Body proportion chart for evaluating changes in stature, sitting height and leg length in children and adolescents.

BACKGROUND: Studies by longitudinal sample to evaluate trends in stature, sitting height, leg length and body proportions together in Japanese children are scarce. AIM: Trends in stature, sitting height, leg length and LUR (lower segment and upper segment ratio) were evaluated with a graphical method (Body Proportion Chart). SUBJECTS AND METHODS: Longitudinal data for 520 boys and 306 girls who had 12 consecutive yearly measurements from 6.5-17.5 years of age were used. RESULTS: Estimated growth rates of leg length were greater than those of sitting height in pre-adolescence in both sexes. Leg length was slightly longer in girls than in boys for a short period early in adolescence, but sitting height in girls exceeded that in boys for a longer period. LUR attained peak values between 12.5-13.5 years in girls (LUR = 85.7) and between 13.5-14.5 years in boys (LUR = 89.2). After attaining maximum LUR, leg length was stable, although sitting height continued to increase slightly in both sexes. CONCLUSION: The results highlight the usefulness of the Body Proportion Chart method for identifying changes in body proportions during adolescence.

Relationship of body composition to body-fatness estimation in Japanese university students.

OBJECTIVE: To examine the relationship between self-estimated whole body size and fatness and whole body and regional composition, and the relationship between self-estimated whole body fatness and self-estimated regional fatness in Japanese university students. RESEARCH METHODS AND PROCEDURES: This was a cross-sectional study using Japanese university students (110 men and 79 women). The percentage of body fat, fat mass (FM), and fat-free mass (FFM) were measured by underwater weighing and used as body composition variables. Subcutaneous fat thicknesses were determined at seven sites by ultrasonography to estimate regional body composition, and six circumferences and four breadths to estimate regional size. Relative body size and fatness were self-estimated using a questionnaire. RESULTS: Only women tended to estimate themselves as being fatter than they actually were. Self-estimated body fatness moderately correlated with the percentage of body fat (men, r = 0.41; women, r = 0.40) FM (men, r = 0.50; women, r = 0.51), and body mass index (r = 0.56 for men and 0.56 for women). After adjusting for the percentages of body fat and FM, self-estimated fatness correlated with body mass index (r = 0.31 for men and r = 0.37 for women). Among self-estimated regional fatness, self-estimated abdominal fatness had the strongest correlation with self-estimated whole body fatness in both genders. DISCUSSION: The low correlation between estimated and actual body fatness in both genders indicates that Japanese university students, especially women, inaccurately estimate their percentage of body fat. In fact, both men and women primarily estimate their whole body fatness by body weight relative to height.

Age change of power in weight/height(p) indices used as indicators of adiposity in Japanese.

Data from the Statistical Report on School Health and Hygiene were used to identify the entire process of the power of height p in the weight-for-height index W/H(p). The appropriate power of height p was determined by clarifying the allometric relationship, giving an index of relative weight, which is highly correlated with weight but uncorrelated with height for age. The procedure is equivalent to fitting a straight line on a log-log scale to the tabulated weights by height in different age groups. The p values show directional changes from 5 to 17 years of age in both sexes. The optimal p value is approximately 2 in preschool children but increases gradually to over 3 at 10 years in males and 11 years in females, and then falls back to 2 after puberty. The largest p value occurs 18 months earlier in females than in males, and the pattern is the same in the present samples and American samples. Because there are remarkable changes between 12 to 14 years in females and 14 to 16 years in males, the general weight-for-height indices with the precise power of height are preferable at these ages. A fixed power 3.0 is suggested for children between 3 and 12 years irrespective of sex or race.

Assessment of body composition by using a new chart method.

The body mass index (BMI, weight/height2 ), is commonly used as a simple and valid way of assessing body composition. However, the significance of the BMI is not clear, since body mass is composed of two main components: fat-free mass (FFM) and fat mass (FM), each with different densities. In order to graphically present body composition as a quantitative measure, a chart based on the fat-free mass index (FFMI, FFM/height2 ) and fat mass index (FMI; FM/height2 ), as reported in a previous paper (Hattori, J. Anthropol. Soc. Nippon 99:141-148, 1991), was revised by adding information on both the percentages of body fat (%fat) and the BMI. The benefit of the new chart method is its simplicity which comes from the application of two variables on a two dimensional chart. The chart containing the lines of %fat and the BMI can be of use in detecting multiple aspects of body composition since it provides four pieces of information at the same time: FMI, FFMI, BMI, and %fat. Am. J Hum. Biol. 9:573-578, 1997. © 1997 Wiley-Liss, Inc.

Determination of body volume in normal adults and in patients with cerebral palsy by the sulfur hexafluoride (SF6 ) dilution technique.

This study sought to establish body volume measurement by the sulfur hexafluoride (SF6 ) dilution technique and to assess the body composition of healthy subjects and patients with the complications of cerebral palsy and mental retardation. Sixty-six healthy males and females ranging in age from 18 to 41 years and 10 patients with the complications ranging in age from 23 to 34 years participated in the study. The SF6 dilution method determines absolute body volumes by measuring the SF6 concentration inside a closed chamber containing the subjects. No detectable deviations were indicated between the body volume measured by SF6 and the volume determined by underwater weighing (r = 0.999). Body volume for patients with complications was also successfully assessed by the SF6 technique. All 10 subjects were short, but body composition measures were within normal ranges except for two obese females. Inactivity was suggested as a relevant factor for the excess adiposity. Thus, this new method of measuring body volume offers promising possibilities for future research in body composition, especially for application in clinical practice. © 1994 Wiley-Liss, Inc.

Fat patterning of adolescents: Allometry of fatfolds.

The relationship between fatfold thickness and fat mass of 101 male and 66 female adolescents (10-16 yr) was examined with the allometric equation y = bxa . Body composition was assessed by underwater weighing and 5 fatfolds were measured: triceps, subscapular, suprailiac, abdominal, and thigh. Percent body fat ranged from 4.9% to 56.1%. The log of each fatfold thickness was plotted versus the log of fat mass. All the relationships were linear and exhibited monophasic allometry. All the alpha coefficients (slope of the log-log plots) exhibited positive allometry. The prepubescent male and female alphas were similar and had the same pattern. The pattern contrasted the trunk with the extremity fatfolds. No differences (P > .05) were found between the alphas for the pubescent males. The triceps alpha of the pubescent females was less (P < .05) than the subscapular, suprailiac, and abdominal alphas. The thigh, subscapular, suprailiac, and abdominal alphas were not significantly (P > .05) different. In conclusion, the trunk was the predominant site of subcutaneous fat deposition for prepubescents, while pubescents exhibit a more general pattern of fat distribution. © 1992 Wiley-Liss, Inc.