Dimorphism In Body Composition Research Articles

Relationship between Body Composition and Gross Motor Coordination in Six-Year-Old Boys and Girls

The aim of this study was to investigate the association between morphological characteristics (body composition and anthropometric data) and gross motor coordination in preschool children (42 boys and 40 girls, aged 6.22 ± 0.43 years, height: 1.22 ± 0.48 m, body mass index: 20.22 ± 2.34 kg/m2, muscle mass: 11.50 ± 2.08 kg, and fat mass: 5.43 ± 4.02 kg). Motor coordination was determined by the obstacle course backward test (OCB), while body composition was measured using the bioelectrical impedance (BIA) method. Sex differences in the OCB test and body morphology were determined by an independent t-test. Multiple linear regression was used to examine whether morphological characteristics could predict OCB scores. Boys were significantly taller, with greater muscle mass, protein mass, and total body water compared to girls (t = 2.01–3.73, p < 0.05). Inversely, mineral mass was greater in girls than in boys (t = 2.98, p = 0.01). No significant sex differences were observed in the results obtained for the OCB test (t = 0.74, p = 0.46). All morphological variables showed trivial-to-weak (r = 0.01–0.15) associations with the OCB results, without reaching statistical significance (p ≤ 0.16). The model of predictor variables did not have a statistically significant effect on the OCB scores in boys and girls (R2 = 0.09, p = 0.91 and R2 = 0.012, p = 0.92, respectively). These results indicate that sex dimorphism in body composition is present at an early age before puberty, while morphological characteristics have a negligible influence on motor coordination in 6-year-old children.

Sexual dimorphism in body composition of children in the North Backa region

Introduction. Anthropometric measurements are widely used in the assessment of growth, nutritional status and body composition in children. The objective of the study was to describe growth and body composition of children using simple anthropometric measures. Material and Methods. The investigation was performed in 13 primary schools in the territory of North Backa during 2017 and at the beginning of 2018. A total of 593 schoolchildren aged 6.50 - 10.49 years (in decimals) were included in the study. The following parameters were measured: height, weight, upper arm circumference and triceps skinfold thickness. These measurements were used to calculate the body mass index, total upper arm area, upper-arm muscle area, upper-arm fat area, and the arm fat mass percentage for each individual. Results. The study results show that children?s growth is almost linear over the first decade of life and the lean body mass increases at similar rates in boys and girls. However, girls show higher percentage of body fat and higher triceps skinfold thickness, while the body mass index is not significantly different. The secular trends in height are slowing down or have already ceased, but the weight generally continues increasing. Conclusion. Although sexual differences in anthropological measures are insignificant, the differences in body composition are evident before puberty.

Humans as a model species for sexual selection research.

Ever since Darwin, questions about humans have driven sexual selection research. While studies of other organisms are often justified as useful for improving understanding of humans, humans themselves can be useful models. Although humans present some drawbacks as model organisms (complicated societies, slow reproduction and strong ethical constraints on experimental options), humans nonetheless offer many advantages (being abundant, accessible and having detailed historical records for some populations). As an additional challenge, humans exhibit a rather puzzling combination of traits. Some traits (pair-bonding, biparental care and modest sexual dimorphism in body size) suggest selection for monogamous mating, while other traits (including sexual dimorphism in body composition and appearance) suggest selection for polygyny. Such puzzles have motivated research on other species, resulting in a rich set of comparative data that provides insights into humans and other species. Recent studies of visual trait dimorphism suggest that human appearance reflects adaptation for multi-level societies, rather than high levels of polygyny. In addition to biological traits, human cultural traits have undergone rapid evolution. Changes in subsistence strategies profoundly affect opportunities for sexual selection. The enormous variability of human behaviour and ecology provides abundant opportunities to test key hypotheses, and poses challenging puzzles for future research.

Influence of birth weight and gender on lipid status and adipose tissue gene expression in lambs.

Intrauterine growth restriction (IUGR) is a risk factor for obesity, particularly when offspring are born into an unrestricted nutritional environment. In this study, we investigated the impact of IUGR and gender on circulating lipids and on expression of adipogenic, lipogenic and adipokine genes in perirenal adipose tissue. Singleton lambs born to overnourished adolescent dams were normal birth weight (N) or IUGR (32% lower birth weight due to placental insufficiency). IUGR lambs exhibited increased fractional growth rates but remained smaller than N lambs at necropsy (d77). At 48 days, fasting plasma triglycerides, non-esterified fatty acids and glycerol were elevated predominantly in IUGR males. Body fat content was independent of prenatal growth but higher in females than in males. In perirenal fat, relative to male lambs, females had larger adipocytes; higher lipoprotein lipase, fatty acid synthase and leptin and lower IGF1, IGF2, IGF1R, IGF2R and hormone-sensitive lipase mRNA expression levels, and all were independent of prenatal growth category; peroxisome proliferator-activated receptor gamma and glycerol-3-phosphate dehydrogenase (G3PDH) mRNA expression were not affected by IUGR or gender. Adiposity indices were inversely related to G3PDH mRNA expression, and for the population as a whole the expression of IGF system genes in perirenal fat was negatively correlated with plasma leptin, fat mass and adipocyte size, and positively correlated with circulating IGF1 levels. Higher plasma lipid levels in IUGR males may predict later adverse metabolic health and obesity, but in early postnatal life gender has the dominant influence on adipose tissue gene expression, reflecting the already established sexual dimorphism in body composition.

A Nontargeted Proteomic Study of the Influence of Androgen Excess on Human Visceral and Subcutaneous Adipose Tissue Proteomes

Sex hormones, particularly androgens, may influence not only adipose tissue distribution but also its functions. We aimed to evaluate if sexual dimorphism in body composition is accompanied by differences in the protein abundance of adipose tissue by applying a nontargeted proteomic approach. This was a case-control study. The setting was an academic hospital. Twenty-one morbidly obese patients, including 7 men, 7 women showing no evidence of androgen excess, and 7 hyperandrogenic women with polycystic ovary syndrome. We obtained subcutaneous (SAT) and visceral (VAT) adipose tissue samples during bariatric surgery. Protein abundance in VAT and SAT was analyzed by 2-dimensional differential gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight coupled to mass spectrometry. Results were validated by RT-PCR. The abundance of 2 spots of peroxiredoxin 6, creatine kinase B-type, 2 spots of selenium-binding protein 1, ruvB-like 2, 4-trimethylaminobutyraldehyde dehydrogenase, and albumin were higher in VAT compared with SAT in women with polycystic ovary syndrome. Men showed a similar pattern, whereas no difference between adipose tissue depots was observed in control women. Other proteins showed differences between VAT and SAT, confirming previous studies, or between the groups of subjects, without interaction between both effects. Several findings were confirmed by RT-PCR. Sexual dimorphism influences the abundance of several proteins in VAT and SAT. The patterns of abundance in adipose tissue depots of several proteins involved in metabolic processes were similar in women with androgen excess and in men, suggesting that androgens influence adipose tissue function.

Sexual dimorphism in body composition across human populations: Associations with climate and proxies for short‐ and long‐term energy supply

Sexual dimorphism in human stature, physique, and adiposity is well established, but the ecological factors that account for its variability remain unknown. This study aimed to describe population variability in body composition dimorphism, and to test whether annual temperature and proxies for population energy supply accounted for this variability. Data on sex-specific anthropometry (weight, stature, triceps, and subscapular skinfolds) and mean annual temperature were collated for 96 nonindustrialized populations. Lean mass and fat mass were calculated. Sexual dimorphism was expressed in sympercents. Sex-averaged skinfolds and stature were used as proxies for short-term and long-term energy supply, respectively. All outcomes showed significant mean dimorphism except body mass index. The magnitude of dimorphism was not randomly distributed across global regions, being lowest in African and Asian populations and greatest in Arctic populations. There was a negative correlation across populations between lean mass dimorphism and adiposity dimorphism, independent of temperature. With decreasing temperature, dimorphism in both lean mass and adiposity increased. Dimorphism increased in fatter but not taller populations, independently of temperature. The inverse correlation between lean mass dimorphism and adiposity dimorphism indicates a sex-trade-off between these two tissue accretion strategies. At colder temperatures, females invest disproportionately more in adiposity, and males disproportionately more in lean mass. Dimorphism also increased in proportion to proxies for short-term but not long-term energy availability. These findings suggest that phenotypic plasticity contributes to variability in body composition dimorphism, and that the occupation of dimorphic niches regarding reproductive energetics may be important.

Effect of puberty on body composition

Here we examine the effect of puberty on components of human body composition, including adiposity (total body fat, percentage body fat and fat distribution), lean body mass and bone mineral content and density. New methods and longitudinal studies have expended our knowledge of these remarkable changes. Human differences in adiposity, fat free mass and bone mass reflect differences in endocrine status (particularly with respect to estrogens, androgens, growth hormone and IGF-1), genetic factors, ethnicity and the environment. During puberty, males gain greater amounts of fat free mass and skeletal mass, whereas females acquire significantly more fat mass. Both genders reach peak bone accretion during the pubertal years, though males develop a greater skeletal mass. Body proportions and fat distribution change during the pubertal years as well, with males assuming a more android body shape and females assuming a more gynecoid shape. Pubertal body composition may predict adult body composition and affects both pubertal timing and future health. Sexual dimorphism exists to a small degree at birth, but striking differences develop during the pubertal years. The development of this dimorphism in body composition is largely regulated by endocrine factors, with critical roles played by growth hormone and gonadal steroids. It is important for clinicians and researchers to know the normal changes in order to address pathologic findings in disease states.

Testicular Expression of Steroidogenic Enzyme Genes Is Related to a Transient Increase in Serum 19-nortestosterone during Neonatal Development in Pigs

Cytochrome P450 aromatase is responsible for the biosynthesis of estrogen. It is also responsible for the endogenous production of 19-nortestosterone (nandrolone), an anabolic androgen unique to pigs. Plasma concentrations of 19-nortestosterone are highest between two and four weeks after birth in male pigs. In the present study, the physiology of 19-nortestosterone was investigated by measuring the mRNA levels of steroidogenic enzymes, estrogen receptors and androgen receptor in the tissues of growing pigs. The expression of aromatase, 17α-hydroxylase and 3β-hydroxysteroid dehydrogenase in the testes of male piglets increased between birth and two weeks of age, and then decreased progressively. Similar developmental expressional patterns were observed for 17α- hydroxylase and 3β-hydroxysteroid dehydrogenase in the ovaries of female piglets, but without significant aromatase expression. The major form of aromatase expressed in the testes of piglets was identified as type I. Expression of estrogen receptor-α and -β and androgen receptor genes was also detected in both testes and ovaries. A transient elevation of androgen receptor mRNA in male piglets at two weeks of age was also observed in testes. Significant expression of the androgen receptor gene, but not of estrogen receptor-α and -β genes, was also demonstrated in adipose tissue and muscle. We conclude that the observed increase in the testicular expression of aromatase in male pigs could account for the production of large amounts of 19-nortestosterone at between two and four weeks of age in males. Androgen receptor and 19-nortestosterone appeared to be important for testicular development and might contribute to sexual dimorphism in body composition and muscle development in juvenile pigs. (Key Words : Cytochrome P450 Aromatase, Pig Testis, 19- Nortestosterone)

Seasonal variation and sex differences in the nutritional status in two local populations of wild Japanese macaques

Seasonal variations and sex differences in the nutritional status in two local populations of wild Japanese macaques (Macaca fuscata fuscata) were examined. It was hypothesized that the ecological condition and/or reproductive strategies of each sex determine the nutritional condition and its seasonal fluctuation in each sex. Morphometric measures such as body mass, thoracic and femoris circumferences, skinfold thickness in four places (triceps, biceps femoris, subscapular, and abdomen), and wet mass of mesenteric and omental fat were used for comparisons between sexes, seasons, and populations. Animals of the Shimane population were larger than those of the Boso population in most morphometric measures, abdominal skinfold, and mesenteric and omental fat mass, suggesting environmental and/or genetic differences in the two populations. Females of both populations had larger skinfolds and mesenteric and omental fat mass than males, indicating that females had more fat than males. Females showed seasonality in most measures, having two peaks of body mass, thoracic and femoris circumferences, abdominal skinfold, and mesenteric and omental fat masses in early spring and late fall. In contrast, males exhibited no clear seasonal variations for most measurements, except for biceps femoris and subscapular skinfolds, which showed peaks in summer. Most morphometric measurements significantly correlated to each other, particularly in females, but most skinfolds had no correlation with other measurements. These findings suggest that sexual dimorphism in body composition and its fluctuation may be affected by the different reproductive strategies of males and females.

Sexual Dimorphism in Body Composition in Brazilian School Children from 1979/80 to 1993/94

Nutritional stress can be seen in several catastrophic events like wars and when socio-economic differences are very important. Nutritional stress can affect growth and development, changing body composition and minimizing sexual dimorphism. Background: The purpose of this study was to evaluate sexual dimorphism in BMI, upper arm circumference (UAC), upper arm fat area (UAFA), and upper arm muscle area (UAMA) in school children from Paulnnia, Sγo Paulo, Brazil between 1979/80 and 1993/94, periods in which the city had good development, low under nutrition rate and positive growth secular trends. Material and methods: BMI, UAC, UAFA and UAMA were calculated for 2098 children (age range 6.5 – 10.5 yr; 540 (310M:230F) in 1979/80 and 1558 (865M:693F) in 1993/94. Sexual dimorphism was measured by relative differences between means with the formula: DS = (50*(x1-x2)) / (x1+ x2) (SD1+ SD2), where: x1= mean for males, x2= mean for females, SD1= standard deviation for males and SD2= standard deviation for females. Results: Sexual dimorphism showed similar BMI, but UAC and UAFA that were higher in boys in the first study became lower in the second one. These changes were more significant in UAFA. UAMA data were similar in both sexes in the first study and became higher in males in the second one. Conclusions: These trends showed a recovery in sexual dimorphism. Girls recovered fat mass and boys got muscle mass in a lower degree.

Sexual dimorphism in the energy content of weight change.

The energy content of weight change is assumed to be sex- and age-neutral at 3,500 kcal/pound or 32.2 MJ/kg. As sexual dimorphism in body composition generally exists in mammals, the primary hypothesis advanced and tested was that the energy content of weight change differs between men and women. The energy content of 129 adult men and 287 women was measured by neutron activation analysis. Cross-sectional energy content prediction models were developed and then evaluated in two longitudinal samples: one that used the same methods in 26 obese women losing weight; and the other a compilation of 18 previously reported weight change-body composition studies. Multiple regression modeling identified weight, sex, age and height as total energy content predictor variables with significant sex x weight (P<0.001) and age x weight (P<0.001) interactions; total model r(2) and s.e.e. were 0.89 and 107.3 MJ, respectively. The model's predictive value was supported in both longitudinal evaluation samples. Model calculations using characteristics of representative adults gaining or losing weight suggested that the energy content of weight change in women (approximately 30.1-32.2 MJ/kg) is near to the classical value of 32.2 MJ/kg and that in men the value is substantially lower, approximately 21.8-23.8 MJ/kg. The predicted energy content of weight change increases by about 10% in older (age approximately 70 y) vs younger (approximately 35 y) men and women. Sexual dimorphism and age-dependency appears to exist in the estimated energy content of weight change and these observations have important clinical and research implications.

Sexual dimorphism in body composition of small mammals

Differences in reproductive roles between the sexes may lead to sexual dimorphism in body composition. Body size and composition of three species of small mammals (bushy-tailed wood rats (Neotoma cinerea Ord), deer mice (Peromyscus maniculatus Wagner), and red-backed voles (Clethrionomys gapperi Vigors)) were analyzed to test the predictions that (i) males will have more muscle mass than females and (ii) females will have more fat than males. Results supported the first prediction but not the second. For all three species, males had more lean dry mass relative to body size than females, but females did not have relatively more fat than males. Muscle mass of males may aid in mate-searching and mate-guarding activities, but fat content may not differ between the sexes because female small mammals depend on increased ingestion rates, rather than fat stores, to support reproduction.

Sexual dimorphism in body composition of small mammals

Sexual dimorphism in body composition of small mammals

Visual cues to female physical attractiveness.

Evolutionary psychology suggests that a woman's sexual attractiveness is based on cues of health and reproductive potential. In recent years, research has focused on the ratio of the width of the waist to the width of the hips (the waist-to-hip ratio (WHR). A low WHR (i.e. a curvaceous body) is believed to correspond to the optimal fat distribution for high fertility, and so this shape should be highly attractive. In this paper we present evidence that weight scaled for height (the body mass index (BMI)) is the primary determinant of sexual attractiveness rather than WHR. BMI is also strongly linked to health and reproductive potential. Furthermore, we show how covariation of apparent BMI and WHR in previous studies led to the overestimation of the importance of WHR in the perception of female attractiveness. Finally, we show how visual cues, such as the perimeter-area ratio (PAR), can provide an accurate and reliable index of an individual's BMI and could be used by an observer to differentiate between potential partners.

Body composition assessment of young tennis players by multi-frequency impedance measurements

Body composition was estimated in 169 young tennis players using the multi-frequency impedance method to predict their fatfree-mass, fat, extra-cellular water, and total body water. Bioelectrical impedances at 1, 5, 10, 50 and 100 kHz were determined. Ratios of impedance at low to high frequencies (Z1/Z100; Z5/Z100) were also used as indicators of body water distribution. This sample is characterized by a greater body mass — fat mass, above all-than other Italian sport participants. Sexual dimorphism in body composition is also evident in this sample. The parameters of body composition, predicted by impedance measurements were compared with parameters obtained through other methods (skinfolds and BMI) on the same subjects. Results varied considerably, in relation to the various equations or different techniques employed. Besides demonstrating the value of multifrequency impedance measurements in the assessment of body composition, our findings indicate the necessity of further methodological research to validate the method under controlled conditions.