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Body composition in myelomeningocele.

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.

Adipose Tissue↗

Estimation of body composition from bioelectric impedance of body segments.

The hypothesis that body composition can be estimated accurately from measurements of the length and resistance of the body segments was tested. Weight; stature; whole-body resistance; and the resistances, lengths, and circumferences of the leg, trunk, and arm were measured for 135 white men and women aged 18-58 y. Fat-free mass (FFM) and percent body fat (%BF) were obtained from densitometry. The resistance of the whole body was determined almost entirely by the resistances of the arm and the leg. The accuracy of the prediction of FFM from arm length2/arm resistance and of %BF from weight x arm resistance/arm length2 was only marginally less than that obtained by using whole-body measurements. Thus, measurements of the resistance and length of the arm can be used in place of the whole-body methods for estimating body composition from bioelectric impedance.

Adipose Tissue↗

Appetite and the regulation of body composition.

Stability of body composition requires that energy intake equals energy expenditure when integrated over prolonged periods. As recent human studies have failed to demonstrate active changes in energy expenditure with changes in body composition, it is likely that energy intake is continually adjusted to preserve a constant total adipose tissue mass. If adipose tissue mass is regulated directly, then there must be some input reflecting this quantity to the central nervous system for the purpose of making corrective changes in appetite when total body fat content fluctuates. The nature of this input has been examined in a variety of animal experiments involving induced weight change, lipectomy, plasma transfer from obese or satiated animals to hungry animals, and parabiosis between obese and lean animals. The bulk of evidence suggests that the plasma level of one or more currently unidentified stable circulating molecules increases in proportion to total body fat content and augments the effect of meal-related satiety signals in the central nervous system. The implications of this adipose tissue-related satiety factor for the pathogenesis of obesity, and the possible nature of the factor are discussed.

Animals↗

Deficiency of the growth hormone-insulin-like growth factor-I axis potentially involved in age-related alterations in body composition.

Because the body composition effects of growth hormone and insulin-like growth factor-I (IGF-I) are opposite to those of advancing age, it has been hypothesized that the decreased activity of the growth hormone-IGF-I axis is partly responsible for the loss of bone and muscle mass that characterizes normal human aging. The aim of the present cross-sectional analysis was to test this hypothesis in a well-defined community-based sample of 245 healthy elderly women. Dual-energy X-ray absorptiometry was used to measure body composition. To establish the major determinants of total bone mineral content (TBBMC), we assessed the relationships between TBBMC and age, height, weight, body mass index, muscle strength and serum concentrations of IGF-I, calcidiol, calcitriol, parathyroid hormone and sex hormone-binding globulin. Total body lean mass (TBLM), an indication of muscle mass, was related to the following potential determinants: age, habitual physical activity and serum IGF-I. Multiple regression was used to adjust for potential confounders. A significant relationship between circulating IGF-I and TBLM was not apparent in this study. On the other hand, serum IGF-I was found to be an independent predictor of TBBMC, despite the inclusion of established determinants of bone mass. These findings suggest that the demineralization of the skeleton in aging women is in part due to a deficiency of the somatotrophic axis.

Absorptiometry, Photon↗

Body composition estimations by BIA versus anthropometric equations in body builders and other power athletes.

BACKGROUND: Two main questions are stated: 1) are BIA and anthropometric equations accurate in estimating body composition in male power athletes and more specifically in body builders and 2) is there a difference in body composition when body builders are compared to weight and power lifters? METHODS EXPERIMENTAL DESIGN: this is a descriptive, comparative study on a selected sample of power athletes. PARTICIPANTS: 49 Belgian elite and sub-top male power athletes (34 body builders and 15 weight and power lifters) were included in this sample. More than 70% was in preparation of competition at time of data collection. MEASURES: an extended set of anthropometric measures was taken. Body composition was estimated by BIA (Bioelectrical Impedance Analysis) and by regression equations of skinfolds. Somatotype and muscle+bone areas were calculated. Factor analysis on all anthropometric measures was carried out to determine the body structure of the athletes. RESULTS: Compared to external visual criteria, the equations of Durnin and Womersley and Lohman (skinfolds) and the Guo-equation (BIA) were the only equations that could accurately estimate the body composition for this specific group of athletes. However, the sum of skinfolds attains the most accurate estimate of subcutaneous fatness. Body builders have significantly (p<0.01) larger arm and thigh circumferences and are more mesomorfic than the other power athletes (5.9 vs 3.8). CONCLUSIONS: This study shows that to estimate body composition in extreme power athletes BIA is not as accurate as compared to anthropometric equations. Moreover, the sum of a larger set of skinfolds is preferred to anthropometric prediction equations. In addition, body builders are more muscular and leaner than other power athletes.

Adipose Tissue↗

[Non-invasive measurement of body composition].

The concept of body composition covers the division of the body into a number of compartments. The most important are the fat mass (FM), the fat-free mass (FFM), the total body protein and the total body bone mineral content. Numerous methods for the measurement of body composition are available. The three classical methods for the measurement of FM and FFM, namely underwater weighing, measurement of total body potassium and measurement of total body water by isotope dilution, are often regarded as reference methods. However, newer methods such as computed tomography, neutron activation analysis and dual energy X-ray absorptiometry are increasingly used because of their reliability and ability for independent measurement of two or more components. Bioelectrical impedance analysis has become popular because of its clinical applicability. Three- or four-compartment models involving combination of two, three or more separate methods are more accurate than single methods, but are usually confined to research purposes because of the laborious measurement procedures. Computed tomography and dual energy X-ray absorptiometry have the unique possibility of regional measurements of body composition. Fat distribution and relative overweight may be estimated by simple anthropometric measures such as skinfold thicknesses. There are many applications for body composition measurements in research and clinical practice. These include treatment of obesity, growth hormone deficiency, diabetes mellitus and climacteric changes, as well as clinical nutrition and estimation of the hydration of dialysis patients and of critically ill intensive or surgical patients.

Body Composition↗

Estimation of neonatal body composition: isotope dilution versus total-body electrical conductivity.

The objective of the study is to evaluate neonatal body composition determined by the isotope dilution method compared with the total-body electrical conductivity (TOBEC) method. An oral dose of 18O- and 2H-labeled water was given to 40 healthy term newborns, and 26 infants successfully completed the protocol. The isotope concentrations in urine samples were measured by gas-isotope ratio mass spectrometry. Fat and percent body fat (%F) estimated by isotope dilution were correlated with fat and %F estimated. Total body water measured by isotope dilution of 18O and 2H was 2.44 +/- 0.36 and 2.49 +/- 0.35 kg, respectively (p < 0.001). Fat and %F estimated by 18O, 2H, and TOBEC were 0.48 +/- 0.20 kg and 13.7 +/- 5.1%, 0.48 +/- 0.19 kg and 13.7 +/- 4.6%, and 0.38 +/- 0.21 kg and 10.9 +/- 5.0%, respectively. Neither fat nor %F estimates by isotope dilution showed good correlation with the TOBEC estimates (r = 0.22-0.57). Because of the wide variation of water content in individuals, the isotope dilution method may not be the optimal way of assessing body composition, and specifically body fat, in newborns.

Adipose Tissue↗

Low- and high-carbohydrate diets: body composition differences in rats.

OBJECTIVE: To determine differences in adipose tissue mass, cell size, and lipid metabolism transcripts and differences in composition of body weight loss and energy expenditure (EE) after isoenergetic, energy-restricted intake of low-carbohydrate/high-fat/high-protein (LC) and high-carbohydrate/low-fat/moderate-protein (HC) diets. RESEARCH METHODS AND PROCEDURES: Ten-week old female Sprague-Dawley rats were fed a high-fat diet ad libitum for 8 weeks to induce weight gain and fat deposition. Weight-matched rats were then assigned to isoenergetic LC (Atkins) and HC (American Dietary Association Exchange) diets for 10 weeks at 65% of ad libitum energy intake. RESULTS: There was no significant difference in the serum lipid profiles or amount of body weight lost between the HC and LC groups, whereas a higher insulin sensitivity index (p < 0.01) resulted from the HC compared with the LC diet. Compared with the post-restriction LC group, the HC group demonstrated (p < 0.05) higher EE during active hours, lower mRNA levels for the lipogenic genes peroxisome proliferator-activated receptor gamma2, lipoprotein lipase, and, adipocyte fatty acid binding protein, decreased adipocyte cell volume, and decreased fat mass. DISCUSSION: Results indicated down-regulation of lipogenic genes, decreased fat mass, and, therefore, improved body composition in the post-restriction HC compared with the LC group. The small mean differences between the two diet groups (p = 0.11) in 24-hour EE over the 10 weeks of diet intervention would account for the majority of the lower mean body weights in the post-restriction HC group. These data suggest that macronutrient composition of the diet influences body composition and indicate a distinction between HC and LC diets.

Animals↗

Comparison of different body composition models in acromegaly.

The aberrant body composition of 10 patients with active acromegaly was used to evaluate the validity and limitations of several models and methods to assess body composition. Body composition was determined using either a two-compartment model, dividing the body in a body fat (BF) compartment and a fat-free mass (FFM) compartment, or a four-compartment model in which the FFM compartment comprises the three following components: body cell mass, extracellular water and the fat-free extracellular solids. The measurement techniques consisted of anthropometry, bioelectrical impedance analysis (BIA)-applying various established regression equations-tritiated water dilution, whole body 40K-counting, and whole body computed tomography (CT). This latter method was used as the reference technique. Assessment of total body water using BIA - applying the RJL or Kushner equation-correlated significantly with the assessment using tritiated water dilution (P < 0.01). Body fat assessment using the two-compartment model based on either tritiated water dilution or BIA-applying the RJL or Lukaski equation-as well as body fat assessment using the four-compartment model based on tritiated water dilution and whole body 40K-counting were significantly correlated with body fat assessment using CT (P < 0.01) and resulted in good agreement with each other with respect to the absolute values of the body fat determination. BIA using other regression equations overestimated body fat by 7.2-13.7 kg. Whole body 40K-counting was significantly correlated with CT-determined muscle plus skin volume (P < 0.001). CT-calibrated anthropometric predictions significantly overestimated body fat. It is concluded that in patients with active acromegaly, the determination of body composition using either certain two-compartment models based on measurement of total body water or bioelectrical impedance, or a four-compartment model based on total body water and total body potassium measurements show good agreement with CT-determined body composition.

Acromegaly↗

[Estimation of body composition based on total body water determination using phenazone for assessment of body fat gain in cattle. 2. Relationship between body fat content and back fat thickness].

Back fat thickness was measured at six points in 251 beef heifers aged 3 to 17 months, in 27 beef bulls aged 15 months and in 200 Holstein dairy cows of different age. This was paralleled by estimation of body fat content based on total body water analysis. All groups of animals showed the same pattern of back fat thickness for the measuring points investigated, which lead to the result of one optimum measuring point for determination of back fat thickness. The correlation coefficients between back fat thickness and body fat content were estimated to be between 0.80 and 0.87 for all groups investigated. Change in back fat thickness by 1 mm corresponded to gain or loss of around 5 kg body fat in all animal groups. Therefore it is possible to make concrete assessments of body fat content on the basis of back fat thickness.

Adipose Tissue↗

[Realization of a new segmental bioelectrical impedance method for assessing body composition: correlation analysis of human body parameters].

The method of segmental bioelectrical impedance analysis for assessing body composition requires measurement of segmental lengths and cross-sectional areas; thus its complexity is increased. This paper reports the correlation analysis of human body parameters and the linear regressions for predicting segmental parameters by use of gender, height and weight. Accordingly, segmental impedance analysis is simplified.

Adolescent↗

Body composition measurements.

Measurement of body composition is an important tool for the assessment of nutritional status. During the past decades, new methods have been developed for the quantification of body fat. The model commonly used in body composition research is the two-component model. The two components are the fat and the fat-free mass, both with a specific density; the sum of the two components is the body mass. The fat-free mass is not homogeneous, but theoretically consists of several "fat-free" organs, tissues and fluids. Yet, the two-component model is often used because it is difficult to obtain detailed information about the relative proportions of organs, tissues and fluids. Body composition studies are based on quantitative measurements of one of the components of the human body. A review of measuring techniques, each with a specific approach to analysis of body composition, is presented.

Anthropometry↗

Body composition, eating behavior, food-body concerns and eating disorders in adolescent girls.

AIMS: Dieting is a behavioral phenomenon which is becoming more frequent among adolescents and the search for weight loss, through dieting, may result in an unbalanced nutrition both quantitatively and qualitatively. Our study intended to look at the eating habits and behavior on a cohort of adolescent girls to verify the presence of unbalanced diets and the prevalence of eating disorders with particular attention to the partial syndromes (EDNOS). METHODS: A cross-sectional double-stage study was carried out on a group of schoolgirls in the suburbs of Naples. We assessed anthropometrical measures, body composition (skinfolds and bioimpedance analysis), dietary intake by means of 3-day food records and we administered the Eating Disorder Inventory 2 and Psychosocial Factor Risk Questionnaire. A multidisciplinary and double-stage approach had been used to get a better diagnosis of eating disorders in our sample. RESULTS: 156 adolescent girls, 14-18 years old, took part in our study. Height, weight, and BMI were 160.38 cm, 58 kg and 22.6, respectively. Analysis of food intake showed that all the values reported, with the exception of lipids and sodium, were below the recommendations by LARN. We observed a prevalence of 1.28% of bulimia nervosa, 1.28% of binge eating, and 10.25% of eating disorders not otherwise specified. EDI 2 and PRFQ confirmed how important drive for thinness and body dissatisfaction dimensions are when we deal with adolescent girls and with the phenomenon of dieting. The study confirmed the validity of the PRFQ questionnaire to evaluate mass media influence on body perception and eating behavior of adolescents. CONCLUSION: Multidisciplinary and well-designed studies are needed to systematically and accurately study eating habits and behavior of adolescents to tackle more efficiently the increasing spread of eating disorders and obesity.

Adolescent↗