Body fat percentages measured by dual-energy X-ray absorptiometry corresponding to recently recommended body mass index cutoffs for overweight and obesity in children and adolescents aged 3-18 y

BACKGROUND: Body mass index (BMI; in kg/m2) cutoffs for use with children and adolescents aged 2-18 y that correspond to the well-accepted BMI cutoffs for overweight (> or = 25 but < 30) and obesity (> or = 30) in adults were published recently. OBJECTIVE: The objective was to estimate the percentage body fat (%BF) values typically associated with these BMI cutoffs in children and adolescents. DESIGN: The %BF was measured by dual-energy X-ray absorptiometry in 661 subjects (49% male) aged 3-18 y. Regression equations using BMI, age, and sex were developed to predict the %BF associated with BMI cutoffs for overweight (age-specific BMI equivalent to a BMI of 25 in an 18-y-old) and obesity (age-specific BMI equivalent to a BMI of 30 in an 18-y-old) over this age range. RESULTS: Measurements classified 17.1% of males and 19.8% of females as overweight and 5.5% of males and 7.5% of females as obese. The %BF associated with an obese BMI tended to be higher in peripubertal males (34-36%) than in younger (24-30%) or older (27-30%) males. Although the predicted %BF of young females was similar to that of young males, values rose steadily with age, such that an 18-y-old female with a BMI of 30 had an estimated %BF of 42%, whereas that in males of similar age was 27%. CONCLUSION: The %BF values associated with BMI classifications of overweight and obesity vary considerably with age in growing children, particularly in girls.     

儿童高血压与体质量指数腰围腰高比及腰臀比的关联性研究

探讨儿童高血压与体质量指数(BMI)、腰围、腰高比、腰臀比的关联性,为儿童高血压和成年期高血压的早期预防提供参考.方法 以2014年安徽省学生体质与健康调研检测中的8 890名7~17岁儿童(男童4 424名,女童4 466名)作为研究对象,测量其身高、体重、腰围、臀围、血压,计算体质量指数、腰高比、腰臀比,并进行Z分转化.分析高血压与各项肥胖相关指标Z分间的关系,采用相关性分析、多元线性回归模型、ROC曲线分析.结果 8 890名儿童的高血压检出率为13.61%(95%CI=12.90%~14.32%),其中男生(16.30%,95%CI=15.21%~17.39%)高于女生(10.95%,95%CI=10.03% ~ 11.87%),差异有统计学意义(x2=54.06,P<0.01).BMI、腰围、腰高比、腰臀比4项人体测量指标Z分均呈正相关(P值均<0.01).Logistic回归分析得出,4项人体测量指标均为高血压的影响因素(P值均<0.01),其中男、女童BMI的Z分指标对高血压的影响最大,OR值分别为1.79(95%CI=1.66~1.93)和1.69(95%CI=1.56~1.84).ROC曲线结果显示,BMI、腰围的Z分指标与血压间的相关性较其他人体测量指标强.结论 BMI和腰围与7~17岁儿童高血压有良好的相关性.     

Waist circumference, body mass index, hip circumference and waist-to-hip ratio as predictors of cardiovascular disease in Aboriginal people

OBJECTIVE: To investigate waist circumference (WC), waist-hip ratio, hip circumference and body mass index (BMI) as risk factors for cardiovascular disease in Aboriginal Australians. METHODS: This cohort study included 836 adults aged 20-74 y in a remote Aboriginal community. WC, waist-hip ratio, hip circumference and BMI were obtained from a screening program. The participants were followed for up to 10 y for cardiovascular events. A Cox regression model was used to calculate the rate ratio (RR) and 95% confidence interval (CI) for the first-ever cardiovascular event (fatal and nonfatal). RESULTS: RRs for the first-ever cardiovascular event were 1.31 (95% CI: 1.11, 1.54), 1.29 (95% CI: 1.09,1.53), 1.28 (95% CI: 1.08, 1.52) and 1.10 (95% CI: 0.93, 1.30) per standard deviation increase in WC, BMI, hip circumference and waist-hip ratio, respectively, after adjustment for diabetes mellitus, total cholesterol, systolic blood pressure and smoking status. WC, BMI and hip circumference were significantly associated with cardiovascular risk, independent of other cardiovascular risk factors. Dividing each of the four parameters into quartiles, WC had the highest likelihood statistics (12.76) followed by BMI (11.45), hip circumference (10.57) and waist-hip ratio (3.15) for predicting first CV events. CONCLUSION: WC, BMI and hip circumference are associated with cardiovascular outcome, independent of traditional risk factors. However, WC appears to be a better predictor for cardiovascular risk than other parameters. Waist-hip ratio is not as useful as other measurements.     

Cut-off values of body mass index, waist circumference, and waist-to-height ratio to identify excess abdominal fat: population-based screening of Japanese school children

Background

School-based screening and prevention programs for adiposity generally target school children in grades 4 and 6 (age 9–11 years). The aims of this study were to evaluate the validity of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in identifying abdominal adiposity in fifth-grade Japanese school children and to determine optimal cut-off values for anthropometric measures.

Methods

The target population was fifth-grade school children enrolled in 2 schools in Shizuoka, Japan between 2008 and 2010; 422 of the 466 children participated in the present study. Abdominal adiposity was defined as percent trunk fat in the 95th percentile or higher, as determined by dual-energy x-ray absorptiometry (DXA). We analyzed the validity of BMI, WC, and WHtR using receiver operating characteristic (ROC) curve analysis. The Youden index was used to determine cut-off values of BMI, WC, and WHtR that identify excess abdominal fat.

Results

Optimal cut-off values to identify abdominal adiposity were 20.8 kg/m² (BMI), 76.5 cm (WC), and 0.519 (WHtR) for boys, and 19.6 kg/m² (BMI), 73.0 cm (WC), and 0.499 (WHtR) for girls. Areas under the ROC curve were 0.983 (BMI), 0.987 (WC), and 0.981 (WHtR) for boys, and 0.981 (BMI), 0986 (WC), and 0.992 (WHtR) for girls.

Conclusions

BMI, WC, and WHtR successfully identified a high proportion of children with excess abdominal fat as measured by DXA, demonstrating that these measures are useful indices for school screening.Key words: child, screening, obesity, statistics as topic, reference values     

南京市成年人体重指数、腰围、腰臀比、腰高比与高血糖关系的随访研究

目的 探讨南京市成年人BMI、腰围(WC)、腰臀比(WHR)和腰高比(WHtR)与高血糖发病危险的关系.方法 2004年7月对南京市3个城区和1个郊县的35岁以上居民开展横断面调查,对无高血糖的人群于2007年7月进行随访.采用多因素logistic回归和受试者工作特征曲线(ROC)评估基线4个肥胖指标对高血糖发生的预测作用.结果 基线调查时无高血糖者共3727名,3年后共随访3031名,随访率为81.3%.高血糖3年累计发病率为6.7%;男女性发病率差异无统计学意义(6.3%vs.7.0%).经多元线性回归分析,BMI、WC、WHR、WHtR平均增加一个单位,随访时空腹血糖值分别增加0.015 mmol/L、0.023 mmol/L、1.923 mmol/L、2.382 mmol/L.随着基线肥胖程度的增加,高血糖的发病危险增加.WHtR≥0.5者发生高血糖的风险,男性(OR=1.998,95%C1:1.231～3.212)和女性(OR=1.832,95%CI:1.157～2.902)均高于其他肥胖指标.4个肥胖指标中,ROC曲线下面积WHtR最大.结论 BMI、WC、WHR和WHtR值的上升均能增加高血糖发病的风险;而WHtR会成为预测高血糖的重要指标.     

Associations between the neighbourhood characteristics and body mass index,waist circumference,and waist-to-hip ratio: Findings from Alberta's Tomorrow Project

This study estimated the associations between neighbourhood characteristics and self-reported body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) risk categories among Canadian men and women. Using data from the Alberta's Tomorrow Project (n = 14,550), we estimated 3- and 4-way intersections, business destinations, population count, and normalized difference vegetation index (NDVI) within a 400 m radius of participant's home. Intersections, business destinations, and population count (z-scores) were summed to create a walkability score. Four-way intersections and walkability were negatively associated with overweight and obesity. Walkability was negatively associated with obesity. NDVI was negatively associated with high-risk WHR and population count and walkability positively associated with high-risk WHR. Among men, population count and walkability were negatively associated with obesity, and business destinations and walkability were negatively associated with overweight and obesity. Among women, NDVI was negatively associated with overweight (including obesity), obesity, and high-risk WC. Interventions promoting healthy weight could incorporate strategies that take into consideration local built environment characteristics.     

Relationship between body mass index, waist circumference, and waist-to-hip ratio and mortality in elderly women: a 5-year follow-up study

This study examines the association between body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC) and all-cause and cardiovascular mortality in elderly women in a 5-year longitudinal study of 575 female outpatients 60 years and over. The highest BMI, WHR, and WC quartiles and predefined BMI categories were analyzed as predictive variables. Death occurred in 88 (15.4%). Underweight (BMI < 18.5 kg/m2) was associated with all-cause mortality in uni- and multivariate analyses, regardless of age bracket. The survival curves and univariate analysis showed that the highest WHR quartile (> or = 0.97) was associated with all-cause mortality. However, after adjustment for age, smoking, and previous cardiovascular diseases, the increase in WHR was positively associated only in women from 60 to 80 years of age. None of the anthropometric measurements was associated with cardiovascular mortality. The results indicate that underweight and increased waist-to-hip ratio were predictors of all-cause mortality in elderly women, mainly among those under 80 years.     

上海市浦东新区15岁及以上居民体质指数、腰围、腰臀比与糖尿病患病的关系

目的 分析浦东新区≥ 15岁社区居民BMI、腰围、腰臀比与糖尿病患病的关系,为糖尿病防治策略的制定提供依据。方法 采用多阶段分层整群抽样方法,2016年对7 194名≥ 15岁社区居民进行问卷调查、体格检查和实验室检测,采用χ²检验、单因素线性相关、logistic回归分析BMI、腰围、腰臀比与糖尿病患病的相关性。结果 2016年浦东新区糖尿病粗患病率为27.37%,标化后为12.75%,男、女性之间患病率存在差异,男性略高于女性,糖尿病患病率随着年龄的增长呈上升趋势。FPG、餐后2 h血糖、糖化血红蛋白水平与BMI、腰围、腰臀比呈正相关。在调整混杂因素后,多元logistic回归分析结果显示,肥胖（OR=1.351,P<0.01）、腰围过大（OR=1.255,P<0.01）、腰臀比过高（OR=1.291,P<0.01）是糖尿病的危险因素。结论 肥胖、腰围、腰臀比的升高会增加糖尿病的患病风险,保持健康体重,尤其要防止腰围、腰臀比的升高,减少腹部脂肪的堆积,有利于降低糖尿病的患病风险。     

苏州市儿童青少年体质量指数腰围腰高比与血压偏高的关系

探讨苏州市儿童青少年体质量指数(BMI)、腰围和腰高比与血压偏高的关系,为制定适宜的儿童青少年血压综合防控策略和措施提供参考.方法 2019年9-10月采用分层整群抽样方法,对苏州市3 150名7~17岁儿童青少年进行问卷调查,测量身高、体重、腰围和血压,计算BMI和腰高比,分析血压偏高与各项肥胖指标的关系.结果 苏州市儿童青少年血压偏高率为11.3%,超重肥胖率为28.5%,采用腰围、腰高比标准筛查的中心性肥胖率分别为20.6%和23.7%.不同BMI、腰围和腰高比分组的儿童青少年血压偏高率差异均有统计学意义(x2值分别为157.80,105.87,124.17,P值均<0.01).Logistic回归分析显示,与正常体重组相比,超重肥胖组罹患血压偏高的可能性较大(OR=3.89,95%CI=3.09~4.90);与正常腰围或正常腰高比组相比,中心性肥胖组罹患血压偏高的可能性较大(腰围:OR=3.05,95%CI=2.41~3.86;腰高比:OR=3.35,95%CI=2.67~4.21).与BMI和腰围均正常者相比,同时超重肥胖和中心性肥胖者罹患血压偏高的可能性最大(OR=4.28,95%CI=3.31~5.53).结论 BMI、腰围和腰高比均与血压偏高存在相关,BMI与腰围或腰高比存在联合作用,保持正常体重和正常腰围/腰高比可能利于控制血压偏高.     

Effects of physical activity,body mass index,waist-to-hip ratio and waist circumference on total mortality risk in the Swedish National March Cohort

The health benefits of physical activity (PA) have been well documented. However, there is less research investigating whether or not these health benefits might differ among males and females or among subjects characterized by different levels of body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC). Baseline total PA, BMI, WHR and waist circumference were measured in 14,585 men and 26,144 women who participated in the Swedish National March. Their effects on all-cause mortality were analyzed with a follow-up time of almost 10 years. Sedentary men with a BMI ≥ 30 had a 98% (95% CI: 30–201%) increased risk of mortality compared to normal weight men with a high level of total PA. The same trend was observed for sedentary men with high WHR or waist circumference, compared to lean and highly active men. Sedentary women with a waist circumference of 88 cm or more had almost doubled, i.e. 97% (95% CI: 35–189%) increased mortality risk compared to physically active women with a waist circumference below 80 cm. BMI in men, but waist circumference in women better forecast all-cause mortality. We found no substantial effect modification between different measures of adiposity and physical activity—physical inactivity and obesity seem to increase total mortality risk independently and additively.     

Receiver-operating characteristic analyses of body mass index, waist circumference and waist-to-hip ratio for obesity: Screening in young adults in central south of China

BACKGROUND & AIMS: Recent data suggest that current obesity diagnostic criterion based on body mass index (BMI) above 30 in Caucasians may not be appropriate for Asian populations. Our aim was to identify the usefulness of BMI, waist circumference (WC) and waist-to-hip ratio (WHR) in screening for obesity in an Asian population. METHODS: A cross-sectional sample of 1109 males and 879 females aged 20-45-yr were recruited. Height, weight, WC, hip circumference and percentage body fat (PBF) were measured in all subjects. Then receiver-operating characteristic analyses were used to evaluate the performances of the three anthropometric indices. RESULTS: BMI, WC and WHR showed strong positive correlation with PBF (r=0.47-0.75) in both males and females within both age groups. True-positive rates ranged from 82.4% to 94.1% and 68.8% to 86.3% in males and females, respectively. True-negative rates ranged from 64.1% to 84.7% and from 56.9% to 79.0%, respectively. The areas under the curves (AUCs) for WC and BMI were high (0.76-0.92) in both sexes and divided age groups (20-30-yr and 31-45-yr), and those for WHR were a little lower (0.74-0.88). CONCLUSIONS: BMI and WC are two important predictors for obesity in Chinese, and WHR is an alternative.     

Waist-to-height ratio, waist circumference, and body mass index as indices of cardiometabolic risk among 36,642 Taiwanese adults

Purpose

We aimed to investigate the association of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) with cardiometabolic risk.

Methods

In this cross-sectional study, 21,038 men and 15,604 women who participated in a health check-up were included.

Results

In both men and women, the area under the curve (AUC) of WHtR was significantly greater than that of BMI or WC in the prediction of diabetes, hypertension, high total cholesterol, high triglycerides, and low HDL-cholesterol (P < 0.05 for all). The AUC for WHtR in the prediction of metabolic syndrome (MS) was also highest in the women (P < 0.05). After adjustment for potential confounders, the odds ratios and 95% confidence intervals for MS for each standard deviation increase in BMI, WHtR, and WC were 1.47 (1.46–1.49), 1.32 (1.31–1.33), and 1.19 (1.18–1.19), respectively. Finally, patients of either sex with a normal BMI or WC level, but with an elevated WHtR, had higher levels of various cardiometabolic risk factors in comparison with their normal BMI or WC, but low WHtR, counterparts (P < 0.05 for all).

Conclusion

Among Taiwanese adults, a WHtR greater than 0.5 is a simple, yet effective indicator of centralized obesity and associated cardiometabolic risk, even among individuals deemed ‘healthy’ according to BMI and WC.     

Body mass index (BMI) and waist circumference (WC) as screening tools for cardiovascular risk factors in Guadeloupean women

Hypertension, dyslipidemia and type 2 diabetes, important cardiovascular risk factors, are strongly linked to obesity. Body mass index (BMI) and waist circumference (WC) are measures of obesity that can be useful in identifying individuals with these risk factors. We assessed which of the two measures is more informative at the population level. The study population included 5,149 consecutive women aged 18 to 74 recruited in an Health Center of Guadeloupe (FWI) in 1999. The areas under the ROC curves of BMI and WC and their 95% CI were computed and compared. Logistic regression analysis of BMI and WC and the areas under the ROC curves in two separate age groups (18-39 years and 40-74 years) showed that age modifies the discriminant ability of these parameters in identifying the CVD risk factors. Sensitivity equalled specificity at levels between 52-70% for BMI and 55-80% for WC. ROC areas for identifying each risk factors by BMI varied from 0.52 to 0.84 and by WC from 0.55 to 0.88. For the identifying of women with at least one CVD risk factor, in the whole population, the areas under the curves for BMI and WC (respectively, 0.71; 95% CI: 0.69-0.73 and 0.76; 95% CI: 0.74-0.78) were both significantly greater than 0.5. The difference between these correlated areas was 0.04, 95% CI [-0.05, -0.03]. The lowest values of the areas were noted in detecting women with dyslipidemia and the highest in detecting those with type 2 diabetes. Waist circumference, a practical tool that had a higher discriminant ability than BMI in identifying presence or absence of all these risk factors, appears as the best screening tool in this population.     

Frequency of soup intake is inversely associated with body mass index, waist circumference, and waist-to-hip ratio, but not with other metabolic risk factors in Japanese men

Several previous studies have shown that the intake of soup negatively correlates with the body mass index (BMI), serum cholesterol and triacylglycerol levels, and blood pressure, suggesting that soup intake reduces metabolic risk. However, the correlation between soup intake and various metabolic risk factors has not been well-established. Especially, it has not been investigated in Asian countries. The aim of this study was to investigate the association of the frequency of soup intake and metabolic risk factors such as BMI, waist circumference, waist-to-hip ratio, serum cholesterol, serum triacylglycerol, blood glucose, and glycated hemoglobin. A cross-sectional study of 103 Japanese men aged 24 to 75 years was conducted. The intake of soup and other food was investigated by semi-quantitative food frequency questionnaires. The correlation between the frequency of soup intake and metabolic risk factors was analyzed by multiple regression analysis with a linear model. The median value of frequency of soup intake was 7.0 times per week. After adjusting for confounding factors such as age, energy intake, energy from alcohol intake, current smoking, and estimated energy expenditure, the frequency of soup intake was found to have a significant inverse association with BMI (P=0.040), waist circumference (P=0.024), and waist-to-hip ratio (P=0.001). However, no significant associations with other metabolic risk factors were found. Frequency of soup intake is negatively correlated with obesity-related physical parameters in Japanese men.     

南京市3~6岁儿童腰围、臀围变化及体格相关指标关系分析

目的 了解南京市3~6岁儿童腰围、臀围、腰臀比的现状及其与体格相关指标的关系,有针对性地制定措施,更好地促进儿童健康成长。方法 2015年采用分层随机整群抽样的方法调查南京市4 300名3~6岁儿童的腰围、臀围指标,计算腰臀比并对体格相关指标进行分析。结果 男、女童腰围、臀围均随着年龄的增加而增加,腰臀比随着年龄的增加而降低。平均腰围:男童49.4~54.5 cm,女童47.5~53.2 cm;平均臀围:男童53.3~62.5 cm,女童53.0~60.9 cm;平均腰臀比:男童0.87~0.96 cm,女童0.87~0.90 cm。儿童腰围、臀围及腰臀比在性别年龄组间差异有统计学。腰围和臀围分别与体重、身高及体重指数(BMI)呈正相关。腰臀比随着年龄的增加而降低,与身高、臀围呈负相关。结论 南京市3~6岁儿童腰围、臀围存在年龄和性别差异,腰围、臀围、腰臀比与其体重、身高及BMI有关。     

A composite score combining waist circumference and body mass index more accurately predicts body fat percentage in 6- to 13-year-old children

Purpose

Body mass index (BMI) and waist circumference (WC) are widely used to predict % body fat (BF) and classify degrees of pediatric adiposity. However, both measures have limitations. The aim of this study was to evaluate whether a combination of WC and BMI would more accurately predict %BF than either alone.

Methods

In a nationally representative sample of 2,303 6- to 13-year-old Swiss children, weight, height, and WC were measured, and %BF was determined from multiple skinfold thicknesses. Regression and receiver operating characteristic (ROC) curves were used to evaluate the combination of WC and BMI in predicting %BF against WC or BMI alone. An optimized composite score (CS) was generated.

Results

A quadratic polynomial combination of WC and BMI led to a better prediction of %BF (r ² = 0.68) compared with the two measures alone (r ² = 0.58–0.62). The areas under the ROC curve for the CS [0.6 * WC-SDS + 0.4 * BMI-SDS] ranged from 0.962 ± 0.0053 (overweight girls) to 0.982 ± 0.0046 (obese boys) and were somewhat greater than the AUCs for either BMI or WC alone. At a given specificity, the sensitivity of the prediction of overweight and obesity based on the CS was higher than that based on either WC or BMI alone, although the improvement was small.

Conclusion

Both BMI and WC are good predictors of %BF in primary school children. However, a composite score incorporating both measures increased sensitivity at a constant specificity as compared to the individual measures. It may therefore be a useful tool for clinical and epidemiological studies of pediatric adiposity.     

腰围、腰围身高比、体重指数预测儿童青少年代谢紊乱的效果比较

目的 探讨腰围(WC)、腰围身高比(WHtR)和体重指数(BMI)预测儿童青少年代谢紊乱的效果,为儿童青少年代谢紊乱的早期预警提供科学依据。方法 选取济南市城区1 170名7~17 岁儿童青少年,利用受试者工作特征曲线(ROC)比较WC、WHtR和BMI预测代谢紊乱的曲线下面积(AUC),采用Logistic回归模型分析WC、WHtR和BMI诊断的肥胖预测儿童青少年代谢紊乱的风险。结果 WC预测4种代谢紊乱(高血糖、高血压、低HDL-C和高TG)中≥1项或≥2项组分的ROC曲线下面积(AUC,95%CI)分别为0.63(0.59~0.66)和0.74(0.69~0.79),WHtR对应值分别为0.62(0.58~0.65)和0.74(0.69~0.79),BMI对应值分别为0.64(0.60~0.67)和0.75(0.70~0.80)。WC诊断的腹型肥胖(WC≥性别和年龄别的P₉₀)预测儿童青少年4种代谢紊乱中的≥1项或≥2项组分的OR(95%CI)值分别为2.88(2.15~3.86)和6.83(4.47~10.44),WHtR诊断的腹型肥胖(WHtR≥0.50)对应的OR(95%CI)值分别为2.63(1.86~3.71)和5.77(3.65~9.13),BMI诊断的肥胖(BMI≥性别和年龄别的肥胖界值) 对应的OR(95%CI)值分别为3.03(2.17~4.23)和6.35(4.03~10.00)。结论 WC、WHtR和BMI均可作为儿童青少年代谢紊乱的重要预测因子,WC、WHtR和BMI预测代谢紊乱的效果相当。考虑到WHtR 界值的简单易记性,WHtR或许可替代WC和BMI作为儿童青少年代谢紊乱的早期预警指标。     

Determination of skeletal muscle and fat-free mass by nuclear and dual-energy x-ray absorptiometry methods in men and women aged 51-84 y (1-3).

BACKGROUND: Skeletal muscle mass (SMM) and fat-free mass (FFM) are important variables in nutritional studies. Accurate techniques for measuring these variables have not been thoroughly validated in elderly subjects. OBJECTIVES: The objectives of this study were to 1) compare SMM values derived from dual-energy X-ray absorptiometry (DXA) with those calculated by a nuclear method from total body potassium (TBK) and total body nitrogen (TBN) measurement (both: KN) in older subjects, and 2) assess the accuracy of FFM measurement by DXA in these subjects. DESIGN: TBK, TBN, DXA (model XR36; Norland, Fort Atkinson, WI), bioimpedance, and anthropometric measurements were performed on healthy women (n = 50) and men (n = 25) aged 51-84 y. RESULTS: Mean SMM by KN was not significantly different from SMM by DXA in either sex. SMM by KN predicted SMM by DXA with an SEE of 2.1 kg (r = 0.95, P < 0.0001 for women and men together). In the men, FFM by DXA agreed well with FFM estimated by TBK, skinfold thicknesses, bioimpedance analysis, and a multicompartment model. In women, FFM by DXA was 4-5 kg less than that by the other methods (P < 0.01). Truncal fat was related to intermethod FFM differences (r = 0.58, P < 0.0001). CONCLUSIONS: These data indicate that 1) either the nuclear or the DXA method can be applied to estimate SMM in healthy older subjects, and 2) the Norland DXA instrument significantly underestimates FFM in older women, in part, because of the influence of truncal adiposity.