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PubMed1983

Effects of caloric restriction on body composition and total body nitrogen as measured by neutron activation.

The purpose of this study was to compare the effects of two isocaloric diets (800 Kcals) on the changes in body composition during weight reduction. While the protein content of both diets was 70 g, the carbohydrate content of diet A was 10 g and that of diet B was 70 g. The various parameters of body composition were determined as follows: Total body potassium (TBK) by 40K counting, total body water (TBW) by the tritiated water technique, total body nitrogen (TBN) by prompt gamma neutron activation analysis (PGNAA) and total body fat was estimated by measuring the skinfold thickness. Routine serum chemistries were performed every 2 wk and serum insulin and triiodothyronine by radioimmunoassay were done at 4-wk intervals. Seventeen obese women who were at least 30% above ideal body weight volunteered for the outpatient study, (group A--10 subjects, group B--7 subjects). At the end of the 12 wk study, the percent changes in the above parameters of body composition were not significantly different for the two groups. The biochemical changes were consistent with the degree of caloric restriction. We conclude that: (1) the technique of prompt gamma neutron activation analysis can be used effectively to determine long term changes in total body nitrogen during weight reduction, (2) loss of lean tissue (water, potassium and nitrogen) as well as fat tissue occurred during weight reduction. The loss of TBN in absolute quantities was less for diet A compared to diet B; however, there was no significant difference between the two diets when the data was expressed as a percent change from the baseline values, and (3) TBK determination probably provides the best estimate of total body fat.

Adult↗
PubMed1997

Alterations in growth and body composition during puberty. I. Comparing multicompartment body composition models.

A four-compartment (4C) model of body composition was used as a criterion to determine the accuracy of three-compartment (3C) and two-compartment (2C) models to estimate percent body fat (%BF) in prepubertal and pubertal boys (genital I & II, n = 17; genital III & IV, n = 7) and girls (breast I & II, n = 8; breast III & IV, n = 15). The 3C water-density (3C-H2O) and 3C mineral-density models, dual-energy X-ray absorptiometry, the Lohman age-adjusted equations, the Slaughter et al. skinfold equations, and the Houtkooper et al. and Boileau bioelectrical impedance equations were evaluated. Agreement with the 4C model increased with the number of compartments (i.e., body water, bone mineral) measured. Except for the 3C-H2O model, the limits of agreement were large and did not perform well for individuals. The mean %BF by dual-energy X-ray absorptiometry (23.6%) was greater than that of the criterion 4C method (21.7%). For the field methods, the Slaughter et al. skinfold equations performed better than did the Houtkooper et al. and Boileau bioimpedance equations. The hydration of the fat-free mass decreased (genital I & II = 75.7%, genital III & IV = 74.8%, breast I & II = 75.5%, breast III & IV = 74.4%) and the mineral content increased (genital I & II = 4.9%, genital III & IV = 5.0%, breast I & II = 5.1%, breast III & IV = 5.7%) with maturation. The density of the fat-free mass also increased (genital I & II = 1.084 g/ml, genital III & IV = 1.087 g/ml, breast I & II = 1.086 g/ml, breast III & IV = 1.091 g/ml) with maturation. All of the models reduced the %BF overprediction of the Siri 2C model, but only the 4C and 3C-H2O models should be used as criterion methods for body composition validation in children and adolescents.

Adipose Tissue↗
PubMed2001

Body composition characteristics and body fat distribution in lean women with polycystic ovary syndrome.

Body composition, fat distribution and bone mineral density were examined in lean women suffering from polycystic ovary syndrome (PCOS) and compared with body composition and fat distribution characteristics of weight-matched lean controls. Ten women with PCOS and a body mass index (BMI) below 25.00 (kg/m(2)) and 10 healthy women with a BMI below 25.00 (kg/m(2)) matched for age and weight and BMI as controls were enrolled in this study. Body composition and bone density were measured by dual-energy- x-ray-absorptiometry and fat distribution patterns were calculated. Although matched for age, weight and BMI, lean PCOS patients showed a significantly higher amount of body fat and lower amount of lean body mass than the controls. The majority of PCOS patients showed an intermediate or android kind of fat distribution. Only 30% of the lean PCOS patients corresponded to the definition of gynoid fat distribution while this was true of all lean controls.

Absorptiometry, Photon↗
PubMed1998

Alterations in growth and body composition during puberty: III. Influence of maturation, gender, body composition, fat distribution, aerobic fitness, and energy expenditure on nocturnal growth hormone release.

We examined the relationships among gender, sexual maturation, four-compartment model estimates of body composition, body fat distribution (magnetic resonance imaging for abdominal visceral fat and anthropometrics), aerobic fitness, basal and total energy expenditure, and overnight GH release in an ultrasensitive chemiluminescence assay in healthy prepubertal and pubertal boys (n = 18 and 11, respectively) and girls (n = 12 and 18, respectively). Blood samples were withdrawn every 10 min from 1800-0600 h to determine the area under the serum GH-time curve (AUC), sum of the GH peak heights (sigma GH peak heights), and the mean nadir GH concentration. GH release was greater in the pubertal than prepubertal subjects due to an increase in sigma GH peak heights (43.8 +/- 3.6 vs. 24.1 +/- 3.5 ng.mL-1, P = 0.0002) and mean nadir (1.7 +/- 0.2 vs. 0.7 +/- 0.2 ng.mL-1, P = 0.0002), but not peak number (4.3 +/- 0.2 vs. 4.5 +/- 0.2). The girls had a greater sigma GH peak heights (39.0 +/- 3.5 vs. 28.8 +/- 3.6 ng.mL-1, P = 0.05) and mean nadir concentration (1.4 +/- 0.2 vs. 0.9 +/- 0.2 ng.mL-1, P = 0.05) than the boys. Significant inverse relationships existed between sigma GH peak heights (r = -0.35, P = 0.06) or mean nadir (r = -0.39, P = 0.04) and four-compartment percent body fat for all boys but not for all girls or when combining all subjects. For all girls, significant inverse relationships existed between sigma GH peak heights (r = -0.39, P = 0.03) or mean nadir (r = -0.37, P = 0.04) and waist/hip ratio. Similar inverse relationships in all boys or all subjects were not significant. Forward stepwise regression analysis determined that bone age (i.e. maturation, primary factor) and gender were the significant predictors of AUC, sigma GH peak heights, and mean nadir. The influence of maturation reflects rising sex steroid concentrations, and the gender differences appear to be because of differences in estradiol concentrations rather than to body composition or body fat distribution.

Adipose Tissue↗
PubMed1985

Basal metabolism of obese adolescents: age, gender and body composition effects.

Body composition (percent fat and lean body mass) and basal metabolic rates were determined in 67 obese adolescents ranging in age from 10 to 16 years (30 male, 37 female). Basal oxygen uptake was determined on rising in the morning using open-circuit spirometry with a 10-min collection period. Body composition was determined from body density measurements using the underwater weighing procedure. There were no male-female differences (except for basal VCO2 production, P less than 0.05) for any body composition or metabolic variable. The subjects' (male and female) average weight was 73 kg, height--157 cm, percent fat--40 percent, fat weight--30 kg, lean body mass--92 kg, and kcal/24 h--1535. Correlations between age, body composition and basal energy expenditure were all moderate to low (r less than or equal to 0.78). In contrast to adult data, lean body mass was not highly correlated to basal energy expenditure suggesting that perhaps there is a 'metabolic condition' of the obese adolescent modulated by excess fatness or the instability of the body cell mass. Stepwise multiple linear regression revealed that for the obese male adolescent, body surface area and percent fat, and for the obese female adolescent body surface area and body weight resulted in the best prediction of basal kcal/24 h. The standard errors of prediction were +/- 17.9 percent for the males, and +/- 14.4 percent for the females.

Adolescent↗
PubMed2001

Effect of energy source and xylanase addition on energy metabolism, performance, chemical body composition and total body electrical conductivity (TOBEC) of broilers.

Three diets containing either no supplemented fat (LF), 12% soybean oil (SO) or 12% coconut oil (CO) were fed to broilers to examine energy utilization in two experiments. Heat production and energy retained as fat and protein were measured in the first experiment using a respiration technique in combination with C- and N-balance and controlled (pair-fed) feeding conditions. Growth performance, carcass composition, chemical body composition and total body electrical conductivity (TOBEC) were evaluated in a second experiment under ad libitum feeding conditions (from hatching to day 35). Moreover, each of the three diet types was tested with or without the addition of a xylanase-containing enzyme preparation in the growth experiment. Energy utilization (experiment 1), expressed as the ratio between total retained energy and metabolizable energy intake, amounted to 0.33, 0.36 and 0.39 in LF-, SO- and CO-fed groups, respectively. Applying ad libitum feeding conditions in the second experiment caused a significant reduction in feed intake and weight gain in broilers fed the CO-diet. The feed-to-gain ratio was significantly lower in birds given the fat-supplemented diets. The highest degree of fatness as indicated by the highest percentage of abdominal and visceral fat and by highest total fat content was found in birds fed the CO-diet. The higher the body protein content and the lower the body fat content, the higher the TOBEC value should be. This was confirmed when LF-fed broilers were compared to their CO-fed counterparts. However, fat type seemed to be related to TOBEC values since SO-fed broilers had similar TOBEC values as CO-fed birds, whereas chemical body composition was comparable to LF-fed broilers. Xylanase addition significantly increased weight gain up to 21 days of age and decreased the feed-to-gain ratio slightly, whereas none of the other parameters were influenced by this treatment. An interaction between energy source and enzyme supplementation was not observed. It is concluded that feeding of coconut oil was most effective in terms of energy retention, but failed to induce an adequate performance under ad libitum feeding conditions due to a reduced voluntary feed intake. TOBEC measurements in relation to chemical body composition were rather inconclusive.

Animals↗
PubMed1983

Body composition of adolescent males. Part I. Total body water in normal adolescent males. Part II. Body composition of the male reference adolescent.

This study was undertaken to obtain total body water (TBW) data suitable for derivation of body composition of the typical adolescent male. TBW by the deuterium dilution method, stage of sexual development and anthropometric parameters (weight, height and triceps and subscapular skinfold thickness) were determined in 108 males between 10 and 14 years of age, whose weight and height fell between the 10th and the 90th percentile of the NCHS reference data. TBW/weight did not change significantly between 10 and 14 years, although a slight increase after age 11 years and from genital stage 2 to stage 5 was present. This indicates that body fat content decreases after 11 years and after genital stage 2, especially if the fact is taken into account that water content of fat-free body mass decreases during this age period. The ability of single anthropometric parameters to predict TBW/weight was low (subscapular skinfold thickness, r = -0.62; triceps skinfold thickness, r = -0.54; weight/height cube ratio, r = -0.48). Even with the use of various combinations of anthropometric parameters in multiple stepwise prediction equations it was not possible to explain more than 50% of the variation of TBW/weight and the high standard error of the estimate indicated large errors in prediction. Thus, body composition of normal adolescent males cannot be predicted with an acceptable degree of accuracy by anthropometric parameters. On the other hand, the deuterium dilution method using salivary water represents a noninvasive method for the determination of TBW which is quite simple and suitable for field studies.

Adolescent↗
PubMed2006

Body composition, weight status, body image and weight control practices among female adolescents from eastern Austria.

The prevalence rates of obesity, but also of altered eating behaviour up to clinically manifested eating disorders have increased dramatically during the last years. In the present study the weight status, body composition and eating behaviour as well as weight controlling strategies of 1752 female adolescents ageing between 12 and 18 years (x=14.6) from Eastern Austria were documented. Furthermore, data regarding socioeconomic status and educational level of the probands were collected. It could be shown, that a higher educational level or a higher socioeconomic status was associated with a significantly lower fat percentage and a significantly lower prevalence of overweight and obesity. Underweight and severe underweight was predominantly found among girls ageing between 15 and 18 years of higher educational level. Weight controlling behaviour such as stepping on scale and altered or restricted eating behaviour was widespread among the probands, independent of weight status and socioeconomic parameters. Body weight and shape concerns were also found very frequently independent of educational level. The results of the present study corroborate the findings of former investigations, that disturbed eating behaviour and concerns regarding body weight and shape are found among all socioeconomic groups.

Adolescent↗
PubMed1985

Body composition in elderly people. I. Determination of body composition by multiisotope method and the elimination kinetics of these isotopes in healthy elderly subjects.

The body composition of 40 healthy elderly and 20 healthy young subjects was determined and compared. It was found that the age-related changes were more marked in females than in males. Total body water was decreased as a consequence of diminished lean body mass. Extracellular fluid volume remained unchanged, while plasma volume increased. Thus, the liquid components of lean body mass were redistributed between the intracellular and extracellular spaces. The elimination kinetics of isotopes were not significantly different between young and aged subjects, except the elimination of radiosulfate.

Aged↗
PubMed1969

Effects of weight changes produced by exercise, food restriction, or overeating on body composition.

The body weight of rats was reduced by exercise or by restriction of food intake over a period of 18 wk. Body composition was studied to determine if exercise protects against the loss of lean tissue that can occur as a result of a negative caloric balance. Rats weighing 706 +/-14 g were divided into four groups matched for weight. A baseline group was killed at the beginning of the study. An exercising group, fed ad lib., was subjected to a program of swimming. A sedentary, free-eating group was provided with food ad lib. Two sedentary, paired-weight subgroups were calorie restricted so that they lost weight at the same rate as the exercisers. The protein intake of one paired-weight subgroup was matched with that of the exercising group. The other sedentary, paired-weight animals ate the standard diet. There was no significant difference in body composition between the two sedentary, paired-weight subgroups which were, therefore, pooled for comparison with the other groups. The exercisers lost 182+/-19 g as a result of both an increase in caloric expenditure and a decrease in appetite. The sedentary, food-restricted animals lost an average of 182+/-18 g. The sedentary, free-eating animals gained 118+/-13 g. The carcasses of the exercised animals contained significantly less fat and more lean tissue than those of the sedentary, paired-weight animals, providing evidence for a fat mobilizing and protein conserving effect of exercise. The composition of the body substance lost by the exercising animals was 78% fat, 5% protein, 1% minerals, and 16% water, compared to 62% fat, 11% protein, 1% minerals, and 26% water for the sedentary, food-restricted rats. Fat accounted for 87% and water for 10% of the weight gained by the sedentary, free-eating animals.

Animals↗
PubMed2002

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

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

Adipose Tissue↗
PubMed2001

Childhood body composition in relation to body mass index.

OBJECTIVE: The aim is to describe body composition in relation to body mass index (BMI; body weight/stature(2)) to provide health care professionals insight into the meaning, significance, and limitations of BMI as an index of adiposity during childhood. METHODS: Data from 387 healthy, white children 8 to 18 years of age from the Fels Longitudinal Study were analyzed. Measurements were scheduled annually and each child was examined 1 to 11 times, totaling 1748 observations. Total body fat (TBF) and fat-free mass (FFM) were determined from hydrodensitometry. Stature and weight were measured using standard methods and BMI and the components of BMI, TBF/stature(2), and FFM/stature(2) were calculated. Analyses included correlations between BMI and body composition variables; age-related patterns of BMI, TBF/stature(2), and FFM/stature(2); and annual changes in BMI, TBF/stature(2), and FFM/stature(2). RESULTS: Generally, correlations between BMI and body composition variables were strong and significantly different from zero. Means for BMI throughout childhood were similar for boys and girls, although significantly larger values were observed for girls at ages 12 to 13 years. Age-related patterns of TBF/stature(2) and FFM/stature(2) differed between sexes. In each sex, annual increases in BMI were driven primarily by increases in FFM/stature(2) until late adolescence, with increases in TBF/stature(2) contributing to a larger proportion of the BMI increases in girls than in boys. CONCLUSIONS: Unlike adults, annual increases in BMI during childhood are generally attributed to the lean rather than to the fat component of BMI. Because the properties of BMI vary during childhood, health care professionals must consider factors such as age and sex when interpreting BMI.

Adipose Tissue↗
PubMed2003

[Bone mineral and body composition analysis of whole body in 292 normal subjects assessed by dual X-ray absorptiometry].

OBJECTIVE: To understand whole body bone mineral and body composition changes in normal subjects, and study the relationship between body composition and bone mineral. METHODS: 292 normal subjects aged 10-79 years old, including 140 males and 152 females, were selected to be measured bone mineral content (BMC), bone mineral density (BMD) lean and fat of whole body by dual X-ray absorptiometry (DXA). Individuals were divided into age-groups by every ten years and were analyzed by statistical methods. RESULTS: In males, peak values of BMC, BMD, lean and fat were in the 30-39, 20-39, 30-39, 70-79 age-groups. In females, they were in the 30-39, 30-39, 30-49, 50-69 age-groups respectively. Peak values of BMC, BMD and lean were higher in males than that in females, but peak value of BMD was not significantly higher in males than that in females. Peak value of fat was higher in females than that in males. Loss of BMC and BMD for females were more pronounced than that for males. Loss of lean for males was more pronounced than that for females. There are significant positive correlation between lean, weight and bone mineral in males and females. Fat has significant effect on BMC in females only. CONCLUSIONS: The normal bone mineral and body composition data of whole body for males and females, and the characteristic of changes with aging are provided for analyzing the relationship between bone mineral and body composition with ease.

Absorptiometry, Photon↗
PubMed1996

Exogenous androgens influence body composition and regional body fat distribution in obese postmenopausal women--a clinical research center study.

Abdominal fat distribution is influenced by androgen levels in both men and women. The purpose of this study was to assess the effects on fat distribution of administering nandrolone decanoate (ND; an anabolic steroid with weak androgenic activity) or spironolactone (SP; an antiandrogen) in obese postmenopausal women. The design was a randomized, placebo-controlled, 9-month trial with simultaneous calorie restriction for weight loss. Women in all three groups lost comparable amounts of weight, but the ND-treated women gained lean mass relative to the other two groups (P < 0.0005) and lost more body fat than women in the SP group (P < 0.01). The resting metabolic rate also increased slightly in the ND group. ND treatment produced a gain in visceral fat, as determined by computed tomography scan, and a relatively greater loss of sc abdominal fat. SP-treated women lost significantly less sc fat than the other two groups. Serum cholesterol decreased in the placebo group, but increased slightly in the other two groups (significant for SP vs. placebo, P < 0.05). High density lipoprotein cholesterol decreased significantly in the ND-treated women. There were no significant changes in fasting glucose or insulin sensitivity. We conclude that administration of exogenous androgens modulates body composition in obese postmenopausal women and independently affects visceral and sc abdominal fat.

Adipose Tissue↗
PubMed1996

Comparison of body composition by dual energy X-ray absorptiometry to other estimates of body composition during weight loss in obese patients with rheumatoid arthritis.

Body composition was determined by dual energy X-ray absorptiometry (DXA) scanning and classical reference methods (40K, 3H2O, and a combination of these in a four-compartment model) in 19 overweight patients with rheumatoid arthritis who underwent a 12-week weight-reducing regimen. The aim of the study was to investigate whether DXA provides a valid estimate of body composition. The results showed that weight as determined by DXA was highly significantly correlated to weight determined by scales. Furthermore, significant correlations were found in the body components (fat-free mass, fat mass) determined by DXA, 40K, 3H2O and the four-compartment model. Mean values differed slightly but significantly. With respect to changes in body composition, no significant correlations were found between any of the methods, except for the weight loss recorded by DXA and scales, and loss of fat mass (and fat free mass) estimated by 3H2O and the four-compartment model. The sparseness of correlations reflected the small changes in fat-free mass and fat mass (2.6 and 1.7 kg respectively), and the fact that changes were comparable to measurement errors of the various methods. We suggest that DXA scanning is a valid supplement for determination of body composition. Validation of DXA scanning requires new experimental in vitro investigations, which, incidentally, also applies to the classical reference methods.

Absorptiometry, Photon↗
PubMed1980

Body composition. Prediction of normal body potassium, body water and body fat in adults on the basis of body height, body weight and age.

In 134 males and 242 females, aged 20-70 years, most of them randomly selected from population studies, the body composition was estimated from the measurements of body height (BH), body weight (BW), total body potassium (TBK) and total body water (TBW). TBK was measured with isotope dilution technique using 42K or determined as 40K in a whole body counter. TBW was determined with an isotope dilution technique using tritiated water, assayed in urine or plasma. From these data, body cell mass (BCM), intra- and extra-cellular water (ICW and ECW, resp.) and body fat (BF) were calculated for each individual. Significant correlations were found between age versus TBK, ECW, BF and ECW/ICW; between BW versus TBK, TBW, ECW, BF and ECW/ICW; (females only) and between BH versus TBK, TBW, ECW (females only) and ECW/ICW. For the prediction of TBK, TBW and BF, multiple regression equations based on BW, BH and age are given. These equations are also presented diagrammatically. The problems with the methods used are considered as well as the applicability of the formulas for the calculation of BCM etc. The predictive value of the results when both TBW and TBK are used for the calculation of body composition data is discussed and compared with similar results, based on TBW or TBK only. It is concluded, that the most reliable method for calculation of BF is to estimate both TBW and TBK.

Adult↗