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PubMedDate not supplied

Effect of a low-Fat diet on body composition and blubber fatty acids of captive juvenile harp seals (Phoca groenlandica).

We investigated the effects of a change from a high-fat diet to a low-fat diet of differing fatty acid (FA) composition on the body composition and blubber FA of five captive juvenile harp seals. Seals that had been maintained for 1 yr on a diet of Atlantic herring (>/=9% fat) were switched to a diet of Atlantic pollock (1. 7% fat) for 30 d. On days 0, 14, and 30, mass and body composition (using isotope dilution) were measured, and blubber biopsies (5 cmx6 mm) were taken for FA analysis. Fat accounted for 38%-49% of body mass at the start of the experiment. When switched to the pollock diet, and despite food intakes averaging 6.5 kg/d (32.3 MJ/d), body fat declined by an average of 6.4 kg or by 32% over the 30-d experiment. In contrast, body protein increased in direct relation to protein intake (r2=0.836, P=0.030). Despite substantial loss of body fat, blubber FA signature changed significantly to reflect the changes in dietary intake of FA, and the deposition of FA was quantifiably predictable. Our results suggest that young growing phocids are unable to maintain body fat stores on low-fat diets even when protein intakes are high. This may have significant implications for juvenile pinniped survival in the wild. In addition, turnover and deposition of dietary FA in blubber takes place in nonfattening seals.

Adipose Tissue↗

PubMed2000

Precocious puberty and body composition: effects of GnRH analog treatment.

INTRODUCTION: Body composition changes with age and sex differences become significant only after puberty. Boys and girls before the age of 8 yr do not differ in fat, lean or bone mineral mass. Hormonal influences during pubertal development determine the physiological adult male and female body composition phenotype. AIM: The aim of our study was to evaluate body composition changes due to central precocious puberty (PP) and the specific effects of therapy on these modifications. SUBJECTS AND METHODS: Sixteen patients (14 girls, 2 boys) were included in the study. They were diagnosed as affected by idiopathic PP according to standard hormonal and clinical criteria; anatomic alterations of hypothalamus-hypophysis region were excluded by MRI. Mean age at diagnosis was 5.9 +/- 1.9 yr. All patients received GnRH analog (Leuprolide or Triptorelin) treatment subcutaneously every 4 weeks for at least 1 yr. Mean period of treatment was 3.4 +/- 1.9 yr. Standard anthropometry and body composition analysis were performed at baseline and every 6-12 months. A group of healthy subjects with normal timing of puberty was matched (for age or for pubertal stage) served as the control group (CA or CP, respectively). RESULTS: Patients with PP showed at baseline a significant increase of BMI and relative body weight; lean and fat compartments were also increased but not significantly. During treatment, the PP group showed increased fat mass compared to CA (p<0.05), while no difference was found between PP and CP. Lean mass was similar to CA but lower than in CP (p<0.05). During treatment a significant increase in lean mass (both as total as well as limb mass) was observed. After stopping treatment there was no difference between PP and CP, except for lower lean mass (p<0.04). CONCLUSION: When puberty occurs precociously, lean and fat mass are not significantly different from age-matched control subjects. Data collected during treatment confirm a shortening of prepubertal lean mass development and the block of further lean mass development due to puberty itself, while fat mass accumulation continues. The net result of these modifications determines a typical body composition pattern in PP patients, after the end of therapy: lean mass is reduced by a shortening of the prepubertal growing period and by the "menopausal effect" of treatment itself. Fat mass is increased as a consequence of therapy and could lead to future obesity.

Adipose Tissue↗

PubMed1992

Assessment of whole-body composition with dual-energy x-ray absorptiometry.

Dual-energy x-ray absorptiometry (DXA) allows noninvasive direct measurement of the three major components of body composition: lean body mass (LBM), fat body mass (FBM), and bone mineral body mass (BBM). To study the accuracy and short-term and long-term precision of body composition measurements, the authors measured body composition with DXA in 60 healthy young adults. Independent measurement of LBM (LBMK-40), obtained from the determination of the whole-body content of potassium-40 with a whole-body scintillation detector, was highly correlated with LBM determined with DXA (LBMDXA) (LBMK-40 = 1.069.LBMDXA,R2 = .996). Assessment of body composition in 10 patients with acquired immunodeficiency syndrome (AIDS) and 10 patients with cystic fibrosis was performed with DXA. The AIDS patients showed a marked decrease in LBM, while in patients with cystic fibrosis, LBM and BBM were decreased. DXA measurements of body composition appeared accurate and precise enough to be of clinical relevance in detecting specific alterations of body composition.

Absorptiometry, Photon↗

PubMed1996

Comparison of five body-composition methods in peritoneal dialysis patients.

Body-composition assessment is an important method of evaluating nutritional status in peritoneal dialysis patients. Because body-composition measurement estimates have not been fully validated in this population, we assessed five body-composition methods in 30 well-dialyzed peritoneal dialysis patients. The techniques studied included bioelectrical impedance analysis, dual-energy X-ray absorptiometry, total-body potassium counting, and anthropometry by two techniques. The dialysis patients were matched for age, race, sex, height, weight, and body mass index with 29 healthy control subjects in our laboratory database. By 5 x 2 x 2 analysis of variance, significant differences were found between results by modality (P < 0.0001) as well as by sex, with women having an increased percentage of fat (P < 0.0001). However, there was no significant intermethod difference by condition (peritoneal dialysis or control). That is, although significantly different percentage fat values were found between the body-composition techniques, this variability was independent of whether the measurement was made on control or peritoneal dialysis patients. Despite the differences between modalities, all techniques were found to correlate significantly with each other (P < 0.01 or better for men and P < 0.001 or better for women). Our experience shows that these routine techniques for measuring body composition can be readily applied to stable peritoneal dialysis patients.

Absorptiometry, Photon↗

PubMed2002

Establishing body composition in obesity.

The field of human body composition research is reaching a mature stage in its development. Quantifying the main body components is integral to the study of growth, as the assessment of human physical characteristics is important both in anthropological and medical fields. This article will focus on body composition methodology. Specifically, our attention is aimed at estimates of body fatness. An overview is first provided of the five-level model of body composition as it relates to measures of fatness. We then provide general concepts related to techniques for estimating body composition. Finally, we briefly discuss the measurement of adipose tissue distribution.

Absorptiometry, Photon↗

PubMed1984

Research progress in validation of laboratory methods of assessing body composition.

This paper presents various laboratory methods designed to estimate body composition and documents some of the progress in their validation. In addition to the well-known methods of densitometry, hydrometry, and spectrometry (40K), many other methods will be reviewed briefly for their relation to body composition. Emphasis is given to validation principles which need to be followed if new methods are to be developed. The reliance of past research on the two-component model and reference man is reviewed, and the need for multicomponent approaches to the study of body composition is emphasized. Past research using the two-component approach has until recently led to lack of research in developing new methodologies, has limited the potential usefulness of various laboratory methods in estimating body composition in different populations, and has made the relation of body composition to health, performance, and exercise an inexact science. The application of several multicomponent approaches to the characterization of both fat-free body composition and body composition of various populations will lead to the development of reference bodies so essential for the advancement of the field. The estimation of body composition changes with exercise, growth, development, and aging and the relation of body composition to health and physical performance are important areas for future research using various multicomponent approaches.

Adipose Tissue↗

PubMed1977

Estimations of body composition by various methods.

Body composition was measured in 38 young men all of whom were overweight by standard height-weight tables. The techniques used were body volumetry, determination of total body water by tritium dilution, whole body 40K counting, and anthropometric measurements required for an equation by Wright and Wilmore, the biceps-height formula, and a complex anthropometric model. Body volumeter and total body water dilution results agreed closely. 40K counts gave lower means for the lean mass (higher means for fat mass and percent body fat), while the Wright-Wilmore equation and complex anthropometric model gave high mean values for lean mass (low means for fat mass and percent body fat). Among the five methods correlation coefficients ranged from 0.81 to 0.94 for lean body mass, from 0.74 to 0.89 for fat mass, and from 0.60 to 0.86 for percent body fat. Although all subjects were overweight, only six (16%) were obese.

Anthropometry↗

PubMed1991

Changes in body composition with danazol therapy.

Whole body lean and fat mass measurements by dual energy x-ray absorptiometry were performed in 14 premenopausal women undergoing danazol treatment for endometriosis. After 6 months, there was a significant increase in lean tissue mass. Body fat decreased but this was significantly less in the android (upper body segment) region than in the gynoid (lower body segment) region. Danazol thus has both anabolic and androgenic effects on body composition. Dual energy x-ray absorptiometry provides a new, noninvasive, and rapid means of studying body composition.

Adipose Tissue↗

PubMed1985

Selection for different growth parameters in laboratory mice and its correlated effects on body composition and organ weights.

Body composition and organ weights were determined in male mice sampled from 4 different lines of a selection experiment: DU-6P (selected for high protein amount), DU-6 (selected for high body weight), DU-6 + LB (selected for an index combining body weight and endurance fitness) and DU-K (unselected control line). Selection was carried out under the conditions of ad libitum feeding and standardization of litter size at birth. In all 3 selection lines a significant direct selection response was shown. While fat in lines DU-6P and DU-6 + LB remained normal, it increased after selection for body weight (DU-6) significantly. Up to generation 13 the average increase of fat was 0.32% per generation. Investigations on 28 to 80 days old mice showed, that males of this line were fatter before, at and after the age of selection (42 days). After 9 generations the body weight of selected mice was significantly increased by 23 to 29%. The absolute organ weights of hearts, livers and kidneys were also significantly higher, while the relative weights of hearts and kidneys decreased. The relative liver weights were in the selected lines higher, but only the difference DU-6 vs. DU-K was significant.

Animals↗

PubMed1992

Changes in fat-free mass in obese subjects after weight loss: a comparison of body composition measures.

Estimates of body composition by densitometry were made in 84 apparently healthy subjects (42 men, 42 women) with a mean age of 40 +/- 6 years (mean +/- s.d.), before and after weight loss. The initial body mass index (BMI) was 30.7 +/- 2.3 kg/m2 and the achieved weight loss on a 4.2 MJ/day energy deficit diet for 13 weeks was 12.2 +/- 3.7 kg. The results by densitometry were compared with estimates obtained by four other techniques: deuterium oxide dilution, skinfold thickness, bioelectrical impedance (three equations) and BMI (two equations). The fat-free mass (FFM) loss estimated by densitometry in men and women was 2.8 +/- 1.8 kg and 1.3 +/- 1.3 kg respectively. The dilution technique gave comparable results with densitometry. The losses of FFM assessed by skinfold thicknesses, BMI and impedance equations were almost similar, but significantly larger than the reduction in FFM measured by densitometry. These deviations were mainly the result of significantly larger differences from densitometry before compared to after weight loss. No correlation was found between change in FFM by densitometry and change in resistance measured by the bioelectrical impedance method in both sexes. It is concluded that application of published prediction formulae in weight loss studies are less appropriate and will lead to changes in FFM that are significantly different from the changes estimated by densitometry or deuterium oxide dilution.

Adult↗

PubMed1982

Prolactin responses, menstrual cycles, and body composition of women runners.

Fourteen young women with normal menses participated in an endurance running program to investigate the effects of physical training on menstrual function, plasma PRL, and body composition. Body composition, measured by hydrostatic weighing, and PRL (basal and TRH-stimulated ) were determined initially and after each subject had increased her weekly mileage by 30 miles (delta 30) and 50 miles (delta 50). Mean (+/- SEM) total body weight did not change, but the subjects became significantly leaner (relative fat, 25.5 +/- 1.3% at baseline vs. 22.4 +/- 0.9% at delta 50; P less than 0.02). Thirteen women developed menstrual changes (mainly oligomenorrhea), but not amenorrhea. Mean (+/- SEM) unstimulated PRL levels were 16.8 +/- 3.1%, 16.9 +/- 2.4, and 11.5 +/- 2.1 ng/ml at baseline, delta 30, and delta 50, respectively (P less than 0.03 at delta 50 compared to baseline and delta 30). Mean ( +/- SEM) integrated TRH-stimulated PRL responses increased from 5002 +/- 462 ng/ml.min at baseline to 5748 +/- 609 mg/ml.min at delta 30 and 6535 +/- 552 ng/ml.min at delta 50, and were significantly different from one another (F = 4.01; P less than 0.04). Endurance training, without total body weight loss or extreme leanness, results in frequent menstrual dysfunction. Other authors have shown that young female athletes have an increased PRL response to acute exercise compared to nonathletes. One mechanism responsible for menstrual dysfunction in endurance-trained women may be frequent and exaggerated PRL responses to exercise and other stimuli.

Adult↗

PubMedDate not supplied

[Assessment of body composition in groups of subjects with different body size. Comparison of skinfold thickness and impedance methods].

The aim of our study was to compare plicometry and bioelectrical impedance analysis as methods for body composition assessment (fat mass-FM%, fat-free mass-FFM) and to extrapolate population-specific equations in order to predict the plicometrically-derived FM and FFM on the basis of body resistance. A cross-sectional study was carried out at the Diabetes Out-Patient Clinic, Department of Internal Medicine, University of Palermo, Italy. We examined 102 subjects (45 men, 57 women, age range 30-45 years) divided into three groups: Group N (36 normal weight subjects, body mass index-BMI = weight/height2 = 24.5 +/- 0.8), Group O (35 obese subjects, BMI = 35.1 +/- 0.4), and Group GO (morbid obese subjects, BMI = 49.2 +/- 1.2) as well as a control group of 30 subjects (12 men, 18 women, age range 30-45 years, BMI = 20.9-63.1). We measured the following parameters: bioelectrical impedance analysis (body resistance: R), plicometry (triceps, biceps, subscapular, and suprailiac skinfolds), height (Ht), weight (W). The two methods were comparable in Groups N and O. In Group GO, however, especially in men and for FM%, measurements were significantly different. Plicometrically-determined FM% and FFM-Kg were significantly correlated to R.W/Ht2 (r = 0.821, p < 0.0001) and to Ht2/R (r = 0.867, p < 0.0001) respectively. The following prediction formulas for plicometric FM and FFM from body resistance and anthropometric variables were obtained: 1) FM% = 22.3 (R.W/Ht2)-2.2, and 2) FFM-Kg = 1.1 (Ht2/R)-3.1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed2005

The effects of 10 weeks of reforestation work on body composition.

OBJECTIVE: To document changes in body composition and body mass in male and female tree planters. METHODS: Height, mass, skin-fold thickness, and limb girths were measured in 17 male and 5 female tree planters before and after 10 weeks of work. RESULTS: Significant decreases were found in body mass (80.6 +/- 10.7 kg vs 76.8 +/- 8.5 kg) and body fat (13.3% +/- 5.5% vs. 10.4% +/- 5.0%) in the men (P < .05). No changes in skin-fold-corrected limb girths were found in the men or women. Initial body mass was significantly (P < .05) correlated with mass loss in men (r2 = .46) and women (r2 = .67). Estimated daily energy consumption was 20680.1 +/- 2204.5 kJ for men and 14516.6 +/- 2077.3 kJ for women, and estimated daily fat consumption was 194.2 +/- 30.1 g for men and 132.3 +/- 35.6 g for women. CONCLUSIONS: Ten weeks of tree planting leads to significant decreases in body mass and body fat in men while maintaining skin-fold-corrected limb girths.

Adipose Tissue↗

PubMed1986

The effects of varying energy and nitrogen intake on nitrogen balance, body composition, and metabolic rate.

Body protein content (as measured by N balance) is normally regulated at a constant level, but is influenced by the level of both energy and N intake. Energy and N act synergistically on N balance. Not all forms of energy are equally effective in maintaining zero N balance; approximately 500 kcal of carbohydrate are required daily by the brain, and this minimum amount of dietary carbohydrate cannot be replaced by fat without loss of body N. Acute illness is accompanied by a catabolic state and an increase in the minimum N intake required for zero N balance. Nutritional depletion induces a metabolic state similar to that typical of growing organisms, in that N can be retained at zero energy balance. BMR includes essential thermogenesis and facultative thermogenesis. In addition, food has a specific dynamic action; it increases metabolic rate. Nutrient-induced increases in metabolic rate are exaggerated in acutely ill patients, such that large amounts of IV glucose may constitute a metabolic stress when given to patients. Equivalent N sparing can be obtained when as much as half of the glucose calories are replaced by fat calories. N balance is an incomplete index of nutritional status, and important information may be gained from measurements of body composition of acutely ill patients; in particular, the degree of expansion of ECW may predict outcome.

Acute Disease↗

PubMedDate not supplied

Hierarchical differences in body composition of professional Sumo wrestlers.

The body composition of 36 professional Sumo wrestlers and 39 collegiate male students were assessed densitometrically. The means of body weight, BMI and %fat for Sumo wrestlers were 117.1 kg, 36.5 and 26.2%, extraordinarily large compared with untrained men (p < 0.001). Results of the analysis of variance of divisions of Sumo wrestlers revealed significant differences in body weight, fat-free mass, fat mass, BMI, fat-free mass index (FFM/height2) and fat mass index (FM/height2). For the visual expression of the hierarchical differences of body composition, fat mass index and fat-free mass index of the wrestlers in various leagues were plotted on a body composition chart. Wrestlers in the Sekitori division had significantly larger fat-free mass index scores in comparison with wrestlers from the lower divisions who share a common area of the chart. The cut-off point of fat-free mass index which divided Sekitori wrestlers from other wrestlers is approximately 30 and this value may be one of the anthropometrical indications of whether or not a Sumo wrestler is destined to be successful.

Adipose Tissue↗

PubMed2002

Effects of high-calorie supplements on body composition and muscular strength following resistance training.

BACKGROUND: Seventy-three healthy, male subjects randomly divided into 3 groups participated in a study to determine the effects of 2 high-calorie nutritional supplements on body composition, body segment circumferences, and muscular strength following a resistance-training (RT) program. METHODS: In addition to their normal diets group 1 (CHO/PRO; n=26) consumed a 8.4 Mj x day(-1) (2010 kcal) high calorie, high protein supplement containing 356 g carbohydrate and 106 g protein. Group 2 (CHO; n=25) consumed a carbohydrate supplement that was isocaloric with CHO/PRO. Group 3 (CTRL; n=22) received no supplement and served as a control. All subjects were placed on a 4-day x week(-1) RT program for 8 weeks. RESULTS: Dietary analysis revealed no significant differences in total energy consumption or nutrients at any time in the non-supplemented diets of the 3 groups. Significant (p= or <0.05) increases in body mass (BM) and fat-free mass (FFM) were observed in CHO/PRO and CHO compared to CTRL. Mean (+/- SD) increases in BM were 3.1+/-3.1 kg and 3.1+/-2.2 kg, respectively. Fat-free mass significantly (p= or <0.05) increased 2.9+/-3.4 kg in CHO/PRO and 3.4+/-2.5 kg in CHO. Muscular strength, as measured by a one-repetition maximum in the bench press, leg press, and lat-pull down increased significantly (p= or <0.05) in all groups. No significant differences in strength measures were observed among groups following training. CONCLUSIONS: Results indicate that high-calorie supplements are effective in increasing BM and FFM when combined with RT. However, once individual protein requirements are met, energy content of the diet has the largest effect on body composition.

Adolescent↗

PubMed2006

Measuring body composition.

Several aspects of body composition, in particular the amount and distribution of body fat and the amount and composition of lean mass, are now understood to be important health outcomes in infants and children. Their measurement is increasingly considered in clinical practice; however, paediatricians are often unsure as to which techniques are appropriate and suitable for application in specific contexts. This article summarises the pros and cons of measurement technologies currently available for paediatric application. Simple techniques are adequate for many purposes, and simple regional data may often be of greater value than "whole body" values obtained by more sophisticated approaches.

Absorptiometry, Photon↗

PubMed1990

Some aspects of body composition in cancer.

Changes in body composition, in cancer as in benign disease, simple starvation or overfeeding, show the integrated effect of a period of metabolic imbalance. Therefore, accurate measurements of body composition can help to elucidate the mechanisms that bring about the imbalance. Techniques of measurement that depend for their accuracy on the constancy of some property of the entire fat-free tissues are unlikely to give accurate results in obese or wasted patients. It is more informative, and more accurate, to measure fat, water, protein and mineral separately, and at present this is best done by dilution of labelled water and multi-element in vivo neutron activation analysis. Changes should be determined by sequential measurement wherever possible; otherwise results must be compared with 'normal' values found by measuring healthy subjects, correcting if necessary for differences in age and stature between patients and healthy subjects.

Body Composition↗