A novel body circumferences-based estimation of percentage body fat

Adult obesity diagnostic tool: A narrative review

Obesity is a complex chronic metabolic disorder characterized by abnormalities in lipid metabolism. Obesity is not only associated with various chronic diseases but also has negative effects on physiological functions such as the cardiovascular, endocrine and immune systems. As a global health problem, the incidence and prevalence of obesity have increased significantly in recent years. Therefore, understanding assessment methods and measurement indicators for obesity is critical for early screening and effective disease control. Current methods for measuring obesity in adult include density calculation, anthropometric measurements, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, computerized imaging, etc. Measurement indicators mainly include weight, hip circumference, waist circumference, neck circumference, skinfold thickness, etc. This paper provides a comprehensive review of the literature to date, summarizes and analyzes various assessment methods and measurement indicators for adult obesity, and provides insights and guidance for the innovation of obesity assessment indicators.

Energy Metabolism in Residents in the Low- and Moderate Altitude Regions of Central Asia with MAFLD and Type 2 Diabetes Mellitus

The knowledge about the features of energy metabolism in MAFLD in the population living at different climatic and geographic heights is lacking. The goal of this study is to explore the biochemical parameters of blood and erythrocyte energy consumption in patients with MAFLD with and without DM2 living in the low- and moderate-altitude regions of Central Asia. Our study was carried out on patients living in low-altitude mountains: Bishkek, altitude=750-800 m; n=67 (MAFLD with DM 2: n=24; MAFLD without DM2: n=25; control: n=18), and At-Bashy District, Naryn Region, altitude=2046-2300 m; n=58 (MAFLD with DM2: n=28; MAFLD without DM2: n=18; control: n=12). Non-alcoholic fatty liver disease was diagnosed according to history, laboratory tests, liver ultrasound, and exclusion of other liver diseases. The level of liver fibrosis was determined using the FIB-4 score. Blood adenosine 5'-triphosphate (ATP) was determined using the CellTiter-Glo method. Healthy residents living in moderate altitudes have significantly higher levels of cytosolic ATP in their blood (p+≤+0.05) than residents living in low mountains. MAFLD is characterized by an increase in the level of ATP concentration in their blood. ATP concentration decreased significantly in patients with MAFLD with DM2 living in moderate-altitude in comparison to those living in low-altitude mountains. The results suggest that chronic altitude hypoxia leads to a breakdown in adaptive mechanisms of energy metabolism of ATP in patients with MAFLD with type 2 DM.

[Body composition models based on anthropometry, systematic literature review]

Introduction

The body composition determination is carried out through measurement methods that require the use of specialized equipment that is difficult to acquire and manipulate. Therefore, different authors have developed mathematical models for its calculation. The target of this review was to analyze the work carried out on mathematical models of body composition variables from different anthropometric measurements, answering the following questions: what is the corporal variable that the model predicts?, what are the input variables for model development?, how is the patients typification in each model?, what data analysis method has been used?, and how has been the model evaluated? The search was limited to journals found in repositories in the areas of Medicine, Nursing, Biochemistry, Biology, Health, Pharmacology, Immunology, Engineering, and Mathematics. Four hundred and twenty-four articles were found, which were reduced to 30 by applying the systematic literature review process. The analyzed studies are oriented to the prediction of variables related to body fat mass. The evaluation results found for fat-free mass, fat mass and metabolic rate differ according to the comparison technique and the body segments analyzed. The evaluation is mainly based on the intraclass correlation, the Pearson correlation and the coefficient of determination (r2), and they present a good correlation for the population under study.

Prediction of body fat percentage: Development and validation of new anthropometric equations

INTRODUCTION

The aim of this study was to test the validity of existing equations, retrieved from the literature, in the Algerian adult population. To develop, and validate, new predictive equations for body fat percentage (%BF) using simple and easy-to-measure anthropometric parameters.

METHODS

This is a cross-sectional study including 877 Algerian adults who underwent a body composition assessment by the direct segmental multi-frequency bioelectrical impedance technique (Inbody-770). Participants were randomly divided into two groups: the development group (n = 577) and the validation group (n = 300). To develop the equations, multiple linear regression models were analyzed. The predictive performance of the developed equations was compared with the direct technique. The following validation tests were used: Student's t-test for paired samples, correlation, and Bland-Altman diagram. Diagnostic accuracy has also been assessed.

RESULTS

Four existing equations were tested, and all showed statically significant bias. Four new equations were developed; all had satisfactory predictive performance, with a correlation coefficient ranging from 0.72 to 0.94 in men and 0.87 to 0.93 in women. The best-fitting equation was based on body mass index, waist-to-hip ratio, and chest circumference. The diagnostic accuracy of this equation was 96.7% in men and 95.3% in women.

CONCLUSION

The newly developed equations based on anthropometric parameters can serve as a simple tool for the accurate prediction of BF% in adult subjects, at both individual and epidemiological levels.

A new monitoring system for nutritional status assessment in children at home

Regular monitoring of children's nutritional status is essential to prevent micronutrient deficiencies, nutritional status abnormalities as stunting, wasting, overweight and obesity. Nutritional status assessment is usually performed by paediatricians by using anthropometry (body mass index, weight to height indices) and/or by body fat-mass measurement (bioimpedance analysis, dual-energy x-ray absorptiometry, computer tomography, etc.). Parents are also interested in but usually fail to evaluate their child's nutritional status. To help the sufficient collaboration between the physician and parents a new nutritional status monitoring method is developed for families. The new monitoring system was developed under a paediatrician's supervision by considering national and international recommendations, references as well as the anthropometric measurement possibilities at home. The model requires age, sex, body mass, height, waist circumference and hand circumference as predictor (input) variables of nutritional status, while (1) the centile values of the measured body dimensions, (2) body fat percentage and the centile of body fat percentage, (3) the nutritional status category (undernutrition, normal nutritional status, overfat/obese) can be predicted (outcome variables) by the new method. The predictive accuracy of the model for nutritional status category was 94.88% in boys and 98.66% in girls. The new model was developed for nutritional status assessment in school-aged children and will be incorporated in the healthy lifestyle module of 'Teenage Survival Guide' educational package to be developed by the Health Promotion and Education Research Team, Hungarian Academy of Sciences, Hungary. The new monitoring system could help the families to identify the early signs of malnutrition in children. Nutritional status assessment in children at home is suggested twice a year, and in case of suspicious nutritional status abnormality it is recommended to visit the general practitioner.

Criterion-Related Validity of Field-Based Methods and Equations for Body Composition Estimation in Adults: A Systematic Review

PURPOSE OF REVIEW

Overweight and obesity are associated to health prognosis. Therefore, body composition assessment is an important health outcome, especially in adult population. We analyzed the criterion-related validity of existing field-based methods and equations for body composition estimation in adults aged 19-64 years.

RECENT FINDINGS

One hundred studies met inclusion criteria. The field-based methods, waist circumference (WC), body adiposity index (BAI), and body mass index (BMI) are valid to indicate body adiposity. Likewise, several equations, including the classical Durnin/Womersley equation, Jackson/Pollock equation (males), and Jackson, Pollock, and Ward equation (females), are valid to estimate total body fat mass or body fat percentage. Anthropometric field methods can provide a simple, quick, and easy informative indicators of adiposity in adults. Classical equations, such as Durnin/Womersley equation, Jackson/Pollock equation, and Jackson, Pollock, and Ward equation, are still valid to estimate total body fat mass or body fat percentage in adult population. When choosing estimation equations, specific population characteristics, such as age, weight status, or race ethnicity, should be taken into account. (Trial Registration: Registered on PROSPERO (CRD42020194272)).

Proposal of a Mathematical Model to Monitor Body Mass over Time in Subjects on a Diet

Nowadays, slimming diet methodology works within a reduction of body mass using a decrease of dietary energy intake. However, there is no suitable method for understanding the dynamic process of body mass metabolic transformation over time. In the present paper, we have developed a biomathematic model to explain the temporal trend of body mass and its variations of people who have undergone a change in their diet using the solving equation of the model. Data relating to sex, age, body mass, and BMI were collected, and the compartmental model used to interpret the body mass trends was constructed by assuming that the mass results from the sum of the metabolic processes: catabolic, anabolic, distributive. The validation of the model was carried out by variance analysis both on the total and individual data sets. The results confirm that the trend of body mass and its variations over time depends on metabolic rates. These are specific to each individual and characterize the distribution of nutritional molecules in the various body districts and the processes catabolic, anabolic, distributive. Body mass and its variations are justified by the metabolic transformations of the nutritional quantities. This would explain why energetically equal diets can correspond to people of different body mass and that energy-different diets can correspond to people of body mass at all similar.

Neck circumference as a marker of body adiposity in young to middle-aged adults

OBJECTIVE

Neck circumference (NC) is a straightforward method for quantifying upper body adiposity without the limitations that other indices can have. Thus, this study aimed to analyze the relationship between NC, overall (body mass index [BMI]) and central obesity (waist circumference [WC]), and percentage of body fat (BF%) in men and women.

METHODS

The associations with NC quartiles (first quartile: reference group), BMI ≥30 kg/m², WC (>102 cm for men and >88 cm for women), and high BF% (≥21 for men and ≥29 for women) were compared and analyzed by logistic regression models adjusted for demographic characteristics, cardiovascular risk factors, and lean mass.

RESULTS

In 4283 adults (mean age: 44 y, 71.8% of men), the mean NC was higher in men (40.5 cm, range: 32-55 cm) than women (34.5 cm, range: 28.5-46 cm). Among men, the fourth quartile of NC (42.5-55 cm) was positively associated with obesity (multivariable odds ratio [OR]: 2.28, 95% confidence interval [CI]: 1.1-4.48). Among women, the fourth quartile of NC (36.5-46 cm) was associated with increased WC (multivariable OR: 2.98; 95% CI: 1.59-5.60). Progressive increases in the ORs were noticed across the associations between NC quartiles (second to fourth) and high BF% in men and women. The highest ORs were observed for the associations between high BF% and the fourth quartiles of NC in men (multivariable OR: 2.42; 95% CI: 1.49-3.93) and in women (multivariable OR: 29.19; 95% CI: 14.01-60.84).

CONCLUSIONS

The utility of NC as a measurement of obesity in clinical practice was demonstrated in this large sample of young to middle-aged adults. The highest NC values were positively associated with overall obesity in men and central obesity in women. Moreover, NC was closely associated with high BF% in both sexes, particularly in women.

Simple anthropometry-based calculations to monitor body composition in athletes: Scoping review and reference values

BACKGROUND

Kinanthropometry offers to exercise and health professionals a standardized procedure of acquiring surface anatomical measurements that might be used to track changes in body composition.

AIM

To describe simple anthropometric indices to monitor body composition changes in amateur and elite athletes, and to provide reference values during the competition phase.

METHODS

A search of articles indexed in PubMed/MEDLINE, ScienceDirect, Cochrane, and SciELO databases using the string body composition AND (anthropometric OR skinfolds OR circumferences OR girth OR estimation equation) AND "body fat". Inclusion criteria were: quantitative and/or qualitative research published between 2009 and 2020, written in English or Spanish, reporting simple anthropometric indices that included skinfolds, girths, or basic measures in amateur and elite athletes.

RESULTS

A total of 51 studies (Price's index = 66.4%) met all the inclusion criteria and were included in this scoping review. Contrary to the frequent practice, the use of a regression equation might not be accurate to evaluate body composition. To avoid this, anthropometrists should base their analysis on the absolute values of the sum of skinfolds (∑S) and related variables, such as skinfold-corrected girths and lean mass index. While not definitive, because further research is required, the practical recommendations and updated reference values in competition phase provided by this review would contribute to the accurate identification of body composition changes.

CONCLUSIONS

∑S and lean mass index have been shown to be valid for monitoring changes in fat mass and fat-free mass, respectively. More research is needed to derive the lean mass index-specific coefficient for each sports population.

A Comparison of Equation Córdoba for Estimation of Body Fat (ECORE-BF) with Other Prediction Equations

There are multiple formulas for estimating the percentage of body fat (BF%). Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) is one of the most used formulas because of its accuracy and its association with cardiovascular pathologies. Equation Córdoba for Estimation of Body Fat (ECORE-BF) was developed to simplify the calculation of BF% while maintaining a similar level of accuracy. The objective was to compare ECORE-BF in a large sample of Spanish workers using CUN-BAE as a reference. A cross-sectional study was carried out on 196,844 participants. The BF% was estimated using different formulas: relative fat mass (RFM), Palafolls, Deurenberg, and ECORE-BF. The accuracy of the estimation was determined using Lin’s concordance correlation coefficient (CCC) and the Bland–Altman method, using CUN-BAE as the reference method. ECORE-BF reached the highest concordance (CCC = 0.998). It also showed the lowest mean difference (−0.0077) and the tightest agreement limits (−0.9723, 0.9569) in the Bland–Altman test. In both analyses, it remained robust even when separating the analyses by sex, nutritional status, or age. ECORE-BF presented as the most straightforward and most accurate equation for the estimation of BF%, remaining robust regardless of population characteristics.

Development and Cross-Validation of Anthropometric Predictive Equations to Estimate Total Body Fat Percentage in Adult Women in Sri Lanka

Attempts have been made to estimate body fat using anthropometry, and most of them are country-specific. This study was designed to develop and cross-validate anthropometric predictive equations to estimate the total body fat percentage (TBFP) of Sri Lankan adult women. A cross-sectional study was conducted in Galle, Sri Lanka, with two groups: Group A (group for equation development) and Group B (cross-validation group) (n = 175 each) of randomly selected healthy adult women aged 30-60 years. TBFP (%) was quantified with total body DXA (TBFPDXA). Height (m), weight (kg), and skinfold thickness (SFT, mm) at six sites and circumferences (cm) at five sites were measured. In the first step, four anthropometric equations were developed based on the data obtained from multiple regression analyses (TBFPDXA = dependent variable and anthropometric measurements and age = independent variables) with Group A. They were developed on the basis of circumferences (TBFP1), SFTs (TBFP2), circumferences and SFTs (TBFP3), and highly significant circumferences and SFTs (r ≥ 0.6) (TBFP4). In the second step, the newly developed equations were cross-validated using Group B. Three equations (TBFP1, TBFP2, and TBFP4) showed the agreement with cross-validation criteria. There were no differences between TBFPDXA and TBFP estimated by these equations (p > 0.05). They showed higher measurement concordance with TBFPDXA; correlation between measured TBFP with DXA and estimated with TBFP1, TBFP2, and TBFP4, respectively, was 0.80 (R 2 = 0.65, SEE = 3.10), 0.83 (R 2 = 0.69, SEE = 2.93), and 0.84 (R 2 = 0.72, SEE = 2.78). Three anthropometric measurements based on predictive equations were developed and cross-validated to satisfactorily estimate the TBFP in adult women.