Análisis de la composición corporal por parámetros antropométricos y bioeléctricos

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.

Early Risk Factors for Obesity in the First 1000 Days-Relationship with Body Fat and BMI at 2 Years

(1) Background: Obesity is defined as an excessive accumulation of body fat. Several early developmental factors have been identified which are associated with an increased risk of childhood obesity and increased adiposity in childhood. The primary objective of the present study is to analyse the effect of various early risk factors on Body Mass Index (BMI) and body fat percentage at 2 years of age. (2) Methods: A prospective cohort study design was used, with the sample consisting of 109 mother-child pairs from whom data were collected between early pregnancy and 2 years old. Adiposity was determined based on skinfold measurements using the Brooks and Siri formulae. Mean comparison tests (Student's t-test and ANOVAs) and multiple linear regression models were used to analyse the relationship between early programming factors and dependent variables. (3) Results: Maternal excess weight during early pregnancy (β = 0.203, p = 0.026), gestational smoking (β = 0.192, p = 0.036), and accelerated weight gain in the first 2 years (β = - 0.269, p = 0.004) were significantly associated with high body fat percentage. Pre-pregnancy BMI and accelerated weight gain in the first 2 years were associated with high BMI z-score (β = 0.174, p = 0.047 and β = 0.417, p = 0.000 respectively). The cumulative effect of these variables resulted in high values compared to the baseline zero-factor group, with significant differences in BMI z-score (F = 8.640, p = 0.000) and body fat percentage (F = 5.402, p = 0.002) when three factors were present. (4) Conclusions: The presence of several early risk factors related to obesity in infancy was significantly associated with higher BMI z-score and body fat percentage at 2 years of age. The presence of more than one of these variables was also associated with higher adiposity at 2 years of age. Early prevention strategies should address as many of these factors as possible.

Body composition in a population of school adolescents: a comparison of simple anthropometric methods and bioelectrical impedance

OBJECTIVES

To report the anthropometric characteristics and body composition and to analyze the potential sex-based differences in Spanish schoolchildren and adolescents living in Granada and Ceuta. To estimate body fat percentage using regression equations and bioelectrical impedance to check for sex differences. An additional objective was to see whether the body fat percentages obtained by these two methods were similar.

METHODS

A cross-sectional study including 1,518 children and adolescents (aged 9-16) from 12 primary and secondary schools in Ceuta and Granada. The nutritional status of the subjects was assessed and their body fat percentage was calculated.

RESULTS

There was a strong sexual dimorphism, with higher prevalence rates of overweight in boys and obesity in girls. Girls had higher mean body fat levels regardless of the measuring method used (p<.001). Correlation between bioelectrical impedance analysis and regression equations was high (r=0.830), as was the internal correlation coefficient (ICC>0.75). A Bland-Altman comparison showed a high agreement between bioelectrical impedance and Behnke and Lohman equations.

CONCLUSIONS

Specific equations considering subject sex and age should be used to estimate body density. Regardless of the method used, girls had higher body fat percentages. The Behnke and Lohman equations, combined with BIA, were found to be the most accurate methods for measuring body density in the study population.

Body Composition Assessment and Nutritional Status Evaluation in Men and Women Portuguese Centenarians

OBJECTIVES

To assess body composition, nutritional status and its differences between genders in a sample of Portuguese centenarians.

DESIGN

Observational cross-sectional study.

SETTING

Centenarians recruited in Portugal, able to give informed consent.

PARTICIPANTS

A total of 252 subjects, with a median age of 100 years, mostly women (77.8%) who accepted to participate in the study, during the period of 2012 to 2014.

MEASUREMENTS

Anthropometric data collected (weight, height, BMI, waist circumference, hip and waist/hip ratio) were evaluated according to WHO criteria. A portable tetrapolar bioimpedance analyzer was used to calculate body composition and to assess resting metabolism. Nutritional status was evaluated according to three different criteria: BMI, waist circumference and body fat percentage using anthropometric equations and bioimpedance.

RESULTS

We observed an overall mean weight of 51.02±11.03Kg, height of 1.55±0.07m and a BMI of 21.07±3.69Kg/m2. For most of the evaluated parameters, we found substantial differences between genders. The prevalence of underweight and overweight were 25.3% and 13.3%, respectively. Only 5 subjects were obese. Overweight subjects were mostly men (W=10.6% vs. M=22.6%), whereas women were more underweight (W=28.7% vs. M=13.2%). When considering the waist circumference, 26.5% were above the cut-off value. Most of centenarians (72.9%) had a healthy level of visceral fat. This measurement was highly correlated with waist circumference (r= 0.687, p<0.001). The mean of body fat mass was 10.69±6.50Kg, fat-free mass 40.87±7.60Kg and total body water 27.54±6.25Kg. According to body fat mass criteria assessed by bioimpedance, the prevalence of obesity in study population was 6.0% with no gender differences (p = 0.225). Obesity prevalence using anthropometric equations was higher (Deurenberg: 77.7% and Gallagher: 42.8%) than the obtained value by bioimpedance analysis, although according to Bland-Altman analysis both equations showed a good agreement (Deurenberg: 95.8% and Gallagher: 97%) with bioimpedance method. The prevalence of hypohydration (12.9%) was tendentiously higher in women compared to men (W= 15.4% vs. M= 5.0%, p=0.087). Despite the frequency of osteoporosis was higher in women (W = 71.85% vs. M = 28.15%), 95% of men revealed criteria for osteoporosis. Resting metabolic rate (RMR) was significantly different between genders using bioimpedance analysis (W= 1123.33± 173.91; M= 1350.10± 188.88; p<0.001) or Harris Benedict equation (W= 934.92± 102.60; M= 1018.85± 171.68; p=0.001). Bland- Altman analysis between methods indicate that there was an agreement of 97.6%. The overall mean metabolic age obtained was 83.52±1.11 years, well below the chronologic age (p<0.001).

CONCLUSION

In Portuguese centenarians, clinical and nutritional approach should be improved on the gender basis. In relation to nutritional status, centenarians were more frequently underweight than overweight. The thinness could be a natural process, contributing for the longevity being rather overweight a reducing factor in life expectancy. BMI and waist circumference showed a good correlation with body fat percentage. Despite the results of Bland- Altman analysis, Deurenberg and Gallagher equations are not suitable to evaluate obesity prevalence in centenarians. Harris Benedict equation seems to be a good option to measure RMR in centenaries, when BIA is not available. Body composition and nutritional characterization of Portuguese centenarians are relevant contribution in scientific evidence production for the action plan of healthy ageing in Europe (2012-2020) and also for clinical practice.

Activity Begins in Childhood (ABC) - inspiring healthy active behaviour in preschoolers: study protocol for a cluster randomized controlled trial

Background

Today’s children are more overweight than previous generations and physical inactivity is a contributing factor. Modelling and promoting positive behaviour in the early years is imperative for the development of lifelong health habits. The social and physical environments where children spend their time have a powerful influence on behaviour. Since the majority of preschool children spend time in care outside of the home, this provides an ideal setting to examine the ability of an intervention to enhance movement skills and modify physical activity behaviour. This study aims to evaluate the efficacy of the Activity Begins in Childhood (ABC) intervention delivered in licensed daycare settings alone or in combination with a parent-driven home physical activity-promotion component to increase preschoolers’ overall physical activity levels and, specifically, the time spent in moderate to vigorous physical activity.

Methods/design

This study is a single site, three-arm, cluster-randomized controlled trial design with a daycare centre as the unit of measurement (clusters). All daycare centres in the National Capital region that serve children between the ages of 3 and 5, expressing an interest in receiving the ABC intervention will be invited to participate. Those who agree will be randomly assigned to one of three groups: i) ABC program delivered at a daycare centre only, ii) ABC program delivered at daycare with a home/parental education component, or iii) regular daycare curriculum. This study will recruit 18 daycare centres, 6 in each of the three groups. The intervention will last approximately 6 months, with baseline assessment prior to ABC implementation and follow-up assessments at 3 and 6 months.

Discussion

Physical activity is an acknowledged component of a healthy lifestyle and childhood experiences as it has an important impact on lifelong behaviour and health. Opportunities for physical activity and motor development in early childhood may, over the lifespan, influence the maintenance of a healthy body weight and reduce cardiovascular disease risk. If successful, the ABC program may be implemented in daycare centres as an effective way of increasing healthy activity behaviours of preschoolers.

Trial registration

Current Controlled Trials: ISRCTN94022291. Registered in December 2012, first cluster randomized in April 2013.

Does body mass index accurately reflect body fat? A comparison of anthropometric measures in the longitudinal assessment of fat mass

OBJECTIVE

To determine which anthropometric measure best correlates with change in fat mass (FM) over time.

METHODS

The authors performed a retrospective cohort study of 76 obese patients (mean body mass index [BMI] 38 kg/m(2) and mean age 13 years) presenting to an obesity clinic between 2005 and 2010. For each patient, during 2 visits, FM was measured by bioelectrical impedance analysis and the following measures obtained: BMI, waist circumference, hip circumference, and neck circumference. Correlation coefficients and linear regression analyses were calculated to examine the relationship between each measure and FM.

RESULTS

Change in BMI correlated better with change in FM than any other measure and had the strongest effect on change in FM (P < .01, R (2) = .887). The best regression model included BMI only (R (2) = .891); without BMI, the model was significantly worse (R (2) = .521).

DISCUSSION

In the clinical management of obese children, BMI is an adequate measure of change in FM.

Physical activity promotion in the preschool years: a critical period to intervene

The primary aim of this paper is to provide a rationale for the necessity of intervening with a physical activity intervention in the preschool years and why the daycare environment is amenable to such intervention. We also review the prevalence of physical activity, sedentary behaviour and obesity in the preschool population and the impact that these lifestyle behaviours and conditions have on the health of preschool aged children, as secondary objectives. Moreover we discuss implications for intervention and research using a "lessons learned" model based on our research team's experience of conducting a randomized controlled trial aimed at increasing physical activity, reducing sedentary behaviour and improving motor skill development and body composition in preschoolers. Lastly, we make conclusions based on the literature and highlight issues and directions that need to be addressed in future research in order to maximize health promotion and chronic disease prevention in the pediatric population.