Relationship of low lean body mass with body weight increase until one year of age and current lifestyles in Japanese young women

To investigate factors affecting the low lean body mass (LBM) of young women, we focused on the increase in body weight until one year of age and current lifestyles. In 442 young women, the increase in body weight from birth until one year of age, breast-feeding method in infancy, current physique index and body composition, and physique and lifestyles were investigated using a questionnaire. Subjects with an LBM percentile of less than 33.3 (less than 36.8 kg) were classified as having a low LBM (n = 150), and those with a 33.3 or higher LBM percentile as the control (n = 293). Based on body weight changes from birth to days 3 and 7, the subjects were divided into a rapid weight gain group and two non-rapid weight gain groups (groups 1-3). To analyze factors involved in a low LBM, multivariate analysis using a logistic model was employed. The prevalence of a low LBM in the rapid weight gain group was 0.41 times higher than in the others. The prevalence of a low LBM with a low birth weight was 0.58 times higher, indicating that a low birth weight is likely to result in a low LBM. Regarding the lifestyles, the prevalence of a low LBM in subjects with a current breakfasting habit was 0.60 times higher than in those without one. These findings suggest that the thinness of young women characterized by a low LBM is associated with the increase in body weight until one year of age and current lifestyles.     

A method for predicting maximal strength in collegiate women athletes

The purpose of this study was to develop a regression equation capable of accurately predicting a 1 repetition maximum bench press in collegiate women athletes. The findings of this study could benefit future women athletes by providing coaches and trainers with an easy method of determining maximum upper body strength in women athletes. Sixty-five University of Georgia NCAA Division 1 women athletes from 9 different sports were measured prior to the start of their season utilizing 2 repetition tests to fatigue (25 kg: REPS55; 31.8 kg: REPS70) and a 1 repetition maximum (1RM) bench press test in random order. Other independent variables that were used with a submaximal weight to predict 1RM were total body weight, lean body mass (LBM), height, and percent body fat. The variables of REPS70 and LBM were the best predictors of 1RM utilizing Pearson product correlations (r = 0.909, p = 0.000; r = 0.445, p = 0.000) and multiple regression results (R(2) = 0.834, p = 0.000) for this population. The results from this study indicate muscular endurance repetitions using an absolute weight of 31.8 kg in conjunction with LBM can be used to accurately predict 1RM bench press strength in collegiate women athletes.     

Body Compartment and Subcutaneous Adipose Tissue Distribution - Risk Factor Patterns in Obese Subjects

The purpose of this study was to investigate whether upper body obesity and/or visceral obesity are related to cardiovascular risk factors among severely obese subjects, phenomena that have previously been reported in more heterogeneous body weight distri -buttons. 2450 severely obese men and women aged 37 to 59 years, with a body mass index of 39 ± 4.5 kg/m² (mean ± SD) were examined cross-sectionally. Eight cardiovascular risk factors were studied in relation. to the following body composition indicators: four trunk and three limb circumferences, along with weight, height and sagittal trunk diameter. From the latter three measurements lean body mass (LBM, i.e., the non-adipose tissue mass) and the masses of subcutaneous and visceral adipose tissue were estimated by using sex-specific prediction equations previously calibrated by computed tomography. Two risk factor patterns could be distinguished: 1. One body compartment- risk factor pattern in which the subcutaneous adipose tissue (AT) mass and, in particular, the visceral AT mass were positively related to most risk factors while the lean body mass was negatively related to some risk factors. 2. One subcutaneous adipose tissue distribution- risk factor pattern in which the neck circumference was positively and the thigh circumference negatively related to several risk factors. It is concluded that lean body mass (LBM), visceral and subcutaneous adipose tissue masses as well as neck and thigh circumferences, used as indices of subcutaneous adipose tissue distribution, are independently related to cardiovascular risk factors in severely obese men and women.     

Estimation of total water and fatness from weight and height: inaccurate for lean women

Mellits and Cheek have provided a regression equation which predicts total water, and by extension, fat, from weight and height of women. The equation has been used by many researchers as a convenient means to estimate fat when more complicated body composition estimation techniques are not possible. It is an essential component of evidence provide by Frisch for the critical fat hypothesis. The equation has not been validated on another sample, however, and has a large standard error. I test the Mellits and Cheek equation on five samples of young women, two of which show a normal range of heights and weights. The other three are athletic samples composed of lean women. In the normal samples mean fat percent determined by density (from underwater weighing) is closely approximated by the weight and height equation but not in the lean samples. When measured fat is regressed on estimated fat, correlations are low, and standard errors are high, suggesting that the Mellits and Cheek equation predicts poorly the body fat percentage of individual females. In summary, the Mellits and Cheek equation is moderately useful for the prediction of group means for body composition on samples with normal ranges of height and weight. It does not produce acceptable results on groups selected for extreme leanness or obesity. It is not recommended for fat prediction of individuals.     

性发育对女性最大吸氧量的影响

根据是否发生月经，将１１－１３岁女童分为未来潮组及已来潮组，比较两组身高，体重，瘦体重及最大吸氧量的差。结果表明同龄月经来潮组女童身高，体重，瘦体重，ＶＯ２ｍａｘ绝对值，ＶＯ２ｍａｘ／身高及ＶＯ２ｍａｘ／ＨＲｍａｘ均低于已来潮女童，而ＶＯ２ｍａｘ／体重及ＶＯ２ｍａｘ／瘦体重略高于已来潮组女童，产生这种差异的可能原因。     

Race Differences in Accuracy of Self‐Reported Childhood Body Size Among White and Black Women

Objective: To assess the relation of self‐reported current and recalled preadolescent body size to measured BMI (kilograms per meter squared) and interviewer's assessment of body size. Research Methods and Procedures: This was a prospective cohort study of 1890 white and black women who were 9 to 10 years old at time of enrollment and were followed up 10 to 13 years later. At baseline, subjects had their weight and height measured and were asked to indicate their current body size from a series of nine pictograms. A sample of the subjects also had their body size evaluated by interviewers. At the young‐adult follow‐up visit, subjects were asked to recall their body size at 9 and 10 years old and to indicate their current weight, height, body size, and level of concern with weight. Results: Among the women with interviewer assessments, 84% of the white women and 67% of black women recalled a body size that was within one body size of the interviewer's assessment. Independent of weight status in childhood or at follow‐up, black women were 3 times more likely than white women to recall a body figure that was more than one figure leaner than the shape they reported at baseline (odds ratio = 3.5, 95% confidence interval 2.8 to 4.5) or than the interviewer's rating at baseline (odds ratio = 3.4, 95% confidence interval 2.4 to 4.9). Discussion: The results suggest that the use of body figures to recall childhood size are best suited for ranking subjects in terms of BMI. The higher rate of underestimation of size by black women suggests that body figure ratings work best for white women.     

Fat distribution in lean and obese young indian women: A densitometric and anthropometric evaluation

The pattern of fat distribution in lean and obese young Indian women was studied using seven girths and ten skinfold thicknesses. Though the lean and obese subjects differed significantly with respect to their body weight and total body fat content, body girths indicated that the proportion of fat distributed between the extremities and over the trunk region was essentially similar. By comparing skinfold thicknesses, it was observed that the fat women were merely an exaggeration of the fat profile pattern of the lean women. Although the pattern of subcutaneous fat distribution was similar in lean and obese subjects, the rate of fat deposition differed on different parts of the body with increase in total adiposity.     

Breast cancer risk and the interaction between adolescent body size and weight gain in later life: A case-control study

BackgroundWhile the breast cancer risk associated with increasing adult BMI in postmenopausal women can be explained by increases in concentrations of endogenous estrogens the biologic mechanisms behind the inverse association between adolescent BMI and breast cancer risk are still a subject of controversial debate.MethodsWe investigated the association of breast cancer with body size and changes in body size across life time estimated by age-specific BMI Z scores and changes in BMI Z scores from teenage years to middle age in an age-matched population-based case-control study of 2994 Australian women. Logistic regression adjusted for the matching factor age and further potential confounders was used.ResultsAdolescent body leanness in postmenopausal women and excess adult weight gain in all study participants were associated with an increased breast cancer risk with an odds ratio [95% confidence interval] of 1.29 [1.08,1.54] and 1.31 [1.09,1.59], respectively. Interaction analyses restricted to postmenopausal women revealed an increased risk of breast cancer in those who were lean during adolescence and gained excess weight during adulthood (odds ratio [95% confidence interval]: 1.52 [1.19,1.95]) but not in women who were lean during adolescence and did not gain excess weight during adulthood (1.20 [0.97,1.48]) and not in women who were not lean during adolescence and but gained excess weight during adulthood (1.10 [0.95,1.27]) compared to postmenopausal women who were neither lean during adolescence nor gained excess weight.ConclusionIn postmenopausal women adolescent leanness was only associated with increased breast cancer risk when excess weight was gained during adulthood.     

Dynamics of Change in Total and Regional Body Composition After Gastric Bypass in Obese Patients

Little is known on patterns of change over time in body composition, especially lean body mass (LBM), during massive weight loss after Roux‐en‐Y gastric bypass (RYGB) in obese patients. We performed sequential measurements of total and regional body composition in patients after RYGB, and we compared a subsample of patients after surgery to a nonsurgical control group of similar age and body fatness. We used dual‐energy X‐ray absorptiometry (DXA) before and at 3, 6, and 12 months after RYGB in 42 obese women (before surgery: age 39.5 ± 11.6 years; BMI 44.6 ± 6.1 kg/m²; mean ± s.d.) and in 48 control obese women referred for nonsurgical weight management, before weight loss. During 1‐year follow‐up after RYGB, there was a continuous decrease in body weight (?36.0 ± 12.5 kg at 1 year), total fat mass (FM) (?26.0 ± 9.1 kg), as well as in trunk and appendicular FM. In contrast, the decrease in total LBM (?9.8 ± 4.8 kg at 1 year), as well as in trunk and appendicular LBM, plateaued after 3–6 months. Rates of loss in weight, FM, and LBM were highest during the first 3‐month period after RYGB (6.4 ± 1.8, 4.1 ± 1.7, and 2.3 ± 1.2 kg/month, respectively), then decreased continuously for FM but plateaued for LBM. There was no evidence of a decrease in total, trunk, or appendicular LBM in weight‐reduced subjects compared to the control group. In conclusion, follow‐up of these obese women revealed a differential pattern of change in FM and LBM after RYGB. Despite an important loss in LBM, especially during the 3–6 months of initial period, LBM appears to be spared thereafter.     

Exercise and body composition

We assessed changes in body composition in 41 young adults who engaged in various exercise and/or training programs on ad libitum diets. Most of those who gained weight sustained an increase in lean body mass (LBM), and most of those who lost weight lost LBM as well as fat. The change in LBM was directly related to the change in weight, with a regression slope of 0.500. An analysis of published data confirms these findings and, in concert with our data, provides the additional information that the magnitude of the change in body composition in exercising individuals is influenced by body fat content, just as it is for nonexercising individuals.     

Racial Differences in Selection of Ideal Body Size by Adolescent Females

Cultural differences may partially account for the fact that more black women than white women are overweight in the United States. This study measured perceptions of ideal body size among 93 black and 80 white females, 14–17 years old, who were randomly selected from three public high schools in a southeastern state. The subjects' height and weight were measured along with their estimates of their mother's body size, weight control attitudes, and demographic variables . Blacks preferred a significantly larger body sue than whites when asked to select ideal body size (p=0.045). Subjects who estimated their mother's size to be larger, also selected a larger ideal body size (p=.047). Those who perceived themselves as too fat were more likely to skip meals to help control their weight, compared with those who perceived themselves as normal or too thin (p=.003). Approximately 30% of the sample was overweight or obese. There were not significant racial differences in weight or BMI . These results suggest that overweight is more acceptable among black females than among white females and may help explain why more black females are obese .     

Physiological correlates of skating performance in women's and men's ice hockey

The purpose of the current investigation was to identify relationships between physiological off-ice tests and on-ice performance in female and male ice hockey players on a comparable competitive level. Eleven women, 24 ± 3.0 years, and 10 male ice hockey players, 23 ± 2.4 years, were tested for background variables: height, body weight (BW), ice hockey history, and lean body mass (LBM) and peak torque (PT) of the thigh muscles, VO2peak and aerobic performance (Onset of Blood Lactate Accumulation [OBLA], respiratory exchange ratio [RER1]) during an incremental bicycle ergometer test. Four different on-ice tests were used to measure ice skating performance. For women, skating time was positively correlated (p < 0.05) to BW and negatively correlated to LBM%, PT/BW, OBLA, RER 1, and VO2peak (ml O2·kg(-1) BW(-1)·min(-1)) in the Speed test. Acceleration test was positively correlated to BW and negatively correlated to OBLA and RER 1. For men, correlation analysis revealed only 1 significant correlation where skating time was positively correlated to VO2peak (L O2·min(-1)) in the Acceleration test. The male group had significantly higher physiological test values in all variables (absolute and relative to BW) but not in relation to LBM. Selected off-ice tests predict skating performance for women but not for men. The group of women was significantly smaller and had a lower physiological performance than the group of men and were slower in the on-ice performance tests. However, gender differences in off-ice variables were reduced or disappeared when values were related to LBM, indicating a similar capacity of producing strength and aerobic power in female and male hockey players. Skating performance in female hockey players may be improved by increasing thigh muscle strength, oxygen uptake, and relative muscle mass.     

Reliability of self-reported body height and weight of adult Japanese women

The purpose of this study was to validate the self-reported body height and weight of adult Japanese women. The subjects were women, aged 20-42 years, who participated in a survey on eating disorders in women in 1995. Physically measured height and weight data were obtained for 368 (89.8%) of the 469 women who self-reported their height and weight. The report-based heights and weights were compared with the measured values. The correlation coefficients for height and weight were 0.990 and 0.963 (p < 0.0001), respectively. Mean reported height was 0.1 cm shorter and mean reported weight 0.2 kg lighter than the measured values. Shorter women tended to report a taller height than their actual height, and heavier women to report a lower weight than their actual weight. Despite these limitations, the self-reported heights and weights of adult Japanese women were precise and accurate, and their use in epidemiological surveys is considered acceptable.     

Contribution of the lean body mass to insulin resistance in postmenopausal women with visceral obesity: a Monet study

Some insulin-resistant obese postmenopausal (PM) women are characterized by an android body fat distribution type and higher levels of lean body mass (LBM) compared to insulin-sensitive obese PM women. This study investigates the independent contribution of LBM to the detrimental effect of visceral fat (VF) levels on the metabolic profile. One hundred and three PM women (age: 58.0+/-4.9 years) were studied and categorized in four groups on the basis of their VF (higher vs. lower) and lean BMI (LBMI=LBM (kg)/height (m2); higher vs. lower). Measures included: fasting lipids, glucose homeostasis (by euglycemic/hyperinsulinemic clamp technique and 2-h oral glucose tolerance test (OGTT)), C-reactive protein (CRP) levels, fat distribution (by computed tomography (CT) scan), and body composition (by dual-energy X-ray absorptiometry). Women in the higher VF/higher LBMI group had lower glucose disposal and higher plasma insulin levels compared to the other groups. They also had higher plasma CRP levels than the women in the lower VF/lower LBMI group. VF was independently associated with insulin levels, measures of glucose disposal, and CRP levels (P<0.05). LBMI was also independently associated with insulin levels, glucose disposal, and CRP levels (P<0.05). Finally, significant interactions were observed between LBMI and VF levels for insulin levels during the OGTT and measures of glucose disposal (P<0.05). In conclusion, VF and LBMI are both independently associated with alterations in glucose homeostasis and CRP levels. The contribution of VF to insulin resistance seems to be exacerbated by increased LBM in PM women.     

Relationships between body dimensions and resting and working oxygen consumption in boys aged 11 to 18 years

The relationships between VO2 at rest, VO2max and VO2 during submaximal work on a treadmill with body weight, height and lean body mass assessed by densitometry were analyzed annually in 39 boys aged 11 to 18 years. Interindividual differences in VO2 at rest and VO2max during growth depended in the first place on interindividual differences in lean body mass, to a lesser extent on differences in body weight and least on differences in height. Intersubject differences in VO2 during submaximal work were primarily conditioned by differences in body weight, due to the fact that, at a given running speed, energy output depends on body weight. The differences in submaximal VO2 depended to a lesser extent on differences in lean body mass and least on differences in height. The relationships between VO2 increments and increases in body dimensions were somewhat different in 90 boys between the ages of 11 and 15 years: VO2max increments were determined primarily by changes in body weight and height, changes in lean body mass being of secondary importance. Increases in submaximal VO2 were influenced decisively by increments in body weight, followed by increments in lean body mass and least by increments in height. In the equation y = a.xb expressing the relationship of VO2max to body weight and height, the values of b at the ages of 14 and 15 years were 0.87 and 0.88 in relation to body weight, 2.63 and 2.72 in relation to height. These values are significantly higher than the theoretical values of 0.67 for body weight and 2.00 for height. Similar significant differences from these theoretical values were found for all values between the ages of 11 and 15 years.     

Reliability of Multifrequency Bioelectrical Impedance Analysis to Quantify Body Composition in Patients After Musculoskeletal Trauma

BackgroundChanges in body composition, especially loss of lean mass, commonly occur in the orthopedic trauma population due to physical inactivity and inadequate nutrition. The purpose of this study was to assess inter-rater and intra-rater reliability of a portable bioelectrical impedance analysis (BIA) device to measure body composition in an orthopedic trauma population after operative fracture fixation. BIA uses a weak electric current to measure impedance (resistance) in the body and uses this to calculate the components of body composition using extensively studied formulas.MethodsTwenty subjects were enrolled, up to 72 hours after operative fixation of musculoskeletal injuries and underwent body composition measurements by two independent raters. One measurement was obtained by each rater at the time of enrollment and again between 1-4 hours after the initial measurement. Reliability was assessed using intraclass correlation coefficients (ICC) and minimum detectable change (MDC) values were calculated from these results.ResultsInter-rater reliability was excellent with ICC values for body fat mass (BFM), lean body mass (LBM), skeletal muscle mass (SMM), dry lean mass (DLM), and percent body fat (PBF) of 0.993, 0.984, 0.984, 0.979, and 0.986 respectively. Intra-rater reliability was also high for BFM, LBM, SMM, DLM, and PBF, at 0.994, 0.989, 0.990, 0.983, 0.987 (rater 1) and 0.994, 0.988, 0.989, 0.985, 0.989 (rater 2). MDC values were calculated to be 4.05 kg for BFM, 4.10 kg for LBM, 2.45 kg for SMM, 1.21 kg for DLM, and 4.83% for PBF.ConclusionPortable BIA devices are a versatile and attractive option that can reliably be used to assess body composition and changes in lean body mass in the orthopedic trauma population for both research and clinical endeavors. Level of Evidence: III     

Gender- and height-related limits of muscle strength in world weightlifting champions.

To assess factors that limit human muscle strength and growth, we examined the relationship between performance and body dimensions in the world weightlifting champions of 1993-1997. Weight lifted varied almost exactly with height squared (Ht(2.16)), suggesting that muscle mass scaled almost exactly with height cubed (Ht(3.16)) and that muscle cross-sectional area was closely correlated with body height, possibly because height and the numbers of muscle fibers in cross section are determined by a common factor during maturation. Further height limitations of muscle strength were shown by only one male champion >/=183 cm and no female champions >/=175 cm. The ratio of weight lifted to mean body cross-sectional area was approximately constant for body-weight classes 相似文献   

DXA: Can It Be Used as a Criterion Reference for Body Fat Measurements in Children?

Objective: Dual‐energy X‐ray absorptiometry (DXA) is often cited as a criterion method for body composition measurements. We have previously shown that a new DXA software version (Hologic Discovery V12.1) will affect whole‐body bone mineral results for subjects weighing <40 kg. We wished to reanalyze pediatric whole‐body scans in order to assess the impact of the new software on pediatric soft‐tissue body composition estimates. Methods and Procedures: We reanalyzed 1,384 pediatric scans (for ages 1.7–17.2 years) using Hologic software V12.1, previously analyzed using V11.2. Regression analysis and ANCOVA were used to compare body fat (total body fat (TBF), percentage fat (%BF)), and non‐bone lean body mass (LBM) for the two versions, adjusting for gender, age and weight. Results: Software V12.1 yielded values that were higher for TBF, lower for LBM, and unchanged for DXA‐derived weight in subjects weighing <40 kg. Body composition values for younger, smaller subjects were most affected, and girls were more affected than boys. Using the new software, 14% of the girls and 10% of the boys were reclassified from the “normal” %BF range to “at risk of obesity,” while 7 and 5%, respectively, were reclassified as obese. Discussion: Hologic's newest DXA software has a significant effect on soft‐tissue results for children weighing <40 kg. The effect is greater for girls than boys. Comparison of TBF estimates with previous studies that use older DXA instruments and software should be done with caution. DXA has not yet achieved sufficient reliability to be considered a “gold standard” for body composition assessment in pediatric studies.     

The role of social factors and weight status in ideal body-shape preferences as perceived by Arab women

This study investigated the social factors associated with body-shape preferences for females and males as perceived by Arab women living in Qatar, and correlated the current weight status of women studied with these preferences. The subjects were 535 non-pregnant Arab women aged 20-67 years, who attended heath centres in Doha City, the capital of the State of Qatar. Illustrations of male and female body shapes ranging from very thin to very obese using the 9-figure Silhouettes scale were shown to women, and they were asked to select their preferred figure. Body mass index (BMI) was used to determine the weight status of women studied. Age, educational level and employment status were found to be significantly associated with ideal body-shape preference for both males and females, whereas marital status and current weight status had no significant association. In general, the Arab women studied selected a more mid-range of body fatness for males than for females. It is concluded that attention should be given to sociocultural factors, such as body-shape preferences, in any programmes to promote ideal body weight for the public.     

Body composition in adolescents: estimation by total body electrical conductivity

This comparative study, conducted on 28 boys and girls of widely varying fatness, was designed to validate a new whole-body composition method [total body electrical conductivity (TOBEC)], based on bioelectrical properties of the human body. A significant correlation [r = 0.911; standard error of the estimate (SEE) = 5.3 kg] was demonstrated between the transformed TOBEC scores (TOBEC0.5 X Ht) and lean body mass (LBM) determined by hydrodensitometry and corrected for individual variations in hydration (LBMd + W). TOBEC determinations also correlated well with 1) total body water determined by deuterium oxide dilution (r = 0.877; SEE = 4.5 liters), 2) total body potassium determined by means of a 4 pi whole-body counter (r = 0.860; SEE = 430.7 meq), 3) LBM derived from skinfold thicknesses (r = 0.850; SEE = 5.8 kg). The residuals of the regression between LBMd + W and TOBEC scores did not show any significant correlation with either the potassium or the water content of the LBM. The results indicate that TOBEC is a simple, rapid, reliable, and noninvasive technique for delineating changes in body composition that occur in children during growth.