Human Prenatal Investment Affected by Maternal Age and Parity

This paper investigates the effects of mother's age and parity on the prenatal allocation of resources in sons and daughters using a sample of 6994 in 20- to 34-year-old mothers from Granada (Spain). This study tests the Trivers–Willard allocation model, which predicts that, depending on the mother's condition, there can be a bias from 50/50 expected investment in the sexes. The results show that mothers of 25–29 age class produce relatively heavier sons compared to younger mothers, suggesting a bias in the allocation of resources before birth favoring neonate boys. This extra investment in boys appears to be related more to the mother's age than to her parity. Offspring of multiparous mothers had shorter gestation length, but multiparous mothers of the 25–29 age class had boys with a longer gestation than the younger ones. The 25–29 age class mothers are in the peak of fertility and they are presumably in better condition than the other mothers in the study sample. The results suggest that Granada women performed a sex-biased prenatal investment favoring sons by prolonging the gestation period. An index of boys' extra birth weight is proposed as a suitable variable to measure the maternal prenatal investment.     

Blood Pressure in Adolescence and Early Adulthood Related to Obesity and Birth Size

Objective: Obesity is an established risk factor for higher systolic (SBP) and diastolic (DBP) blood pressure in adolescence and early adulthood, but birth size may also have a role. We analyzed the effects of adolescent and adult obesity and birth size on BP in the young adult. Research Methods and Procedures: In a prospective longitudinal study, anthropometric measurements were obtained at birth on 67 boys and 67 girls bom in Boston. Their body mass indices (BMI) and BP were recorded 17 years and 30 years later. Results: For women, adolescent and early adult obesity appeared to be the stronger determinants of higher BP, although smaller head and chest circumferences at birth may also be related. We found some evidence of birth (ponderal index [PI] and head circumference) anthropometric influences on age 17 BP levels in boys. By age 30, body mass variables were the dominant predictors of male BP levels. Female BMI at age 17 was positively correlated with birth adiposity (PI), but BMI at 30 was related only to age 17 BMI. Similarly, male BMI at 17 years was higher for those who weighed more at birth, but BMI at 30 years was again related only to age 17 BMI. Discussion: We conclude that adult weight and weight gain are the major determinants of adult BP.     

Familial transmission of eating behaviors in preschool-aged children

To examine weight-related differences in eating behaviors and nutrition of preschool-aged children, the influence of maternal eating behavior on the child's eating behavior, and sex-related differences in the transmission of eating behaviors. A total of 142 mothers of children aged 3-6 years participated. Maternal and child's eating behaviors as well as child's food consumption were assessed using questionnaires completed by mothers. Maternal BMI and child's standardized BMI (BMI-SDS) were also calculated. More than half of the mothers were obese. Multiple regression analysis was used to predict eating behavior of the children by mothers' variables. Overweight children scored higher in external eating, food responsiveness, and speed of eating than normal-weight children, whereas children of overweight mothers showed higher amounts of emotional eating than children of normal-weight mothers. Maternal emotional eating (R(2) = 0.19, P < 0.001) and mother's BMI (R(2) = 0.07, P < 0.05) positively predicted emotional eating of sons. Maternal emotional eating (R(2) = 0.19, P < 0.01) completely mediated the relation between mother's BMI and emotional eating of sons. For mother-daughter dyads, no such relation was found. The tested model shows sex-related differences in the transmission of maternal eating behavior which is discussed as being related to the development and maintenance of obesity.     

Age and Sex-Specific Relationships between Phthalate Exposures and Obesity in Chinese Children at Puberty

Objective

To examine the age and sex-specific associations of urine levels of six mono-phthalates with body size and fat distribution in Chinese children at puberty.

Materials and Methods

Four hundred and ninety-three school-aged children (247 boys, 246 girls) were recruited. Obesity related anthropometric indices were measured and body fat proportion (BF%) was calculated. Spot urine samples were collected and phthalate monoesters were detected by an API 2000 electrospray triple quadrupole mass spectrometer (ESI-MS/MS). Associations between phthalate exposure and overweight/obesity measures and their trends were examined by multiple linear regression and Logistic regression analyses, respectively.

Results

Di-2-ethylhexyl phthalate (DEHP) metabolites and monobutyl phthalate (MBP) were found to be the most detectable chemicals. In 8–10 years (yrs) group, concentrations of MEHP and MBP were significantly higher in girls than those in boys. However, concentrations of all phthalate monoesters, except for MEP and MEHP, in 11–13 yrs boys were significantly higher than those in girls. After adjusting for confounders including puberty onset, urinary concentrations of MBP and sum of low molecular-weight phthalate metabolites (∑LMP) were positively associated with boys'' obesity in a concentration-effect manner, while concentrations of MEHP, MEHHP and sum of DEHP metabolites (∑MEHP) were negatively associated with girls'' obesity. Associations between phthalate exposure levels and BMI z-score changes were age- and sex-specific in school-age children.

Conclusion

There are age and sex-specific concentration-effect associations between phthalate exposure and fat distribution in Chinese children. Urinary phthalate levels in 11–13 yrs boys were about 30 percent higher than those in girls, and ∑MEHP levels in younger boys (<10 yrs) were significantly higher than those in elder boys (>10 yrs). Associations were positive for MBP and ∑LMP with both BMI z-score and fat distribution in boys >10 years of age, and negative for ∑MEHP with fat distribution in girls <10 years of age.     

Age at Puberty and the Emerging Obesity Epidemic

Background

Recent studies have shown that puberty starts at younger ages than previously. It has been hypothesized that the increasing prevalence of childhood obesity is contributing to this trend. The purpose of this study was to analyze the association between prepubertal body mass index (BMI) and pubertal timing, as assessed by age at onset of pubertal growth spurt (OGS) and at peak height velocity (PHV), and the secular trend of pubertal timing given the prepubertal BMI.

Methodology/Principal Findings

Annual measurements of height and weight were available in all children born from 1930 to 1969 who attended primary school in the Copenhagen municipality; 156,835 children fulfilled the criteria for determining age at OGS and PHV. The effect of prepubertal BMI at age seven on these markers of pubertal development within and between birth cohorts was analyzed. BMI at seven years was significantly inversely associated with age at OGS and PHV. Dividing the children into five levels of prepubertal BMI, we found a similar secular trend toward earlier maturation in all BMI groups.

Conclusion/Significance

The heavier both boys and girls were at age seven, the earlier they entered puberty. Irrespective of level of BMI at age seven, there was a downward trend in the age at attaining puberty in both boys and girls, which suggests that the obesity epidemic is not solely responsible for the trend.     

Relationship between early puberty and the risk of hypertension/overweight at age 50: Evidence for a modified Barker hypothesis among Polish youth

The objective of this paper is to evaluate: (a) the association between BMI in childhood and adolescence and BMI at age 50, and (b) the association between timing of maturation at puberty and BMI at age 50 and the occurrence of high blood pressure. We explore whether differences in somatic and physiological factors observed among children with early or late onset of puberty indicates that this period of life could be critical for appearance of some CVD risk factors later in the life cycle. Our data include 135 males and 148 females, born in 1953, participants in the Wroc?aw Longitudinal Study. Data pertaining to their growth and several indices of sexual and skeletal maturation were collected yearly between age 8 and 18. Subsequently, their anthropometric traits were measured and cardiovascular health status was assessed at age 50. We find that BMI at distinct stages in the life cycle were positively correlated. Also BMI at 50 were positively associated with blood pressure at 50. Moreover, earlier maturation at puberty is associated with higher values of BMI at age 50. We also find that earlier pubertal maturation is an independent factor that influences the appearance of high blood pressure in adulthood.     

Family resemblance for anthropometric traits II. Assessment of maternal occupational and age effects

The present study was based on a cross-sectional sample of 1326 subjects (197 fathers, 466 mothers, 307 sons and 356 daughters) belonging to 488 nuclear families from the province of Biscay (Basque Country, Spain), with the purpose of estimating the degree of familial resemblance, for several anthropometric traits, by analysing the correlation coefficients between parent-offspring pairs. Height, weight, biacromial and bicrystal breadths, humerus and femur biepicondylar breadths, arm, waist and hip circumferences, biceps, triceps, subscapular, suprailiac, abdominal, thigh and calf skinfolds were taken from each individual. BMI, WHR and the sum of the seven skinfolds was computed. The mother's occupation and the age of offspring were taken into account, since the combination of all these factors might have an effect on familial resemblance. The mothers were classified into housewife (HM) and working mothers (WM). The offspring were divided into prepuberal, puberal and postpuberal subgroups. Standardised residuals were used to compute father-offspring (FO) and mother-offspring (MO) relations through correlation coefficients computed by maximum likelihood. The results confirm the influence of age on the correlations, since FO correlations revealed an increasing trend in HM's children for weight and another six variables as they grew older. On the other hand, the weight change tends to decrease with age in FO correlations within the WM group. Depending on mother's occupation and children's age, the global trend in the sample results in higher correlations in the second group (WM) than in the first one (HM) for the whole age range, but specially in FO correlations before puberty, where four variables (weight, bicrystal breadth, triceps and subscapular skinfolds) yield statistically significant differences.     

Childhood overweight in the United States: A quantile regression approach

The prevalence of overweight children in the United States has increased dramatically over the past two decades, and is creating well-known public health problems. Moreover, there is also evidence that children who are not overweight are becoming heavier. We use quantile regression models along with standard ordinary least squares (OLS) models to explore the correlates of childhood weight status and overweight as measured by the Body Mass Index (BMI). This approach allows the effects of covariates to vary depending on where in the BMI distribution a child is located. Our results indicate that OLS masks some of the important correlates of child BMI at the upper and lower tails of the weight distribution. For example, mother's education has no effect on black children, but is associated with improvements in BMI for overweight white boys and underweight white girls. Conversely, mother's cognitive aptitude has no effect on white boys, but is associated with BMI improvements for underweight black children and overweight white girls. Further, we find that underweight white children and black girls experience similar improvements in BMI as they get older, but that for black boys there is little if any association between age and BMI anywhere in the BMI distribution.     

Comparison of running performances and prevalence of overweight and obesity in Hungarian and Ukrainian adolescents

The 20-m shuttle run (20-mSRT) is a widely used field test to estimate peak oxygen consumption (VO2peak) and thus to assess aerobic fitness of adolescents (11). The purpose of this study was to analyse differences in basic anthropometric measurements (stature, body mass, percent body fat, BMI) and in aerobic fitness of Hungarian and Ukrainian adolescent boys and girls. We examined gender differences in maximal speed (km h-1), in peak VO2 (mL kg-1 min-1) and maximal heart rate (HRmax min-1). Two hundred ninety-two Ukrainian (mean age=16.5±0.5) and 374 (mean age=16.5±0.5) Hungarian adolescents volunteered to participate in this study. Differences were analysed using factorial analysis of the variance (ANOVA) and Student's t-test. Statistical significance was set at p<0.05. Hungarian boys and girls were significantly taller, heavier and had higher percent body fat than their Ukrainian counterparts. Altogether 10% of Hungarians and 7% of Ukrainians were classified overweight or obese according to Cole's BMI classification (4). VO2peak of Ukrainians (mean=49.44±5.29 mL kg-1 min-1) were significantly higher than that of Hungarians (mean=41.93±8.40 mL kg-1 min-1). Maximal heart rate also differed significantly (Ukrainians mean=201.12±8.43 min-1 vs. Hungarians mean=185.38±18.38 min-1).In conclusion, aerobic fitness of the Ukrainian adolescents was significantly higher than that of the Hungarians independently of BMI or gender.     

Reproducibility of anthropometric measurements in children: a longitudinal study

The purpose of this study was to establish the reproducibility of a series of anthropometric measures performed twice during one week during a three year period in boys and girls. The subjects of this investigation were 39 children (21 boys and 18 girls), 9-10 year of age at the beginning of the study. Children were measured three times with one year interval. Children were classified by Tanner stage 1-2 during the first measurements, stage 1-3 during the second measurements and stage 1-4 during the third measurements. Body height and weight were measured and BMI calculated. All anthropometric parameters were measured according to the protocol recommended by the International Society for the Advancement of Kinanthropometry (Norton & Olds 1996). Nine skinfolds, 13 girths, eight lengths and eight breadths/lengths were measured. The reproducibility of body height (r = 0.995-0.999), body weight (r = 0.990-0.999) and BMI (r = 0.969-0.999) was very high in boys and girls. The intraclass correlations (ICC), technical errors (TE) and coefficients of variation (CV) were quite different depending on the measurement site of the skinfold thickness. It was surprising that the ICCs were highest and TEs and CVs were lowest during the second year of the measurement. The computed ICC was high, and TE and CV values were quite similar and relatively low in girth, length and breadth/length measurements. It was concluded that the reproducibility of girths, lengths and breadths/lengths in children is very high and the reproducibility of skinfolds is high. Specifically, the reproducibility is very high immediately before puberty in boys and girls.     

Serum leptin concentration and its effect on puberty in Naqu Tibetan adolescents

This study aimed to clarify the regularity of leptin in Naqu Tibetan adolescents. This study investigated the concentration of fasting serum leptin and clarified its relationship between BMI and other indices. Healthy Naqu Tibetan adolescents aged 12-18 were investigated randomly in the study. They were divided into seven groups (each year as one group, 12 boys and 12 girls in each group); serum concentrations of leptin, estradiol, testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were analyzed. The height and body weight of the 168 healthy Naqu Tibetan adolescents were also assessed. The leptin level in boys decreased with age but increased in girls; in boys and girls they both differed between groups (p<0.05). In boys, the leptin level was inversely correlated with body mass index (BMI), FSH, and T (p<0.05), while in girls, it was positively related to BMI, FSH, LH, and E2 (p<0.01).These findings suggested that during puberty the serum leptin concentration increased with age in girls while it decreased in boys; in the same age group, the leptin level in girls was significantly higher than in boys. Leptin may have some relationship with puberty in Tibetan adolescents.     

Tracing the response of subcutaneous fat accumulation in two generations of males

The present study included 414 adolescent boys aged 11-17 years and their fathers who volunteered as subjects. All the subjects belonged to Punjabi speaking Khatri, an endogamous urban population residing in Delhi, India. A set of five skinfold thicknesses: biceps, triceps, subscapular, suprailiac and medial calf along with body weight and stature were taken on all the subjects to report the pattern of subcutaneous fat distribution and responsiveness of different skinfold sites to fat deposition with variation in total body fat content. It has been noticed that 16- and 17-year-old sons assumed the pattern of subcutaneous fat distribution of their fathers, which was in favour of trunkal fat. Responsiveness of the five skinfold sites towards deposition of fat varied from site to site in various age groups with suprailiac skinfold sites found to be the most responsive followed by subscapular site. The sensitivity of skinfold sites to fat deposition with increase in weight was found to be greater in middle aged men (fathers) than growing boys (adolescent sons).     

Offspring Grazing and Suckling Rates in a Sexually Dimorphic Ungulate with Biased Maternal Investment (Ammotragus lervia)

An analysis of resource gain is provided for Ammotragus calves during their first year of age. Both grazing and suckling rates are analysed and potential effects caused by age, sex, mother's rank and weaning period studied. During their first day of life, calves devote their time mainly to suckling, grazing starting at the second week of age and exceeding suckling rate from the fourth week onwards. When suckling rate reaches a significant decrease (at 2 mo), male calves show a significantly higher grazing rate than female calves, suggesting a higher energetic demand for males at this age. When calves are 1 mo old, sons of high-ranking mothers devote less time grazing than those of low-ranking ones, which is in accordance with the higher maternal investment they receive. Grazing rate shows distinctive values for the different weaning periods distinguished in this species, but the resumption of mothers' sexual activity, when a mother–offspring conflict occurs, does not affect grazing behaviour. These results are consistent with the biased maternal investment recently found in the same study population but focusing on another aspect, i.e. grazing behaviour, which is determined by calves' own decisions.     

Gender Differences in Associations of Eating Pathology between Mothers and Their Adolescent Offspring

Objective: To study the association of eating pathology between mothers and their adolescent offspring in a population sample. Research Methods and Procedures: The participants were 481 women (mean age, 47 ± SD 5 years; BMI, 25 ± 4 kg/m²) and their 481 adolescent children 16 to 17 years old (BMI, 21 ± 3 kg/m²) of the Stockholm Weight Development Study. Assessment methods were the Three‐Factor Eating Questionnaire Revised 18 and the Eating Disorder Inventory 2. Results: A higher body weight was most related to cognitive restraint for adolescents and to emotional eating for adult women. A mother‐daughter link could be identified for eating pathology, with the strongest link found for emotional eating. No mother‐son link could be identified. Age subgroup analyses revealed a stronger mother‐daughter link for body attitudes in younger mothers and for cognitive restraint in older mothers. Discussion: Gender differences revealed that eating pathology was shared by mothers and daughters but not by mothers and sons. A psychological strategy such as eating as a response to negative emotions was most interrelated between mothers and daughters. Younger mothers shared more attitudes toward the body with their daughters, whereas older mothers shared more restrictive eating behaviors with their daughters. The mother‐daughter links found may be due to gender‐specific genetic and psychological family transmission and gender‐specific environmental influences. The sons’ eating behaviors seem to be more independent and would be formed by other factors than for the girls.     

Differential expenditure of maternal resources in Antarctic fur seals, Arctocephalus gazella, at Heard Island, southern Indian Ocean

Maternal expenditure in lactating Antarctic fur seals (Arctocephalusgazella) was studied at Heard Island in the 1987 to 1988 summer/autumn.The mean birth mass, growth rate, and mass at 60 days of sonswere significantly greater than those of daughters. Maternalforaging trips lasted on average 5.9 days, and attendance boutslasted 1.5 days. Over the course of this study, foraging tripduration increased from 5.0 to 7.0 days, and attendance durationdeclined from 2.0 to 1.5 days. Pups lost 3.2% of their bodymass/day while their mothers foraged at sea, but gained massrapidly during periods of maternal attendance. Sons gained significantlymore body mass (1.9 kg) compared with daughters (1.3 kg) duringmaternal attendance, suggesting that sons consume more milk.Sex differences in mass gain were unrelated to pup age or bodymass. During 2-day maternal attendance bouts, sons gained mostof their mass (71%) during the first day, and daughters increasedmass at almost the same rate each day. The increase in massby sons during maternal attendance was significantly positivelyrelated to both the duration of their mothers' preceding andsubsequent foraging trips. In contrast, mass gained by daughterswas positively related to the duration of their mothers' attendance.Mass at 60 days age was negatively related to birth date insons, and positively related to birth mass in daughters. Thesedata indicate that (1) greater maternal resources are expendedon sons than on daughters, (2) sons receive greater maternalresources because they are male, and not because of their greaterbirth mass and body size, (3) different factors appear to beimportant in determining high postnatal growth in sons and daughters,and (4) demand for resources by sons can influence maternalbehavior and ultimately the level of resources received.     

Age-dependent changes in body size of Greek boys from 1982 to 2002

Objective: The prevalence of childhood obesity has been rising during the past decades in many parts of the world, including Greece. The dispersion of these trends across age, however, is less clear. The aim of this study was to examine the relationship between age and 20‐year changes in anthropometric characteristics of Greek boys. Research Methods and Procedures: A total of 204 and 106 boys 9 years old, 163 and 274 boys 12 years old, and 161 and 240 boys 15 years old were randomly recruited in 1982 and 2002, respectively, throughout the county of Iraklio, Crete, Greece. Height, weight, and BMI were measured. Results: Contemporary 9 and 12 year olds were taller than their peers in 1982 (+2.9% and +1.2%, respectively; p < 0.005), but this was not the case for 15 year olds (?0.8%; p = 0.083). Body weight and BMI were higher now than in the 1980s, and this held true for all age groups (p < 0.001). Increases in weight also showed a decline with advancing age (+17.4%, +13.9%, and +4.0% for 9, 12, and 15 year olds, respectively), whereas BMI changes were similar for those 9 and 12 years of age (～10.5%), but were almost 2‐fold higher than in 15 year olds (+5.5%). Discussion: Contemporary boys are taller, heavier, and have higher BMI values than their peers in 1982, but the magnitude of these increases gradually declines with advancing age. Rates of increase in BMI, however, seem to have greatly accelerated compared with previous decades.     

Influence of some socio-economic factors on growth and development of the boys in the Tuzla region (Bosnia and Herzegovina)

The impact of certain exogenous factor (socio-economic, ecological) has been investigated with special attention paid to the parents' living standard, and number of family members on some anthropometric parameters like: body height, body mass, chest circumference, upper leg circumference, upper arm circumference, sitting height, arm length, leg length, pelvis width, shoulders width, lenght of head and with of head on the sample of 698 boys aged 11 to 16 (17) years in the Tuzla region (the northeastern Bosnia, Western Balkan peninsula). Anthropometric measurements have been carried out using methodology proposed by the International Biological program (IBP). The results of these investigations have shown that there is a certain impact of the socio-economic conditions on the growth and development of boys. Children from families that have better living standard are, as a rule, taller, which is indicated by the statistical significant differences (P > 0.01). This trend indicates also value of Body Mass Index (BMI), which is in younger children from the families with lower living standard 16, while in the same category in the children from the families with better living standard it has value 18.5. The real impact of living conditions on the dynamics of development could be the best seen in the period of puberty. The number of children in the family has negative relationship with anthropometric features. Statistically significant differences (P > 0.001) have been detected in numerous analysed features in families with one or two children in comparison with families with three, four, or five children. Therefore, BMI has been significantly lower (16) in children from families with several children, while in the families with one child in the same growth class (11 years) it was significantly higher (17.4). Similar value of BMI (17.9) have children from the families with five children and which are 17 years old. Besides socio-economic conditions, high level of environmental pollution which is typical for Tuzla region for a long time, has also significant impact on the growth and development of children.     

Parent-child correlation for various indices of adiposity in an endogamous Indian population

The study was conducted on 1,042 Punjabi adults and adolescent boys and girls (11-17 years) belonging to middle class families residing in Delhi, India. To study the relative influence of genetic and environmental factors on various fat measures, a set of 7 body measurements namely weight, stature and skinfold thickness at biceps, triceps, subscapular, suprailiac and medial calf measurements was taken on each subject. There was a redistribution of fat away from extremity towards the trunk, a rapid occurring process in males than in females. Increase in body mass index (BMI) with age was more pronounced in females than in males, both at adolescence and adult stage. There was an increase in grand mean thickness (GMT) calculated as mean of all five skinfold thicknesses, in adolescent girls where as in adolescent boys it fluctuated with age. The trunk/extremity ratios reflected a trend in favor of increase in trunk fat, more marked in boys than in girls. The correlations were of low magnitude, however, some skin folds displayed relatively higher value of correlation indicating that these could be determinant of adult obesity.     

Tracking of anthropometric parameters and bioelectrical impedance in pubertal boys and girls

The aim of this study was to investigate the anthropometric parameters and body impedance once per year during four years of the pubertal period in Estonian children. In total, 81 boys and 86 girls aged 10-11 years at the beginning of the study were investigated. Pubertal status was self-assessed by sexual maturation stages according to Tanner and physical activity index (PAI) according to Telama et al.. Body height and weight were measured and body mass index (BMI) calculated. In total, 9 skinfolds, 13 girths, 8 lengths and 8 breadths/lengths were measured according to the protocol of the International Society for the Advancement of Kinanthropometry. Somatotype components were estimated according to the method of Carter and Heath. Body impedance was measured using Multiscan 5000 (Bodystat, UK) and the impedance index (height/impedance) was calculated. The tracking of body height, weight, BMI, skinfolds, girths, lengths, breadth/lengths and body impedance was high (as a rule r> or =0.9). By increasing the time period, the correlation slightly decreased. In contrast, tracking correlations for PAI and Tanner stages were significant but quite low. Increase in mean body height was highest between 12-13 years of age (6.9 cm per year) in boys and in girls between 11-12 years of age (6.3 cm per year). In boys and girls, the peak increase in body weight was between 11 and 12 years of age, 5.7 kg and 5.2 kg, respectively. With the increasing age, body impedance decreased and impedance index increased. In conclusion, our results indicate that during puberty the detailed anthropometric parameters and body impedance tracked highly. However, the tracking of PAI and Tanner stages was significant but relatively low.     

Sexual dimorphism from birth to age 60 in relation to the type of body shape

Sexual dimorphism depends on age. It can be analysed within a population by a comparison of sex-specific body measurements based on cross-sectional samples. We analysed four length measurements, three circumferences, and one skinfold diameter of a representative cross-sectional sample of healthy German subjects aged 0 to 65 years. We here report that sexual dimorphism of these body measurements already is present in newborns. The percentages of anthropometric differences between female and male subjects behave in a specific pattern during growth age from birth up to adolescence. Girls are born smaller on an average, but they have a more accelerated growth than boys. Girls reach the peak of their adolescent growth spurt earlier in their chronological age. This means that their biological age at this time is at least 2 years older than that of boys of the same chronological age. This sex-specifically differential onset of the adolescent growth spurt, and its peak, as well as the differential decrease of growth velocity cause a dramatic change in sexual dimorphism. This change is clearly shown in this cross-sectional study. Except for the subcutaneous fat layer, there is a clear male growth advantage in all of the measurements investigated after the peak of the adolescent growth spurt. The largest differences between the measurements of both sexes in favour of the male sex are reached at young adult age. In the further course of life, the anthropometrical differences between the sexes decrease again. Sexual dimorphism within a population at a defined chronological age is therefore not only the result of a developing sex-specific physique, but also the result of a sex-specific growth velocity during the successive stages of biological development. Interestingly, we found that the sex-specific velocity of physical development, and by this the development of sexual dimorphism, proceeds differently in the tall and slim leptomorphic individuals in comparison to the smaller and more corpulent pyknomorphic individuals.