Percent Fat-free Mass Research Articles

Use of bioelectrical impedance analysis to assess body composition in rural Gambian children

To validate the Tanita BC-418MA Segmental Body Composition Analyser and four-site skinfold measurements for the prediction of total body water (TBW), percentage fat-free mass (%FFM) and percentage body fat (%BF) in a population of rural Gambian children. One hundred and thirty-three healthy Gambian children (65 males and 68 females). FFM estimated by the inbuilt equations supplied with the Tanita system was assessed by comparison with deuterium oxide dilution and novel prediction equations were produced. Deuterium oxide dilution was also used to develop equations for %BF based on four-site skinfolds (biceps, triceps, subscapular and suprailiac). The inbuilt equations underestimated FFM compared to deuterium oxide dilution in all the sex and age categories (P<0.003), with greater accuracy in younger children and in males. The best prediction of %FFM was obtained from the variables height, weight, sex, impedance, age and four skinfold thickness measurements (adjusted R(2)=0.84, root mean square error (MSE)=2.07%). These data suggest that the Tanita instrument may be a reliable field assessment technique in African children, when using population and gender-specific equations to convert impedance measurements into estimates of FFM.

Serum sodium and hydration status predict transplant‐free survival independent of MELD score in patients with cirrhosis

Serum sodium may have prognostic value in addition to the model for end-stage liver disease (MELD) score for prediction of early mortality in patients listed for liver transplant. In patients with cirrhosis, over-hydration is a common feature but its prognostic value has not been evaluated. This study examines the independent prognostic significance of MELD, serum sodium and hydration status on long-term survival in patients with cirrhosis. Serum sodium and hydration (total body water as a percentage of fat-free mass) were measured in 227 consecutive cirrhotic patients (146 male, 81 female; median age 49 years, range 19-73 years; median MELD score 13, range 6-36). Patients with hepatocellular carcinoma or listed for liver transplantation at the time of initial assessment were excluded. A competing risks Cox proportional hazards analysis was performed to evaluate the influence of MELD, sodium and hydration on risk of death or transplant. Median follow-up was 52 (range 4-93) months. Serum sodium and hydration were each associated with reduction in time to death or transplant on univariate analysis (sodium: hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.87-0.94, P < 0.0001; hydration: HR 1.20, 95% CI 1.10-1.30, P < 0.0001). On multivariate analysis, MELD, serum sodium and hydration were independently predictive of death or transplant (MELD: HR 1.12, 95% CI 1.06-1.19, P < 0.0001; sodium: HR 0.93, 95% CI 0.87-0.99, P = 0.04; hydration: HR 1.17, 95% CI 1.02-1.33, P = 0.02). In non-waitlisted patients with cirrhosis, serum sodium is predictive of transplant or death independent of MELD score.

Validation of hand‐held bioelectrical impedance analysis with magnetic resonance imaging for the assessment of body composition in overweight women

Methods of assessing body composition suitable for use in clinical trials should be accurate, reliable, and easy to perform. One such technique routinely implemented is hand-held bioelectrical impedance analysis (BIA). The validity of this method, however, in body composition assessment of overweight women is not known. The aim of this study was to validate the hand-held BIA technique with magnetic resonance imaging (MRI) for the assessment of body composition in overweight women. Fat mass, percent fat mass, fat-free mass, and percent fat-free mass values estimated by hand-held BIA were compared to those measured by MRI. Thirty-one Caucasian women (50.1 +/- 8.2 years, body mass index of 26.9 +/- 3.1 kg/m(2)) participated in the study. BIA measurements were highly reproducible (technical error (TE) was 0.06 +/- 0.07 kg for fat mass and 0.08 +/- 0.11% for percent fat mass), but were significantly different (P < 0.0001) for each body composition parameter when compared to MRI. BIA underestimated fat mass by 2.3 +/- 3.3 kg and percent fat mass by 5.6 +/- 3.9%. Likewise, BIA overestimated fat free mass by 7.4 +/- 2.7 kg and percent fat free mass by 5.6 +/- 3.2%. No relationship between the bias and the mean of the two measurements was noted suggesting that bias is not related to measurement size. Although hand-held BIA gives reproducible findings, the bias noted for all body composition parameters puts into question the validity of this regional impedance device for use in clinical trials in overweight women.

Supplementation with Soy-Protein−Rich Foods Does Not Enhance Weight Loss

The objective of this study was to determine whether a weight-loss diet high in soy-protein−rich foods leads to greater weight loss and reductions in waist circumference, fat mass, and cardiovascular disease risk factors than a control diet. Groups of overweight women (body mass index [calculated as kg/m 2] of 28 to 33, aged 25 to 49 years) were counseled to decrease their caloric intake by 500 kcal/day for a period of 12 weeks; in addition, the soy-protein−rich group was counseled to consume 15 g soy protein/1,000 kcal daily. Soy-protein−rich foods were provided to subjects. Body weight, waist circumference, percent body fat, fat-free mass, lipids, glucose, and insulin were measured at repeated intervals. Forty-seven women completed the study. Both groups lost a similar amount of weight both when a completers only (−3.18%±0.63% vs −4.04%±0.95% for soy-protein−rich and control diets, respectively) and a last-observation-carried-forward analysis (−1.93%±0.50% vs −2.50%±0.67%, for soy-protein−rich and control diets, respectively) were performed. There was no difference between groups in change in percent fat mass (−5.31%±1.50% for soy-protein−rich diet vs −3.94%±1.68% for control diet), percent fat-free mass, and waist circumference. There was no dietary assignment-by-group interaction on lipid, glucose, and insulin concentrations when analyses were done on completers only or on all subjects using a last-observation-carried-forward approach. Percent change in any of the biochemical parameters studied over the 12-week period was not significantly different between groups. Our results do not lend support to the emerging notion that soy-protein−rich foods could be considered potential functional foods for weight management, in the quantities consumed in this study.

Resting energy expenditure is not increased in mildly hyperglycaemic obese diabetic patients

Resting energy expenditure (REE) is believed to be increased in type 2 diabetes, an increase that is associated with deteriorating glucose tolerance during its development. Meanwhile, insulin resistance, a state linked to obesity and observed in all type 2 diabetic patients, is associated with reduced REE. Our aim was to compare REE in obese patients with and without diabetes. REE, body composition (total body water, density, percentage fat and fat-free mass: 3-compartment model) and metabolic control were assessed in fifty obese Caucasian patients with diabetes (glycated haemoglobin level 7.6 (SD 1.5) %) and fifty obese patients who were non-diabetic. Despite being more overweight and younger, obese non-diabetic patients had an absolute REE (7.73 (SD 1.44) v. 8.12 (SD 1.37) MJ; P=0.17) and percentage fat-free mass similar to those of obese diabetic patients. Even when adjusted for differences in body composition, REE remained similar in both groups. Furthermore, REE (absolute and adjusted) was unaffected by both glucose level and control (glycated haemoglobin), with fat-free mass being the only determinant of REE. We conclude that REE is not necessarily increased by the presence of diabetes in obese people.

Negative energy balance in male and female rangers: effects of 7 d of sustained exercise and food deprivation

A challenging 7-d ranger field exercise (FEX) by cadets in the Norwegian Military Academy provided a venue in which to study the effects of negative energy balance. We quantified total energy expenditure (TEE), food intake, and changes in body composition in male and female cadets. TEE (measured by doubly labeled water), food intake, activity patterns (measured by accelerometry), and body composition (measured by dual-energy X-ray absorptiometry) were measured in 16 cadets (10 men and 6 women aged 21-27 y). The physically active (approximately 23 h/d) and semistarved (0.2-2.2 MJ/d) cadets lost weight (x +/- SD: men, -7.7 +/- 1.1 kg; women, -5.9 +/- 1.1 kg; P < 0.05). Absolute TEE differed by sex (men, 26.6 +/- 2.0 MJ/d; women, 21.9 +/- 2.0 MJ/d; P < 0.05) but body weight-specific TEE did not (men, 343 +/- 26 kJ . kg(-1) . d(-1); women, 354 +/- 18 kJ . kg(-1) . d(-1); NS). Fat-free mass (FFM) loss differed significantly by sex (men, -4.0 +/- 1.2 kg; women, -2.5 +/- 1.1 kg; P < 0.05), but percentage FFM loss did not (men, -6.3 +/- 1.9%; women, -5.6 +/- 2.4%). In contrast, absolute FM loss did not differ significantly by sex (men, -3.45 +/- 0.72 kg; women, -3.42 +/- 0.22 kg), but fat oxidation (men, 5.2 +/- 1.0 mg . min(-1) . kg FFM(-1); women, 7.3 +/- 0.5 mg . min(-1) . kg FFM(-1)) and the relative contribution of FM to TEE (men, 74 +/- 14%; women, 89 +/- 6%) were significantly greater in women than in men (P < 0.05). Female cadets maintained a significantly more fat-predominant fuel metabolism than did male cadets in response to sustained exercise and semistarvation.

A new device for measuring resting energy expenditure (REE) in healthy subjects

Background and aim Lifestyle change targeted towards increasing daily resting energy expenditure (REE) is one of the cornerstones of obesity treatment. Measurements of energy expenditure and substrate utilization are essential to understanding the metabolic basis of obesity, and the physiological responses to perturbations in habitual food intake. REE is the largest part of human energy expenditure (60-70%) and an increase or decrease in REE would have a large impact on total energy. Accurate and easy-to-use methods for measuring REE are needed, to be applied by clinicians in daily clinical settings to assess the validity of a new instrument to estimate REE in normal weight, healthy adults. Methods Ninety-nine subjects (52 females and 47 males) (mean ± SD, age 38 ± 14 years; body mass index (BMI) 23 ± 3 kg/m 2) were tested. REE was assessed using a Sensor Medics Vmax metabolic cart with a ventilated canopy and with the SenseWear armband. Body composition, percentage fat mass (%FM) and percentage fat free mass (%FFM) were assessed by skinfold thickness measurements (SF), bio-electrical impedance analysis (BIA) and air displacement plethysmography (BOD-POD). Results No significant difference was found among measurements of FFM using the three different techniques. Both SenseWear and Sensor Medics Vmax showed a high correlation, r = 0.42 and r = 0.40 ( p < 0.0001) respectively, with BMI. No significant difference was found in mean REE between SenseWear (1540 ± 280 kcal/day) and Sensor Medics Vmax (1700 ± 330 kcal/day) ( p = ns) and the correlation between REE measured by SenseWear and Sensor Medics Vmax was high ( r = 0.86, p < 0.0001). Bland–Altman plot showed no difference in REE determination between SenseWear and Sensor Medics Vmax. %FFM determined by BOD-POD correlated with SenseWear ( r = 0.42, p < 0.0001) as well as Sensor Medics Vmax ( r = 0.38, p < 0.001). Conclusion SF, BIA and BOD-POD provide valid and reliable measurements of FFM. Our results suggest that the SenseWear armband is an acceptable device to accurately measure REE in healthy subjects. Its characteristics have the potential to reduce measurement times and make the SenseWear armband useful for epidemiological studies.

The effects of balanced low calorie diet on body composition and serum leptin of obese women

The effect of balanced low-calorie diet for 14 days on body weight (BW), body mass index (BMI), total skin fold thickness (SFT), fat mass (FM), fat free mass (FFM), waist to hip ratio (WHR) and serum leptin level was evaluated by using a pre and post-experimental balanced low-calorie diet 915.23 kcal/day with the composition of 55.81% carbohydrate, 19.46% protein and 24.73% fat for 14 days on 39 obesewomen subjects (19-55 years old) who have met the inclusion and exclusion criteria. The collected data include demographic characteristic, macronutrient and energy intake, as well as of anthropometry, FM, FFM, and serum leptin level. Body weight reduction occurs significantly (p<0.05) from 70.99 ± 8.62 to 68.81 ± 8.36 kg (3.07%); BMI reduction is significant (p<0.05) from 30.28 ± 3.11 kg/m2 to 29.36 ± 2.94 kg/m2 (3.04%); Significantly reduced SFT (p<0.05) from 99.36 ± 12.07 mm to 91.29 ± 10.85 mm (8.08%); Significantly reduced FM (p<0.05) from 35.41 ± 2.75 % to 33.65 ± 2.73% (1.76%); Significantly increased FFM percentage (p<0.05) from 64.59 ± 2.74 to 66.35 ± 2.73 (2.72%); Significantly reduced WC (waist circumference) (p<0.05) from 85.87 ± 7.31 to 83.35 ± 7.09 (2.93%); Significantly reduced HC (hip circumference) (p<0.05) from 107.59 ± 6.67 to 106.49 ± 6.37 (1.02%); Significantly reduced WHR (p<0.05) from 0.80 ± 0.05 to 0.78 ± 0.04 (2.24%); Significantly reduced serum leptin (p<0.05) from 23.31 (12.06-71.22) to 18.18 (7.90-65.11) (22.01%); positive correlation is observed between serum leptin level and FM significantly (p<0.05) before treatment (r=0.47 ; p=0.003) and after treatment (r=0.57 ; p=0.001). Balanced low-calorie diet may effectively reduce body weight, BMI, skin fold thickness, percentage of fat mass, to increase percentage of fat free mass, to reduce waist to hip ratio and serum leptin level. (Med J Indones 2005; 14: 220-4) Keywords: Balanced low-calorie diet, obesity, leptin, body composition

Body composition in young adult survivors of childhood acute lymphoblastic leukaemia

Obesity is frequently reported in patients treated for childhood leukaemia. Obesity, particularly abdominal obesity, is one of the main characteristics of the metabolic syndrome and a risk factor for cardiovascular disease and non-insulin-dependent diabetes mellitus (NIDDM). All patients treated for acute lymphoblastic leukaemia (ALL) before the onset of puberty in the region of western Sweden, between 1973 and 1985, and in first remission, were included. 35 out of 47 patients aged 20-32 years participated. 19 patients had received cranial radiotherapy, and the median follow-up time was 20 years. The focus of this report was to study body composition and signs of the metabolic syndrome and correlate the findings to spontaneous growth hormone (GH) secretion. Body composition was assessed using dual-energy X-ray absorbtiometry (DEXA). We analyzed serum concentrations of insulin, glucose, leptin and lipids. No patient was obese according to World Health Organization criteria (body mass index, BMI > or = 30 kg/m2) but one-third were overweight (BMI 25-29.9 kg/m2). The maximal GH peak during 24 h (GHmax) was correlated to percentage of total body fat (r = -0.42; P = 0.017), trunk fat (r = -0.5; P = 0.005) and fat-free mass (r = 0.42; P = 0.017). GHmax was also correlated to s-triglycerides (r = -0.54; P = 0.001), low-density lipoprotein-cholesterol (r = -0.382; P = 0.024) and high-density lipoprotein-cholesterol (r = 0.45; P = 0.007). We found little effect on BMI but an increased percentage of total body fat, especially trunk fat, and a tendency for an unfavourable lipid profile in adult survivors of childhood leukaemia. These findings were related to low endogenous GH secretion due to cranial irradiation.

Haplotypes in the phospholipid transfer protein gene are associated with obesity-related phenotypes: the Québec Family Study

The phospholipid transfer protein (PLTP) may play a role in body fat regulation. To investigate the association between PLTP genetic variants and obesity-related phenotypes. Two intronic variants, one in intron 1 (c.-87G>A) and the other in intron 12 (c.1175+68T>G), were genotyped in 811 participants of the Québec Family Study. Nine obesity-related phenotypes were investigated, including body mass index (BMI), obesity (BMI> or =30 kg/m(2)), and waist circumference, percentage of fat, fat mass and fat-free mass measured by hydrostatic weighing as well as total, visceral and subcutaneous abdominal adipose tissue areas assessed by computed tomography. Single markers and haplotypes were tested for associations in family-based designs using the FBAT program. The SNP located in intron 1 showed significant associations with obesity, BMI, waist circumference and fat-free mass (P<0.05). The low-frequency allele (A allele) was associated with higher trait values, suggesting that the transmission of this allele is associated with an increased risk of being obese. Significant associations were observed between haplotypes and obesity, waist circumference, percentage of fat and fat-free mass (P<0.05). The transmission of the AT haplotype (frequency=0.180) was positively associated with obesity-related phenotypes. After sequencing the promoter and the coding regions of the PLTP gene, we were unable to identify a mutation that could replicate these results. Intronic variants of the PLTP gene are significantly associated with obesity-related phenotypes. Considering the number and the relevance of candidate genes surrounding the PLTP locus and the absence of missense polymorphisms in the coding region, the associations could be mediated by a second gene allele in linkage disequilibrium with the marker locus.

Limitations and validation of bioelectrical impedance analysis in morbidly obese patients

Several factors limit the use of bioelectrical impedance analysis as a valid predictor of the amount of body fat in morbidly obese individuals. The purpose of this review is to examine the theory and assumptions that may limit the use of bioelectrical impedance analysis in such individuals. There is currently insufficient validation of bioelectrical impedance analysis equations in obese individuals with body mass indices greater than 34 kg/m. Several factors limit the application of bioelectrical impedance analysis in morbidly obese individuals. Obese individuals have a relatively high amount of extracellular water and total body water, which may overestimate fat-free mass and underestimate fat mass. Central body fat will generally overestimate the percentage of fat-free mass and underestimate the percentage of fat mass in overweight and obese adults with the use of prediction formulas developed in normal weight individuals. A relatively increased amount of total body water and a relative increase in extracellular water will result in an underestimation of the percentage of body fat and an overestimation of fat-free mass in the morbid obesity state. A different body build disposition (mainly in those with severe abdominal obesity) will result in an overestimation of the percentage of body fat. New equations are needed to validate bioelectrical impedance analysis in morbidly obese patients.

Changes in body composition, physical performance and cardiovascular risk factors after a 3-week integrated body weight reduction program and after 1-y follow-up in severely obese men and women

To investigate the short- and medium-term (ie, at 1-y follow-up) effects of a hospital-based body weight reduction (BWR) program lasting 3 weeks in severely obese individuals. Longitudinal, clinical intervention study entailing energy-restricted diet, tailored aerobic-strength exercise, psychological counselling and nutritional education during a 3-week period followed by 49 weeks of indirect supervision at home. In all, 45 women and 19 men aged 30.2 +/- 7.2 y (mean +/- s.d.) with severe obesity (BMI: 41.3 +/- 4.3 kg/m(2)), classified as weight losers (final < initial weight) and regainers (final> or =initial weight). Body composition, physical performance and cardiovascular risk factors before and after the BWR program and at follow-up. The large majority of the experimental subjects obtained a clinical success after the 1-y period, and the rate was higher in females (n = 37/45, ie, 82.2%) than in males (n = 11/19, ie, 57.9%). At follow-up, weight losers had higher percent fat-free mass, muscle strength, HDL-cholesterol and self-reported physical activity level and lower total cholesterol and glucose levels than weight regainers (P < 0.05-0.01). Males displayed significantly larger fat-free mass losses than females at post-BWR and at follow-up. CONCLUSIONS A 3-week hospital-based integrated BWR program resulted in a high rate of clinical success in severely obese individuals at 1-y follow-up (particularly in females), that was associated with increased levels of self-reported physical activity and improved muscle strength and lipid profile. Further research is needed to establish the long-term effects (ie, at 2-5 y) associated to this treatment.

Effect of a 3-week body mass reduction program on body composition, muscle function and motor performance in pubertal obese boys and girls

The aim of this study was to investigate the effects of a multidisciplinary body mass reduction (BMR) program on body composition, muscle function and motor performance in 50 obese [mean body mass index (BMI): 35.9+/-5.8 kg/m2] boys and girls aged 12-17 yr (Tanner stage III, IV and V). The hospital-based BMR program combined an energy-restricted diet (1400-1600 kcal), nutritional education, psychological counselling and moderate physical activity (45-60 min/ session; 5 sessions/week; 60-80% of the maximal heart rate) during a 3-week period. Fat mass, fat-free mass, maximal power during jumping and stair climbing as well as maximal strength of the upper and lower limb muscles were quantified before and after the treatment. Body mass and fat mass significantly decreased following the BMR program, respectively -5.1 and -7.8% (p<0.001), while percent fat-free mass increased 2.3% (p<0.001). The treatment significantly increased both stair climbing and jumping power, respectively 8.2 and 8.9% (p<0.05), and the same was true for maximal strength of the upper and lower limb muscles (p<0.001). For the first time, it was demonstrated that a BMR program entailing diet and physical exercise significantly improved body composition, muscle function and motor performance in obese boys and girls aged 12-17 yr, while gender and pubertal stages had no influence on BMR program-induced changes.

Body composition by bioelectrical impedance analysis in renal transplant recipients

Bioelectrical impedance analysis was introduced more than a decade ago to measure body composition and nutritional status. There are presently limited data on the nutritional status and body composition measured with bioelectrical impedance analysis in renal transplant recipients, especially among the Asian population. The normal values for these data in renal transplant recipients remain unknown. Methods All renal transplant recipients with stable graft function who attended the outpatient renal transplant clinic in June 2003 were recruited for this cross-sectional study. Demographic and clinical data were obtained from participating patients and their outpatient clinic notes. Body composition and bioelectrical impedance data were obtained using the Metron BioScan 916 v3 analyzer. Results Out of a total of 168 renal transplant recipients, 110 participated in this study of body composition and bioelectrical impedance for comparison with data from a previous study of 419 normal healthy volunteer controls. When compared to the healthy Malaysians, renal transplant recipients showed similar body composition in terms of body mass index, body cell mass, muscle bulk, percentage of body fat, percentage of fat free mass, and percentage of total body water. However, renal transplant recipients have more extracellular water, a lower phase angle, and a lower reactant. Conclusion Malaysians who have undergone renal transplantation have similar body composition to the healthy Malaysians when measurements are obtained using bioelectrical impedance analysis.

Physical Frailty and Body Composition in Obese Elderly Men and Women

To evaluate the prevalence of frailty and interrelationships among body composition, physical function, and quality of life in community-dwelling obese elderly (OE) persons. Fifty-two OE, 52 nonobese frail, and 52 nonobese nonfrail subjects, matched for age and sex, were studied. Subjective and objective measures of functional status were evaluated by using the physical performance test, exercise stress test, lower extremity (LE) strength, gait speed, static and dynamic balance, functional status questionnaires, and health-related quality-of-life questionnaire (Medical Outcomes Short Form). Body composition was evaluated by using DXA, and muscle quality was evaluated by determining the ratio of LE strength to LE lean mass. Among OE subjects, 96% met our standard criteria for mild to moderate frailty. Compared with the nonobese nonfrail group, the OE and nonobese frail groups had lower and similar scores in physical performance test, peak aerobic power, and functional status questionnaire, and exhibited similar impairments in strength, walking speed, balance, and health-related quality of life. Although absolute fat-free mass (FFM) was greater, the percentage body weight as FFM and muscle quality was lower in the OE group than in the other two groups. Physical frailty, which predisposes to loss of independence, is common in community-living OE men and women. Physical frailty in OE subjects was associated with low percentage FFM, poor muscle quality, and decreased quality of life. These findings suggest that weight loss therapy may be particularly important in OE persons to improve physical function, in addition to improving the medical complications associated with obesity.

Inflammation rather than nutritional depletion determines glutamine concentrations and intestinal permeability

Aim: Nutritional depletion has been correlated with low plasma and mucosal glutamine concentrations and with increased intestinal permeability. Since nutritional depletion often is associated with (chronic) inflammatory stress, this study was designed to establish the influence of depletion and inflammation on glutamine concentrations and gut barrier function. Methods: Anthropometric parameters were calculated from 26 patients who required artificial nutrition. Glutamine concentrations in plasma and gut mucosa, gut permeability and mucosal morphology were assessed. For determination of the degree of inflammation erythrocyte sedimentation rates and (pre)albumin concentrations were measured. On the basis of these parameters patients were divided into two groups having significant inflammatory stress or not. Similarly, a depleted and a non-depleted group was formed based on percentage ideal body weight, fat-free mass index (FFMI) and percentage weight loss. Glutamine concentrations, gut permeability and villus morphology were compared between the groups. Results: The presence of inflammatory activity had significant negative effects on glutamine concentrations in contrast to the presence or absence of nutritional depletion. Similarly, intestinal permeability increased during active inflammation but not in depleted patients. FFMI but not inflammation was related to villus height. Conclusions: The presence of inflammation significantly affects glutamine concentrations and gut permeability, in contrast to the presence of depletion of body cell mass per se. On the other hand, villus morphology is not influenced by changes in systemic inflammatory activity whereas nutritional status possibly does affect villus height.

Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged &gt;60 y from rural regions of Cuba, Chile and Mexico

In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas. The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique. The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico. Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured. Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altman's procedure were used to analyze the data. Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(-7.71+(H(2)/R x 0.49)+(country or ethnicity x 1.12)+(body weight x 0.27)+(sex x 3.49)+(Xc x 0.13)), where H(2) is height(2) (cm); R is resistance (Omega); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Omega). R(2) was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean+/-s.d. of FFM prediction was 44.2+/-9.2 vs 44.6+/-10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was accurate. The intercept (=-0.32) was not significantly different from zero (P=0.89) and the slope (=1.02) not significantly different from 1.0 (P>0.9). The R(2) was 0.86, RMSE=3.86 kg of FFM and the pure error was 3.83. The new BIA equation is accurate, precise and showed good agreement. The use of this equation could improve the estimates of body composition for the elderly population for these regions, as well as enhancing the opportunity to conduct studies in the elderly population from Latin America.

Relationships of resting energy expenditure with body fat distribution and abdominal fatness in Japanese population.

Body fat distribution and abdominal fatness are indicators of risks for coronary heart disease. However, the relationships between resting energy expenditure (REE) and the body fat distribution or the abdominal fatness are unclear. We examined the relationships of REE with whole-body fat distribution (waist, hip and waist-to-hip ratio: WHR) and abdominal fatness (intra-abdominal fat: IF and subcutaneous fat: SF) after adjustment for body composition. 451 men and 471 women were subdivided into two groups, 40-59 years: middle-aged group and 60-79 years: elderly group. REE was measured by an indirect calorimetry system. Percentage of fat mass (%FM), fat mass (FM) and fat-free mass (FFM) were assessed by a dual-energy x-ray absorptiometry method. The IF area (IFA) and SF area (SFA) at the level of the umbilicus were measured using computed tomography. Circumference of waist and hip were measured in a standing position. The WHR, waist circumference and SFA did not significantly (p>0.05) associate with the REE after adjusting for FM, FFM and age in any of the groups. The adjusted REE was significantly and inversely correlated with hip (r=-0.159, p<0.05) and IFA (r=-0.131, p<0.05) in the elderly men. These results suggest that lower REE may contribute to greater hip and IFA rather than WHR and waist in elderly men.

Thermogenesis induced by a high-carbohydrate meal in fasted lean and overweight young men:: insulin, body fat, and sympathetic nervous system involvement

Objective This dietary trial was designed to evaluate the effect of an experimental short-term fasting period followed by a high-carbohydrate meal on energy expenditure, thermogenesis, and sympathetic nervous system activity in normal (body mass index < 25 kg/m 2) and overweight (body mass index > 27 kg/m 2) men who were healthy, non-diabetic or with no other endocrine disease, non-smokers, not taking oral prescription medications, and with a stable body weight for the previous 3 mo. Methods Fasting and fed energy expenditures and diet-induced thermogenesis were measured after a high-carbohydrate meal in seven overweight and six lean young male subjects by indirect calorimetry. Heart rate, urinary excretion of catecholamines, serum glucose, and insulin were also measured over the experimental fasting (7.5 h) and postprandial (4 h) periods. Results After carbohydrate intake, overweight men showed a significantly higher energy production (kJ/kg of fat-free mass) than did lean individuals, and the diet-induced thermogenesis (percentage of energy intake) was positively correlated with body fat (kg), percentage of body fat, fat-free mass (kg), and fasting pre-meal serum insulin levels. Postprandial cumulative energy expenditure was directly associated with postprandial insulin response and with mean postprandial heart rate values. No significant differences in urinary catecholamines were found between lean and overweight men at basal conditions or during the study period. Conclusions Overweight individuals showed similar short-term sympathetic nervous system responses induced by an experimental fasting period. Although diet-induced thermogenesis after carbohydrate intake was not statistically different between lean and overweight men, the postprandial insulin response and body fat content seemed to be involved in sympathetic nervous system activity.

Body composition in ambulatory women with multiple sclerosis

Lambert CP, Archer RL, Evans WJ. Body composition in ambulatory women with multiple sclerosis. Arch Phys Med Rehabil 2002;83:1559-61. Objective: To compare whole-body fat mass and fat-free mass (FFM) in ambulatory patients with multiple sclerosis (MS) and control subjects without MS. Design: Nonrandomized controlled trial or cross-sectional study. Setting: An exercise physiology laboratory at a medical school. Participants: Seventeen ambulatory patients with MS and 12 control subjects (all subjects were women). The median Expanded Disability Status Scale (EDSS) score was 4.0 for the individuals with MS. Interventions: Not applicable. Main Outcome Measures: Whole-body percentage of fat-free mass (%FFM), percentage of body fat (%BF), FFM, and fat mass. Results: A significant difference in age was observed between the groups; thus, age was used as a covariate in the body composition analyses. No significant differences were observed between the groups in %BF: 32.5±13.9 and 27.8±5.6 (P=.54) for MS and controls, respectively, or %FFM, 67.1±14.9 and 71.3±12.4 (P=.42) for MS and controls, respectively. For individuals with MS, no significant relation was observed between EDSS score and %BF (P=.24) or between EDSS score and %FFM (P=.24). Conclusion: No significant differences were observed in body composition between ambulatory MS patients and controls. Furthermore, the EDSS score was not a significant predictor of %BF or %FFM for people with MS. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation