Bodyfat percentage in girls increased steadily with age and percentile rank of body mass index

A comparison study of portable foot-to-foot bioelectrical impedance scale to measure body fat percentage in Asian adults and children

Objective. To compare the measurements of body fat percentage (BF%) using the foot-to-foot bioelectrical impedance analysis (FTF-BIA) with the direct segmental multifrequency BIA (DSM-BIA). Methods. There were 36 men and 52 women (37.1 ± 14.3 years) with 57% Malays, 30% Chinese, and 13% Indian. For children, there were 45 boys and 26 girls (11.5 ± 2.5 years) with 52% Malay, 15% Chinese, and 33% Indian. Results. Mean height for men was 168.4 cm, 11 cm taller than women. Men were 10 kg heavier than women at 70 kg. BF% in women was 32% and 33% whereas BF% in men was 23% and 25% when measured using FTF-BIA and DSM-BIA, respectively. In children, BF% measured with FTF-BIA and DSM-BIA was 49% and 46%, respectively. The correlations were significant for men (r = 0.92, SEE = 2.80), women (r = 0.91, SEE = 3.31), boys (r = 0.95, SEE = 5.44), and girls (r = 0.96, SEE = 5.27). The BF% in underweight/normal (r = 0.92, SEE = 2.47) and that in overweight/obese adults (r = 0.89, SEE = 3.61) were strongly correlated. The correlations were significant in normal/underweight (r = 0.94, SEE = 3.78) and obese/overweight children (r = 0.83, SEE = 6.49). All ethnic groups showed significant correlation with BF%. Malay adults (r = 0.92, SEE = 3.27) and children (r = 0.94, SEE = 0.88) showed significant mean differences in BF%. Conclusion. The FTF-BIA showed higher accuracy for all normal/underweight and Chinese group with acceptable overestimation in children and underestimation in adults. Caution should be taken when interpreting BF% depending on gender, BMI, and ethnicity.

Relationship between body mass index and body fat in children-Age and gender differences

SUMMARY

When defining obesity body mass index (BMI) has been used as the main criterion. However it indicates only the nutritional status, whereas body fat demonstrates the real body composition picture. This study aimed at analyzing the relationship between nutritional status and adiposity in the population of 2284 Serbian children (1217 boys and 1067 girls). According to BMI subjects were divided into underweight, normal-weight, overweight and obese, and %BF values (based on skinfold thickness measurements) were analyzed with regard to BMI-category, age and gender. Girls showed stronger correlation between BMI and %BF comparing to boys (r = 0.834 vs. 0.577). Differences in %BF between underweight, normal weight and overweight children from different age groups were more obvious in girls, whereas in boys younger than 8 years overlapping in %BF values between different BMI-categories was registered. In normal weight children we found age-related oscillations in %BF values: 8- and 9-year-old boys had lower %BF comparing to 7-year-old boys, which was followed by %BF increasement in 10- and 11-year-old ones; in girls %BF values gradually increased with aging, with significant jumps in 9-, 10- and 11-year-old ones. Thus, adiposity rebound may appear somehow later in boys. In overweight and obese children of both genders %BF continually increased with aging, whereas in underweight children %BF values remained unchanged. Our results pointed to age- and gender-dependent variations of %BF in normal weight and overweight children. We also indicated inconsistency between %BF and BMI especially in boys, and the need for definition of references for %BF.:

High-molecular-weight adiponectin and anthropometric variables among elementary schoolchildren: a population-based cross-sectional study in Japan

Background

Studies about the relationship between high-molecular-weight adiponectin (HMW-adn) and anthropometric variables among population-based elementary schoolchildren have been too limited, especially in Japan, where blood collection is not usually performed in the annual health examination at elementary schools. The objective of the present study was to investigate the relationship between HMW-adn and anthropometric variables (body mass index [BMI], percent body fat [%BF], waist circumference [WC], and waist-to-height ratio [WHtR]) among population-based elementary schoolchildren in Japan.

Methods

Subjects comprised all fourth-grade schoolchildren (9 or 10 years of age) in the town of Ina, Saitama Prefecture, Japan during 2005–2008 (N = 1675). After excluding 21 subjects because of refusal to participate or incomplete data, data from a total of 1654 subjects (846 boys and 808 girls) were analyzed. The height, weight, %BF, and WC of each subject were measured, while blood samples were drawn from the subjects to measure adiponectin levels (HMW-adn and total adiponectin). Childhood obesity was determined according to the age- and sex-specific cut-off points proposed by the International Obesity Task Force. Spearman’s correlation coefficients between adiponectin levels and anthropometric variables were calculated for each sex.

Results

The anthropometric variables were negatively correlated with HMW-adn in both boys and girls. Correlation coefficients of HMW-adn with anthropometric variables in the obesity group were consistently higher than those in the non-obesity group among both boys and girls. In addition, only WHtR was significantly correlated with HMW-adn regardless of sex and physique (obesity or non-obesity); the correlation coefficient was -0.386 among boys and -0.543 among girls in the obesity group, while it was -0.124 among boys and -0.081 among girls in the non-obesity group.

Conclusions

HMW-adn was negatively correlated with anthropometric variables, while the correlation coefficients of HMW-adn with anthropometric variables in the obesity group were consistently higher than those in the non-obesity group. Moreover, only WHtR was significantly associated with HMW-adn regardless of sex and physique. The results of this study suggested that it is useful to monitor WHtR as a surrogate for HMW-adn among elementary school students, especially obese children.

Do the interactions between glucocorticoids and sex hormones regulate the development of the metabolic syndrome?

The metabolic syndrome is basically a maturity-onset disease. Typically, its manifestations begin to flourish years after the initial dietary or environmental aggression began. Since most hormonal, metabolic, or defense responses are practically immediate, the procrastinated response do not seem justified. Only in childhood, the damages of the metabolic syndrome appear with minimal delay. Sex affects the incidence of the metabolic syndrome, but this is more an effect of timing than absolute gender differences, females holding better than males up to menopause, when the differences between sexes tend to disappear. The metabolic syndrome is related to an immune response, countered by a permanent increase in glucocorticoids, which keep the immune system at bay but also induce insulin resistance, alter the lipid metabolism, favor fat deposition, mobilize protein, and decrease androgen synthesis. Androgens limit the operation of glucocorticoids, which is also partly blocked by estrogens, since they decrease inflammation (which enhances glucocorticoid release). These facts suggest that the appearance of the metabolic syndrome symptoms depends on the strength (i.e., levels) of androgens and estrogens. The predominance of glucocorticoids and the full manifestation of the syndrome in men are favored by decreased androgen activity. Low androgens can be found in infancy, maturity, advanced age, or because of their inhibition by glucocorticoids (inflammation, stress, medical treatment). Estrogens decrease inflammation and reduce the glucocorticoid response. Low estrogen (infancy, menopause) again allow the predominance of glucocorticoids and the manifestation of the metabolic syndrome. It is postulated that the equilibrium between sex hormones and glucocorticoids may be a critical element in the timing of the manifestation of metabolic syndrome-related pathologies.

BMI values and other anthropometric and functional measurements as predictors of obesity in a selected group of adolescents

BACKGROUND

Obesity is well known to be a problem all over the world: WHO data report that one billion subjects are overweight and 300 million are obese. Epidemiological data (IOTF) show that prevalence rates are increasing not only in industrialized countries, but also in developing countries, especially as far as the adolescent population is concerned.

AIM OF THE STUDY

To select adolescents at risk of obesity by BMI calculation and by other anthropometric and functional measurements in the Aosta Valley Mountain Region (Northern Italy).

METHODS

532 adolescents were recruited and participated in the study (254 males and 278 females, aged 15.4 +/- 0.7). According to standard methods, the following parameters were measured: weight and height for BMI calculation, four skin folds (mid-triceps,mid-biceps, subscapular and supra-iliac) to compute body fat mass,waist and hip circumferences, systolic (SBP) and diastolic (DBP) blood pressure. Parental weight and height, educational and socio-economic status were requested from the parents using a questionnaire.

RESULTS

Percentages of overweight and obese boys were 20.9% and 4.7% respectively, and percentages of overweight and obese girls were 14.7% and 1.1% respectively (using Cole's cut off point reference standard). Mean body fat mass percentages (males = 19.3 +/- 5.6%, females 23.3 +/- 4.4%) showed males at risk of obesity, as indicated by a higher prevalence rate of overweight and obesity in this gender. Positive correlations (p <0.01) were found between BMI and the following parameters: mid-triceps skinfolds, body fat mass percentage,waist and hip circumferences, but no correlation emerged with WHR; body fat mass positively correlates (p <0.01) with waist and hip circumferences; students' BMI positively correlates with blood pressure (p <0.01),with parental BMI and shows a positive trend towards parental low education and socioeconomic levels.

CONCLUSIONS

Overweight and obesity prevalence rates are higher in males than in females according to literature data; family influences weight condition. The correlations that emerged show that BMI is a good adiposity index also in adolescents, it acts as an indicator of cardiovascular risk condition and is influenced by parental BMI.

An Open Randomized Controlled Study on the Efficacy of Low-Sodium Water Intake Evaluated by Non-Invasive Methods in Patients with Cellulite

Cellulite is the result of complex physiological changes of the subcutaneous fat layer and of microcirculation, clinically manifesting as orange peel skin especially in women and involving thighs, buttocks, and abdomen. An adequate water intake has been suggested to be helpful in controlling the development and worsening of the disease. An open randomized controlled study has been performed to evaluate modification induced by an adequate diet associated to low-sodium or high-sodium water intake on some clinical features of patients affected with mild to moderate cellulite.

Non-invasive instrumental investigations (Bioelectrical Impedance Analysis (BIA), thermography and skin echography) were used before and after dietary treatment. A significant improvement of the disease, in terms of weight loss, cutaneous microcirculation and reduction of subcutaneous fat layer, was observed in the group of patients who underwent low-sodium water intake. An adequate dietary treatment associated to a low-sodium water intake is able to efficiently controll some biological and clinical parameters of mild to moderate cellulite.