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I² index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95% CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m²; 95% CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95% CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (≥8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (≥8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index.

Anthropometric and clinical correlates of fat mass in healthy term infants at 6 months of age

BACKGROUND

Body composition in infancy plays a central role in the programming of metabolic diseases. Fat mass (FM) is determined by personal and environmental factors. Anthropometric measurements allow for estimations of FM in many age groups; however, correlations of these measurements with FM in early stages of life are scarcely reported. The aim of this study was to evaluate anthropometric and clinical correlates of FM in healthy term infants at 6 months of age.

METHODS

Healthy term newborns (n = 102) from a prospective cohort. Weight, length, skinfolds (biceps, triceps, subscapular and the sum -SFS-) and waist circumference (WC) were measured at 6 months. Body mass index (BMI) and WC/length ratio were computed. Type of feeding during the first 6 months of age was recorded. Air displacement plethysmography was used to asses FM (percentage -%-) and FM index (FMI) was calculated. Correlations and general linear models were performed to evaluate associations.

RESULTS

Significant correlations were observed between all anthropometric measurements and FM (% and index)(p < 0.001). Exclusive/predominant breastfed infants had higher FM and anthropometric measurements at 6 months. Models that showed the strongest associations with FM (% and index) were SFS + WC + sex + type of feeding.

CONCLUSIONS

Anthropometry showed good correlations with FM at 6 months of age. Skinfolds sum and waist circumference were the strongest anthropometric variables associated to FM. Exclusive/predominant breastfeeding was strongly associated with FM.

Body mass index classification misses to identify children with an elevated waist-to-height ratio at 5 years of age

BACKGROUND

Abdominal adiposity is an important risk factor in the metabolic syndrome. Since BMI does not reveal fat distribution, waist-to-height ratio (WHtR) has been suggested as a better measure of abdominal adiposity in children, but only a few studies cover the preschool population. The aim of the present study was to examine BMI and WHtR growth patterns and their association regarding their ability to identify children with an elevated WHtR at 5 years of age.

METHODS

A population-based longitudinal birth cohort study of 1540 children, followed from 0 to 5 years with nine measurement points. The children were classified as having WHtR standard deviation scores (WHtR_SDS) <1 or ≥1 at 5 years. Student's t-tests and Chi-squared tests were used in the analyses.

RESULTS

Association between BMI_SDS and WHtR_SDS at 5 years showed that 55% of children with WHtR_SDS ≥1 at 5 years had normal BMI_SDS (p < 0.001). Children with WHtR_SDS ≥1 at 5 years had from an early age significantly higher mean BMI_SDS and WHtR_SDS than children with values <1.

CONCLUSIONS

BMI classification misses every second child with WHtR_SDS ≥1 at 5 years, suggesting that WHtR adds value in identifying children with abdominal adiposity who may need further investigation regarding cardiometabolic risk factors.

Performance of Waist-To-Height Ratio, Waist Circumference, and Body Mass Index in Discriminating Cardio-Metabolic Risk Factors in a Sample of School-Aged Mexican Children

The most common tools used to screen for abdominal obesity are waist circumference (WC) and waist-to-height ratio (WHtR); the latter may represent a more suitable tool for the general non-professional population. The objective of this study was to evaluate the association of WHtR, WC, and body mass index with lipidic and non-lipidic cardio-metabolic risk factors and the prediction capability of each adiposity indicator in a sample of school-aged Mexican children. Overall, 125 children aged 6 to 12 years were analyzed. Anthropometric, biochemical, and dietary parameters were assessed. Receiving operating characteristic (ROC) analysis and univariate and multivariate linear and logistic regression analyses were performed. All the three adiposity indicators showed significant areas under the ROC curve (AURC) greater than 0.68 for high low-density lipoprotein cholesterol (LDL-c), triglycerides, and atherogenic index of plasma, and low high-density lipoprotein cholesterol (HDL-c). A significant increased risk of having LDL-c ≥ 3.4 mmol/L was observed among children with WHtR ≥ 0.5 as compared to those with WHtR < 0.5 (odds ratio, OR: 2.82; 95% confidence interval, CI: 0.75–7.68; p = 0.003). Fasting plasma glucose was not associated with any of the adiposity parameters. WHtR performed similarly to WC and z-BMI in predicting lipidic cardio-metabolic risk factors; however, a WHtR ≥ 0.5 was superior in detecting an increased risk of elevated LDL-c.

Correlation of salivary immunoglobulin A with Body Mass Index and fat percentage in overweight/obese children

Obesity is considered a risk factor for periodontal health due to the low- grade inflammation promoted by the increased adipose tissue.

OBJECTIVE

This study aimed to determine correlations and associations between gingival inflammation (Simplified Oral Hygiene Index, and Gingival Index), salivary immunoglobulin A (s-IgA), and salivary parameters (salivary flow and osmolality) in normal-weight and overweight/obese children.

MATERIAL AND METHODS

Ninety-one children, aged 6 to 12 years old (8.6±1.9 years), were divided into two groups according to their body mass index (BMI), circumferences, skinfold measurements and body fat percentage: normal- weight group (NWG; n =50) and overweight/obese group (OG; n =41). A calibrated examiner performed the clinical examination using the Simplified Oral Hygiene Index, Gingival Index, and salivary collection. Data analysis included descriptive statistics and association tests ( p <0.05).

RESULTS

OG presented statistically higher s-IgA values compared with NWG, especially among the obese children ( p <0.05). Significant positive correlations between s-IgA and salivary osmolality in OG ( p <0.05), and between s-IgA and BMI values ( p <0.05) and body fat percentage ( p <0.05) were observed among all the children. Effect size varied from moderate for s-IgA values ( d =0.57) to large for BMI ( d =2.60).

CONCLUSION

Gingival inflammation and salivary parameters were similar for NWG and OG; however, s-IgA presented higher values in OG, with correlations between BMI and body fat percentage.

Comparing BMI with skinfolds to estimate age at adiposity rebound and its associations with cardio-metabolic risk markers in adolescence

Background

Body mass index (BMI) reaches a nadir in mid-childhood, known as the adiposity rebound (AR). Earlier AR is associated with a higher risk of cardio-vascular diseases in later life. Skinfolds, which are a more direct measure of adiposity, may give better insight into the relationship between childhood adiposity and later obesity and cardio-metabolic risk.

Objective

We aimed to assess whether AR corresponds to a rebound in skinfolds, and compare associations of BMI-derived AR and skinfold-derived AR with cardio-metabolic risk markers in adolescence.

Methods

We used penalised splines with random coefficients to estimate BMI and skinfold trajectories of 604 children from the Mysore Parthenon Birth Cohort. Age at AR was identified using differentiation of the BMI and skinfold growth curves between 2 and 10 years of age. At 13.5 years, we measured blood pressure, and glucose, insulin and lipid concentrations.

Results

BMI and skinfolds had different growth patterns. Boys reached BMI-derived AR earlier than skinfold-derived AR (estimated difference: 0.41 years; 95% CI:[0.23, 0.56]), whereas the opposite was observed in girls (estimated difference: −0.71 years; 95% CI:[−0.90, −0.54]). At 13.5 years, children with earlier BMI-derived AR had higher BMI (−0.58 SD per SD increase of AR; 95%CI:[−0.65, −0.52]), fat mass (−0.44; 95%CI:[−0.50, −0.37]), insulin resistance (HOMA-IR: −0.20; 95%CI:[−0.28, −0.12]) and systolic blood pressure (−0.20; 95%CI:[−0.28, −0.11]), and lower HDL-cholesterol (0.12; 95%CI:[0.04, 0.21]). The associations were independent of BMI at time of rebound, but were fully explained by fat mass at 13.5 years. Similar associations were found for skinfold-derived AR.

Conclusion

BMI-derived adiposity rebound predicts later cardio-metabolic risk markers similarly to that derived from skinfolds, a direct measure of adiposity.

Waist-to-height ratio as a risk marker for metabolic syndrome in childhood. A meta-analysis

BACKGROUND

Individuals with abdominal obesity have a higher cardiovascular risk, regardless of the degree of global overweight.

OBJECTIVE

To estimate the accuracy of the Waist/height ratio (WtHR) as a risk marker for metabolic syndrome (MS) in children or adolescents.

METHODS

Published cohort or cross-sectional studies (Pubmed, Embase-SCOPUS and CINAHL) were searched, with no limits of time. Studies providing Waist/height ratio and clustered criteria of metabolic syndrome were included.

RESULTS

Thirty-one studies (66,912 subjects) were selected. Overall, a high WtHR (≥0.5) was associated with a four-fold increased risk of clustered criteria of MS (odds ratio [OR] 4.15, 95% confidence interval [95% CI]: 2.69 to 6.42) and two-fold increased risk when adjusted by general obesity (adjusted OR 2.26, 95% CI: 1.29 to 3.98). The WtHR, as a quantitative measure, showed a pooled area under the curve of 0.76 (95% CI: 0.71 to 0.80) and, as a dichotomous measure, with a cut-off point close to 0.5, a sensitivity of 60% (95% CI: 50% to 68.8%) and a specificity of 79% (95% CI: 71.6% to 83.9%).

CONCLUSIONS

Measuring WtHR may be considered in regular health checks of children and adolescents, as it can measure cardiovascular risk regardless of the degree of general obesity.

Percent of body fat, fat-mass, fat-free mass and assessment of body composition among rural school-going children of Eastern-India

Percent of body fat (PBF), fat mass (FM) and fat free mass (FFM) are useful indicators for the assessment of body composition. The present study was conducted among 1351 children (boys: 660; girls: 691) aged 5–12 years residing in West Bengal, Eastern-India. The children were selected using a stratified random sampling method. Anthropometric measurements of height, weight, triceps skinfold (TSF) and sub-scapular skinfold (SSF) were recorded using standard procedures. The PBF, PBF-for-age z-score (PBFZ) and body mass index (BMI) were subsequently calculated. Body composition was assessed using FM, FFM, fat mass index (FMI) and fat free mass index (FFMI). Age-specific mean values of FM ranged from 2.12–4.00 kg (boys) and 2.16–4.40 kg (girls). Age-specific mean values of FFM ranged from 14.45–23.93 kg (boys) and 14.01–23.03 kg (girls). Sex-specific mean differences between sexes were statistically significant in weight, height, TSF, SSF, PBF, PBFAZ, FM, FFM, FMI and FFMI (p<0.05), except in BMI (p>0.05). These results are important for future investigations in clinical and epidemiological settings so as to accurately identify the risk of lower or higher adiposity and body composition using PBF, FM and FFM.

Assessing truncal obesity in predicting cardiometabolic risk in children: clinical measures versus dual-energy X-ray absorptiometry

AIM

The objectives of this study were to 1) compare the accuracy of waist:hip ratio (WHR) and waist:height ratio (WHtR) by determining their association with reference-standard measures derived from dual-energy X-ray absorptiometry (DXA) and 2) assess the relationship of DXA, WHR and WHtR to measures of dyslipidemia, insulin resistance and inflammation in children.

METHODS

Subjects aged four to 21 were prospectively recruited. Truncal obesity by DXA was defined as the trunk fat:height ratio and trunk fat:nontrunk fat ratio. Three hundred and eight subjects were studied, and 246 (80%) were obese.

RESULTS

There was a strong correlation between WHtR and trunk fat:height (r = 0.84, p < 0.01). DXA measures of truncal obesity had stronger correlations with measures of cardiometabolic risk than WHR and WHtR. Upon multivariable regression, only WHtR had independent associations with cholesterol/HDL, HOMA-IR and high-sensitivity c-reactive protein.

CONCLUSION

WHtR is an accurate measure of truncal obesity. WHtR showed stronger associations with measures of insulin resistance and truncal obesity than WHR.

PEDIATRIC VISCERAL ADIPOSITY INDEX ADAPTATION CORRELATES WITH HOMA-IR, MATSUDA, AND TRANSAMINASES

OBJECTIVE

Visceral adiposity index (VAI) is a mathematical model associated with cardiometabolic risk in adults, but studies on children failed to support this association. Our group has proposed a pediatric VAI model using pediatric ranges, but it has not yet been evaluated and needs further adjustments. The objective of this study was to further adjust the proposed pediatric VAI by age, creating a new pediatric metabolic index (PMI), and assess the correlation of the PMI with insulin resistance indexes and hepatic enzymes.

METHODS

A cross-sectional design with data from 396 children (age 5 to 17 years) was analyzed with a generalized linear model to find the coefficients for triglycerides, high-density-lipoprotein cholesterol, and waist circumference-body mass index quotient. The model was constructed according to sex and age and designated PMI. A cross-validation analysis was performed and a receiver operating characteristic curve was used to determine cut-off points.

RESULTS

Significant moderate correlation was found between PMI and homeostatic model assessment of insulin resistance (HOMA-IR) ( r = 0.452; P = .003), Matsuda ( r = -0.366; P = .019), alanine aminotransferase ( r = 0.315, P = .045), and γ-glutamyltransferase ( r = 0.397; P = .010). A PMI score >1.7 was considered as risk.

CONCLUSION

PMI correlates with HOMA-IR, Matsuda, and hepatic enzymes. It could be helpful for identifying children at risk for cardiometabolic diseases.

ABBREVIATIONS

ALT = alanine transaminase BMI = body mass index GGT = γ-glutamyltransferase HDL-C = high-density-lipoprotein cholesterol HOMA-IR = homeostatic model assessment of insulin resistance hs-CRP = high sensitivity C-reactive protein ISI = insulin sensitivity index NAFLD = nonalcoholic fatty liver disease PMI = pediatric metabolic index QUICKI = quantitative insulin sensitivity check index ROC = receiver operating characteristic TG = triglyceride TNF-α = tumor necrosis factor-alpha VAI = visceral adiposity index VAT = visceral adipose tissue WC = waist circumference.

Waist circumference in 6–12-year-old children: The Health Oriented Pedagogical Project (HOPP)

Aims: With overweight and obesity increasing worldwide, it has become ever more important to monitor the development and distribution of adiposity in children. This study investigated how the measurements of waist circumference (WC) and waist-to-height ratio (WHtR) in children 6–12 years old relate to earlier studies. Methods: In 2015, 2271 children (boys, n = 1150) were measured for height, weight, and WC. Parental education level was used as a measure of socioeconomic status. Results: A significant increase in WC with age was revealed for both sexes ( p < .0001). Boys at 10 and 12 years had a larger WC than girls; otherwise no difference between sexes was found. The WHtR decreased with age for girls ( p < .0001); 14% of the sample displayed a WHtR ≥ 0.50. Comparison with earlier studies showed a higher WC and WHtR despite no change in weight and body mass index. Conclusion: WC and WHtR are recommended as tools for identifying central obesity in children. The results indicate increased WC in 6–12-year-old children compared with earlier findings.

Neck Circumference Percentiles of Iranian Children and Adolescents: The Weight Disorders Survey of CASPIAN IV Study

BACKGROUND

Neck circumference (NC), emerging as a key morphological index for pediatric obesity, is associated with obesity- and overweight-related detrimental conditions in children. In this study, we aimed to provide the age- and sex-specific percentile reference values for neck circumference of the Iranian children and adolescents.

METHODS

We used the data gathered through the weight disorders survey of CASPIAN IV study conducted in 2011 - 2012 in Iran, including a total of 21954 Iranian children and adolescents, composed of 10750 girls and 11204 boys, aged 7 - 18 years old. We presented the interval of NC percentile in three age groups of 7 - 10 years, 11 - 14 years, and 15 - 18 years. Finally, age-specific nomograms of NC for both genders in the Iranian and Canadian populations were compared.

RESULTS

The intervals of 90th percentile of NC for boys in the three periods of school age (7 - 10 years), pre-adolescence (11 - 14 years), and adolescence (15 - 18 years) were 24.2 - 30.0 cm, 26.6 - 33.2 cm, and 30.1 - 38.5 cm, respectively. These intervals for girls were 23.7 - 30.1 cm, 26.5 - 33.7 cm, and 28.5 - 36.0 cm, respectively. NC increased with age in both boys and girls and its variability showed an increasing trend with age.

CONCLUSIONS

We demonstrated for the first time the NC reference values for the Iranian children and adolescents aged 7 - 18 years old. Considering the significant differences between our national NC references and the values reported from the Canadian population, it seems logical to use these national percentiles not only for epidemiologic studies but also for routine clinical examinations.

A simple equation to estimate body fat percentage in children with overweightness or obesity: a retrospective study

Background

Dual-energy X-ray absorptiometry (DXA) provides separate measurements of fat mass, fat-free mass and bone mass, and is a quick, accurate, and safe technique, yet one that is not readily available in routine clinical practice. Consequently, we aimed to develop statistical formulas to predict fat mass (%) and fat mass index (FMI) with simple parameters (age, sex, weight and height).

Methods

We conducted a retrospective observational cross-sectional study in 416 overweight or obese patients aged 4–18 years that involved assessing adiposity by DXA (fat mass percentage and FMI), body mass index (BMI), sex and age. We randomly divided the sample into two parts (construction and validation). In the construction sample, we developed formulas to predict fat mass and FMI using linear multiple regression models. The formulas were validated in the other sample, calculating the intraclass correlation coefficient via bootstrapping.

Results

The fat mass percentage formula had a coefficient of determination of 0.65. This value was 0.86 for FMI. In the validation, the constructed formulas had an intraclass correlation coefficient of 0.77 for fat mass percentage and 0.92 for FMI.

Conclusions

Our predictive formulas accurately predicted fat mass and FMI with simple parameters (BMI, sex and age) in children with overweight and obesity. The proposed methodology could be applied in other fields. Further studies are needed to externally validate these formulas.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity and Metabolic Syndrome among Korean Children and Adolescents: Korea National Health and Nutrition Examination Survey, 2010-2014

The aims of this study were to assess the diagnostic value of the weight-to-height ratio (WHtR) for the detection of obesity and metabolic syndrome (MS) in Korean children and adolescents, and to determine the advantages of WHtR as a population-based screening tool in comparison with other obesity indicators, such as body mass index (BMI) and waist circumference (WC). We performed a cross-sectional analysis of data from 3057 children and adolescents (1625 boys, 1332 girls) aged 10-19 years who were included in the fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2012) up to the second year of the sixth KNHANES (2013-2014). Receiver operation characteristic (ROC) curves were generated to determine the optimal cutoff value and accuracy of WHtR for predicting individual obesity indicators or more than two non-WC components of MS. The area under the ROC curve (AUC) is a measure of the diagnostic power of a test. A perfect test will have an AUC of 1.0, and an AUC equal to 0.5 means that the test performs no better than chance. The optimal WHtR cutoff for the evaluation of general obesity and central obesity was 0.50 in boys and 0.47-0.48 in girls, and the AUC was 0.9. Regarding the assessment of each MS risk factor, the optimal WHtR cutoff was 0.43-0.50 in boys and 0.43-0.49 in girls, and these cutoffs were statistically significant only for the detection of high triglyceride and low High-density lipoprotein (HDL) cholesterol levels. When a pairwise comparison of the AUCs was conducted between WHtR and BMI/WC percentiles to quantify the differences in power for MS screening, the WHtR AUC values (boys, 0.691; girls, 0.684) were higher than those of other indices; however, these differences were not statistically significant (boys, p = 0.467; girls, p = 0.51). The WHtR cutoff value was 0.44 (sensitivity, 67.7%; specificity, 64.6%) for boys and 0.43 (sensitivity, 66.4%; specificity, 66.9%) for girls. There was no significant difference between the diagnostic power of WHtR and that of BMI/WC when screening for MS. Although the use of WHtR was not superior, WHtR is still useful as a screening tool for metabolic problems related to obesity because of its convenience.

Waist-to-height ratio as a screening tool for obesity and cardiometabolic risk

The waist-to-height ratio (WHtR), calculated by dividing the waist circumference (WC) by height, has recently gained attention as an anthropometric index for central adiposity. It is an easy-to-use and less age-dependent index to identify individuals with increased cardiometabolic risk. A WHtR cutoff of 0.5 can be used in different sex and ethnic groups and is generally accepted as a universal cutoff for central obesity in children (aged ≥6 years) and adults. However, the WHtR has not been validated in preschool children, and the routine use of WHtR in children under age 6 is not recommended. Prospective studies and meta-analysis in adults revealed that the WHtR is equivalent to or slightly better than WC and superior to body mass index (BMI) in predicting higher cardiometabolic risk. In children and adolescents, studies have shown that the WHtR is similar to both BMI and WC in identifying those at an increased cardiometabolic risk. Additional use of WHtR with BMI or WC may be helpful because WHtR considers both height and central obesity. WHtR may be preferred because of its simplicity and because it does not require sex- and age-dependent cutoffs; additionally, the simple message 'keep your WC to less than half your height' may be particularly useful. This review article summarizes recent publications on the usefulness of using WHtR especially when compared to BMI and WC as a screening tool for obesity and related cardiometabolic risks, and recommends the use of WHtR in clinical practice for obesity screening in children and adolescents.