Genotype by environment interactions using fast-growing, lean or fat broiler chickens, originating from The Netherlands and Israel, raised at normal or low temperature

Male and female broiler chicks from five different broiler crosses (WI = Israeli chicks selected for body weight; LF and HF = Israeli chicks selected for low and high abdominal fat, respectively; FC = Dutch chicks selected for feed conversion; and WN = Dutch chicks selected for body weight) were raised under normal and subnormal temperatures. Weight gain, protein and fat content in the carcass, and feed and protein efficiency were determined at 4 and 6 wk of age, and at equal body weight. In addition to an overall effect of genotype, contrasts between Dutch (WN and FC) and Israeli (WI and LF) chicks and between chicks selected for body weight (WN and WI) or leanness (LF and FC) were examined. Temperature, genetic background, sex, and age affected all traits examined. Significant interactions were observed for weight gain, protein deposition, and feed and protein efficiency but were less evident for fat deposition. At low temperature, the broilers derived from Dutch strains had higher weight gain and protein deposition than those derived from Israeli strains; at the normal temperature the Israeli chicks performed better. The relations between body composition, weight gain, and efficiency are discussed to explain the interactions found.

Effect of chronic insulin administration on food intake and body weight in rats

Insulin was chronically administered to rats to determine its effect on the daily changes in food intake and body weight. Animals received regular insulin via 14-day osmotic minipumps in doses of 0.0, 0.5, 1.0, 3.0, and 5.0 IU/day treated either with (+GLU) or without glutamic acid (-GLU). Previous studies have shown that glutamic acid prevents insulin aggregation in the minipumps to provide a more stable flow rate. Food intake and body weights were measured each day of treatment. Chronic insulin treatment was ineffective in promoting changes in animals receiving any dose of insulin except the highest dose. Animals receiving 5.0 IU/day insulin + GLU experienced a transient hyperphagia and weight gain followed by a suppression in food intake and body weight by Day 4 of treatment. Effects were attenuated in animals receiving insulin -GLU. Plasma insulin concentrations on Day 14 were similar for all doses, suggesting a compensation took place either in insulin degradation or endogenous insulin production. Results indicate that glutamic acid treatment enhances the effects of chronic insulin administration via osmotic minipumps.

Diet and body composition. Effect of very low calorie diets and exercise

Obesity is the presence of excess body fat and is associated with a variety of medical conditions which increase morbidity and mortality. Millions of individuals participate in weight-reduction programmes which include reduced calorie diets and may also include exercise. Very low calorie diets (VLCD) of 400 to 800 kcal/day appear attractive as they generally show an increase in weight loss from 0.2 to 0.5 kg/week found with the traditional diet to 1.5 to 2.0 kg/week. Early use of very low calorie diets with poor quality protein and loose medical supervision resulted in about 60 deaths, many of which were attributed to loss of lean body mass and in particular, cardiac muscle atrophy. Although current very low calorie diets are presumed safe, concern regarding preservation of lean body mass (LBM) remains. Investigators have used exercise to slow the depletion of lean body mass during very low calorie diets; however, the results are not conclusive. A host of different methodologies and questionable documentation and design of exercise protocols precludes a definitive statement for the benefits of exercise during very low calorie diets for the purpose of LBM retention.

Body composition and exercise performance in patients with chronic obstructive pulmonary disease

To investigate whether a compromised nutritional state may limit exercise performance in patients with chronic obstructive pulmonary disease we studied 54 such patients (FEV1 less than 50% and arterial oxygen tension (PaO2) greater than 7.3 kPa) whose clinical condition was stable and who were admitted to a pulmonary rehabilitation centre. Fat free mass was assessed anthropometrically (from skinfold measurements at four sites) and by bioelectrical impedance; creatinine height index and arm muscle circumference were also assessed. The mean (SD) distance walked in 12 minutes was 845 (178) m. No association was established between the distance walked and spirometric measures. A good correlation was found between the distance walked and fat free mass in the whole group (r = 0.73 for impedance measurements and 0.65 for skinfold thickness) and in a subgroup of 23 lean patients (body weight less than 90% of ideal weight; r = 0.66 for impedance measurements and 0.46 for skinfold thickness). Body weight correlated with the distance walked only in the whole group (r = 0.61). On stepwise regression analysis fat free mass measured by bioelectrical impedance, maximal inspiratory mouth pressure, and PaO2 accounted for 60% of the variation in the distance walked in 12 minutes. We conclude that fat free mass, independently of airflow obstruction, is an important determinant of exercise performance in patients with severe chronic obstructive pulmonary disease.

Insulin-like growth factor-I as a reflection of body composition, nutrition, and puberty in sixth and seventh grade girls

Large variations in nutritional intake have profound effects on the GH-insulin-like growth factor-I (IGF-I) axis in children and adults, but the effect of normal variations in nutrition on IGF-I concentrations is largely unstudied, particularly during puberty. We measured serum IGF-I concentrations in 325 sixth and seventh grade girls (12.4 +/- 0.7 yr) at the beginning of a multisite school-based health curriculum. The mean serum IGF-I level among the 243 girls with complete data was 573 +/- 244 micrograms/L. Pubertal stage was significantly associated with IGF-I (P less than 0.0001, by analysis of variance). Mean concentrations rose from 427 +/- 198 micrograms/L among those at the earliest pubertal stages to 639 +/- 219 micrograms/L among the mature girls. After adjusting for the association with the stage of pubertal development, serum IGF-I was not significantly associated with measures of body composition (body mass index, triceps skin fold thickness, waist/hip ratio, height, and weight). Additionally, IGF-I concentrations were not associated with nutritional intake (total calories, total protein, total fat, and total carbohydrate) or such measures of nutrition as serum iron, hemoglobin, red cell mean corpuscular volume, white cell count, and cholesterol. IGF-I concentrations, however, were significantly correlated with transferrin concentrations, another possible index of nutritional status (r = 0.29; P less than 0.0001). IGF-I is not a clinically useful index of nutritional status among normal pubertal girls.

Influences of chemical sympathectomy and simulated weightlessness on male and female rats

Maximum oxygen consumption (VO2max) has been shown to be reduced after periods of simulated weightlessness. To assess the role of the sympathetic nervous system in these reductions, Sprague-Dawley rats were either chemically sympathectomized (SYMX) or injected with saline (SHAM) and assigned to head-down suspension (HDS), horizontal restraint with the hindlimbs weight bearing (HWB), or cage-control (CC) conditions. VO2max, run time (RT), and mechanical efficiency (ME) were measured before suspension and on days 7 and 14. Male and female SHAM HDS groups exhibited reduced measures of VO2max (12-13%) after 7 and 14 days, and this decrease was attenuated in the SYMX and HWB rats. HDS resulted in a significant reduction in RT (9-15%) in both the male and female rats, and ME was significantly reduced after HDS in male and female SYMX and male SHAM rats (23-33%) but not in the female SHAM rats. Lesser reductions in ME were observed in the HWB rats. HDS and HWB were associated with lower body, fat-free, and fat masses, which were similar in male and female rats as well as for the SHAM and SYMX conditions. In a related HDS experiment with normal rats, plasma norepinephrine and epinephrine were increased by 53 and 42% after 7 days, but only epinephrine returned to baseline after 14 days. It was concluded that chemical sympathectomy and/or a weight-bearing stimulus will attenuate the loss in VO2max associated with simulated weightlessness in rats despite similar changes in body mass and composition. The mechanism(s) remains unclear at this time.

Basal metabolic rate, body composition and whole-body protein turnover in Indian men with differing nutritional status

1. Three groups of adult men were studied in Bangalore, India: two groups were controls who had been receiving an adequate diet. Of these, one group, designated 'normal weight controls', had a mean body mass index of 22; the other group, 'underweight controls', had a mean body mass index of 16.7. The third group consisted of poor labourers, whose daily food intake had been less than 10 MJ and whose mean body mass index was 16.6. Previous studies had shown that such men had a lower basal metabolic rate than well-nourished Indian control subjects. 2. The object of the present study was to find out whether a reduced rate of protein turnover, measured after a single dose of [15N]glycine, contributed to a lower basal metabolic rate. It was found, however, that after adjusting for body weight and fat-free mass by analysis of co-variance there was no significant difference in basal metabolic rate between the three groups. Adjusted rates of protein synthesis were higher in the underweight controls and the undernourished labourers than in the normal weight controls, but not significantly so. 3. Estimates based on creatinine excretion showed that within the fat-free mass the underweight groups had a higher proportion of non-muscle to muscle mass. This may explain the somewhat higher rates of protein turnover in these groups. 4. Nitrogen flux (Q) was determined from 15N abundance in two end products, urea (QU) and ammonia (QA). In the underweight and undernourished groups the ratio QU/QA was increased compared with the normal weight group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometric and biochemical assessment of the nutritional state in depression: evidence for lower visceral protein plasma levels in depression

Severe depression is characterized by anorexia and weight loss, symptoms that could endanger the patient's nutritional state. In order to investigate the nutritional state of depressed patients we determined the following in 113 healthy controls and depressed inpatients: (1) anthropometric variables such as body weight, ideal body weight (IBW), percentage of IBW, mean arm circumference, triceps skinfold thickness and arm muscle circumference, and (2) biochemical parameters such as albumin (Alb), prealbumin (Prealb), and transferrin (Tf). We were unable to detect any differences in the anthropometric parameters between healthy controls, minor and major depressed patients. Depressed patients exhibited significantly lower Alb and Tf levels than healthy controls. The drop in both plasma proteins was highly sensitive (72%) and specific (92%) for melancholia. These results may point towards the existence of a disorder in protein homeostasis or protein malnutrition without a marasmic component.

Body composition and longevity: is there a longevous morphotype?

Life expectancies are increasing in populations throughout the world. As infectious diseases decline as causes of mortality, certain degenerative diseases including cardiovascular disease and cancer account for an increasing percentage of deaths. As more people survive into old age, the intrinsic limits on the human life span will be reached. It is clear that genetic factors have a strong influence on the life span. It is not clear, however, that there are identifiable longevous body types (morphotypes). For the first time in human history, large numbers of people 80 years old and older are available for study. If there is an association between body form and composition and superior longevity, it should be possible to identify its major aspects. Monitoring changes in body composition throughout the life cycle and the retention of reserves to be drawn upon when disease or trauma threaten life may provide the basis for prediction of the course of life threatening diseases. The unusually high survival of morphotypes classifiable as "moderately obese" casts doubt on standards recommending "ideal weights for height" if the criterion in question is survival.

Aspects of neuroregulation of body composition and insulin secretion

Perturbances in the autonomic nervous control of different target tissues (e.g. endocrine pancreas, brown adipose tissue) are present in the genetically obese (fa/fa) rat. These disorders are probably secondary to central dysregulation(s). In view of the reported effects of CRF in stimulating sympathetic nerve-mediated mechanisms while inhibiting vagus nerve-mediated ones, ovine CRF (oCRF) was administered for 7 days into the cerebral ventricles of fa/fa rats. oCRF treatment stopped the excessive weight gain of the obese animals. The oCRF effect was unrelated to changes in food intake, as the two groups were pair-fed. oCRF-treated obese rats were characterized by a decrease in basal hyperinsulinemia, increases in brown adipose tissue weight and activity, and decreases in hepatic glycogen content and epididymal fat pad weight. It is suggested that intracerebroventricular oCRF administration to obese fa/fa rats prevents the increase in body weight observed in vehicle-infused obese rats by modulating the impaired autonomic nervous control of different target tissues. This does not occur in lean rats.

Effect of dietary restriction and/or exercise on 23-h metabolic rate and body composition in female rats

This study examined the effects of three levels of dietary intake [ad libitum fed (AL), moderately severe (MSR), and severe restriction (SR)] and two levels of exercise [cage confinement (CC) and exercise training (E)] on 23-h resting metabolic rate (RMR) and body composition in 47 female Sprague-Dawley rats. At the end of the 9-wk study, the MSR and SR groups weighed approximately 81 and 61%, respectively, of the AL-CC group. RMR was depressed for the MSR and SR groups compared with the AL-CC group. This was true whether expressed on an absolute (ml/min) or relative (ml.min-1.kg-0.75) basis. On a relative basis, which accounts for changes caused by weight loss alone, the RMR decreased by approximately 12 and 19%, respectively, for the MSR and SR groups compared with the AL-CC group. Although E resulted in significant differences in fat mass, percent fat, percent water, and heart mass between the AL groups, there were no significant differences between E and CC groups at either the MSR or SR level of dietary intake for any of the variables measured (i.e., body composition, muscle mass, RMR). Thus E does not appear to affect the composition of lost weight or RMR during diet-induced weight loss for female rats of normal weight.

Effects of acute and long-term exercise on self-efficacy responses in sedentary, middle-aged males and females

We examined the effects of acute and long-term exercise on perceptions of personal efficacy in sedentary, middle-aged males and females. Both males and females demonstrated significant increases in efficacy following acute exercise. Females, who had demonstrated initially lower self-perceptions than males, made dramatic increases in efficacy during the exercise program, equaling or surpassing those of males. Exploratory analyses revealed significant relationships between self-efficacy and subsequent physiological responses to exercise.

Physiological responses to prolonged treadmill walking with external loads

Limited information is available regarding the physiological responses to prolonged load carriage. This study determined the energy cost of prolonged treadmill walking (fixed distance of 12 km) at speeds of 1.10 m.s-1, 1.35 m.s-1, and 1.60 m.s-1, unloaded (clothing mass 5.2 kg) and with external loads of 31.5 and 49.4 kg. Fifteen male subjects performed nine trials in random order over a 6-week period. Oxygen uptake (VO2) was determined at the end of the first 10 min and every 20 min thereafter. A 10-min rest period was allowed following each 50 min of walking. No changes occurred in VO2 over time in the unloaded condition at any speed. The 31.5 and 49.4 kg loads, however, produced significant increases (ranging from 10 to 18%) at the two fastest and at all three speeds, respectively, even at initial exercise intensities less than 30% VO2max. In addition, the 49.4 kg load elicited a significantly higher (P less than 0.05) VO2 than did the 31.5 kg load at all speeds. The measured values of metabolic cost were also compared to those predicted using the formula of Pandolf et al. In trials where VO2 increased significantly over time, predicted values underestimated the actual metabolic cost during the final minute by 10-16%. It is concluded that energy cost during prolonged load carriage is not constant but increases significantly over time even at low relative exercise intensities. It is further concluded that applying the prediction model which estimates energy expenditure from short-term load carriage efforts to prolonged load carriage can result in significant underestimations of the actual energy cost.

Body fat in the adult Danish population aged 35-65 years: an epidemiological study

The purpose of the study was: (1) to estimate body fat and body fat distribution in the general population of Danes aged 35-65 years and thus provide tables of normal values for adult Danes in these age groups; and (2) to assess the effects of age and gender on relations between measures of obesity and of fat distribution. Hitherto, the only available results from the Danish population have been on BMI. Of the 3608 invited subjects 2987 (83 per cent) attended the examination. Body fat and fat distribution were estimated from measurements of electrical impedance and from circumference measurements. The study showed large differences in body fat and fat distribution between men and women. There was a difference in total body fat of 4.5 and 6.9 kg in men and women respectively between the groups aged 35 and 65 years. Fat percentage increased 36 per cent in women and 30 per cent in men between the groups aged 35 and 65 years. There was a difference in waist/hip ratio (WH ratio) between men and women at all age groups. Of the women 46 per cent had WH ratios above 0.8 and 14 per cent of the men had WH ratios above 1.0, suggesting that cut-off points for WH ratio as an indicator of cardiovascular risk are population specific. This may be caused by a different distribution of other cardiovascular risk factors in the Danish population than in other populations. Men had larger WH ratios per body fat mass with age, whereas in women there was no effect of age on this relation. Furthermore the WH ratio increments in this population took place before the age of 55 years in men, but after 55 years in women. The results may contribute to explain gender differences in morbidity and mortality with increasing age.

Evaluation of growth and changes in body composition following neonatal diagnosis of cystic fibrosis

Early deficits in nutritional status that might require specific treatment and early response to nutritional therapy were studied longitudinally in 25 infants with cystic fibrosis (CF) diagnosed by neonatal screening, using anthropometric and research body composition methodology, and evaluation of pancreatic function. At the time of confirmed diagnosis (mean 5.4 weeks), body mass, length, total body fat (TBF), and total body potassium (TBK) were all significantly reduced. Following diagnosis and commencement of therapy there was a normalization of weight, length, and TBK by 6-12 months of age, indicating catch-up growth. But in some individuals the response was incomplete, and as a group, mean total body fat remained significantly lower than normal at 1 year of age. Seven of 25 (28%) were pancreatic sufficient at diagnosis, and all but one had evidence of declining pancreatic function requiring the institution of pancreatic enzyme therapy during the next 1-9 months. The median age of commencement of enzyme therapy was 10 weeks (range 5 weeks to 11 months). These longitudinal assessments emphasize the dynamic changes occurring in absorptive function, body composition, and nutritional status following neonatal diagnosis of cystic fibrosis and may reflect previously described abnormalities of energy metabolism in this age group. Abnormal body composition is evident in most CF infants following diagnosis by neonatal screening but pancreatic damage may still be evolving. We suggest that early active nutritional therapy and surveillance for changes in pancreatic function are warranted in CF infants diagnosed by neonatal screening.

Validation of body composition by dual energy X-ray absorptiometry (DEXA)

The present study validates the use of dual energy X-ray absorptiometry (DEXA) for measurement of body composition. The precision error was expressed as the SD (CV%) for fat mass, FAT%, lean tissue mass, and total body bone mineral: 1.1 kg (6.4%), 1.6% (5.7%), 1.4 kg (3.1%), and 0.03 kg (1.2%), respectively. The accuracy study in vitro used (1) mixtures of water and alcohol, (2) mixtures of ox muscle and lard, and (3) dried bones. In the clinically relevant range of values there were only small influences on DEXA measurements of variations in amount and composition of the soft tissue equivalents. The accuracy study in vivo compared the components of body composition measured recently by DEXA and earlier by dual photon absorptiometry, counting of naturally occurring total body 40K, and body density by underwater weighing in 25 healthy adult subjects. We found agreement between fat percentage (and lean body mass) by DEXA and the three established measurements modalities; mean differences were (-5.3 to -0.4%) and (-0.7 to 2.5 kg) for fat percentage and lean body mass, respectively. We conclude that DEXA provides a new method of measuring body composition with precision and accuracy errors, which are compatible with the application of DEXA in group research studies and probably also in clinical measurements of the single subject.

Effect of increased training volume on blood lipids and lipoproteins in male collegiate swimmers

This study was conducted to assess whether a previously described dose-response relationship between the amount of exercise and the magnitude of change in blood lipid and lipoprotein levels is observed with large volumes of exercise in young, healthy individuals. Blood lipid and lipoprotein levels were monitored during a 25-wk season of training and competition in experienced male collegiate swimmers, who were divided into two groups matched for swimming skill. After an initial 4-wk conditioning period for both groups, one group (N = 11) underwent a 6-wk period during which their training volume was increased from 22,000 m.wk-1 to 44,000 m.wk-1. The other group (N = 13) maintained their swimming distance at 22,000 m.wk-1 during this period. During the remaining 15 wk of the season, both groups swam approximately 22,000 m.wk-1. Swimmers' body weights did not change over the season, but body fat decreased significantly (P less than 0.01). No changes in HDL cholesterol were observed during the season in either the increased training or the regular training groups. Total and LDL cholesterol levels were lower at 20 wk than at the start of the study, but final levels did not differ from initial levels. Thus, the volume of swimming exercise may not be related to the degree of change in blood lipid and lipoprotein levels in healthy subjects with high activity levels.

Effects of ovariectomy on thermogenesis in brown adipose tissue and liver in Syrian hamsters

Weight gain in ovariectomized Syrian hamsters occurs without increased food intake, which suggests that metabolic efficiency may be enhanced through a reduction in energy expenditure. We examined the effect of ovariectomy on metabolic activity in brown adipose tissue and liver. Four groups of hamsters (n = 13, each) were killed 0, 2, 4, or 16 weeks following ovariectomy. Ovariectomized hamsters rapidly gained weight without overeating. Body weights stabilized after 8 weeks and remained 12-17% above sham-operated control weights for the duration of the experiment. Weight gain in the hamsters ovariectomized for 16 weeks was characterized by significant increases in retroperitoneal white adipose tissue weight and carcass lipid content. Similar trends were seen in 2-week and 4-week ovariectomized animals. There were no differences in interscapular brown adipose tissue weight, protein content, DNA content, or norepinephrine (NE) content among sham-operated and 2-, 4-, or 16-week ovariectomized hamsters, indicating that ovariectomy had no effect on brown adipose tissue growth. Similarly, there was no difference in either sympathetic nervous system activity (estimated by the rate of NE turnover) or mitochondrial GDP binding among the four groups of hamsters. In contrast, hepatic cytochrome P-450 activity was significantly reduced 2, 4, and 16 weeks after ovariectomy. These results suggest that reduced thermogenic activity in liver, but not in brown adipose tissue, could contribute to the weight gain in Syrian hamsters after ovariectomy.

[Metric index in the evaluation of body composition in 7-8-year-old children]

The classification of the body constitution of then 7-8 years old school children in Moscow and Berlin (416 persons) was carried out using the metric index. The metric index, based on the data of the body length, transversal and sagittal diameters of the chests and the age sex of children, clearly indicated the common tendency in the distribution of body constitution types in connection with the lepto- and picnomorphy. Correlation of the body constitution with the physical development was also found, its coefficients are 0.624--for girls and 0.500--for boys.

Anthropometric, body composition and performance variables of young elite female basketball players

The purpose of the study was to determine the physique and body composition of young female basketball players and to examine these variables in relation to their playing position. Eighteen members of the under seventeen England Basketball squad were measured on twenty different anthropometric sites from which somatotype and body composition were calculated. Four performance measures, vertical jump, anaerobic power, right and left grip strength and laterality were also measured. The variables of the basketball players grouped according to playing position were then compared statistically using ANOVA. Centres had the largest measures of physique and body composition followed by the forwards and then the guards. These differences were significant, particularly between the centres and the guards. The centres were much taller, had longer limb lengths, hip widths and were more muscular.

Physical activity, body composition, and blood pressure: a multimethod approach

The purpose of the current investigation was to evaluate, using multiple measures of physical activity, the relationships among physical activity, body composition, resting heart rate, and blood pressure in an adult population. Subjects were 221 male (135 normal weight, 86 overweight) and 221 female (156 normal weight, 65 overweight) subjects participating in a longitudinal study of cardiovascular risk factors in families. All subjects were administered three physical activity questionnaires. Principal components analyses were conducted to reduce measures into empirically derived subscales; this analysis revealed five stable factors in men and four in women. Results indicated that aerobic/leisure time significantly correlated to body composition and resting heart rate in both men and women. Additionally, aerobic/leisure time activity was related to blood pressure in women, and moderate activity was related positively to blood pressure in men. No other form of activity (e.g., light activity, anaerobic activity) was related to either adiposity or blood pressure. The implications of these results are discussed, and future research directions are highlighted.

Brown (BAT) and white (WAT) adipose tissue in high-fat junk food (HFJF) and chow-fed rats with dorsomedial hypothalamic lesions (DMNL rats)

Male weanling rats received dorsomedial hypothalamic nucleus lesions (DMNL) or sham operations and were fed for 173 postoperative days a high-fat diet and given a 32% sucrose solution as drinking fluid. This was supplemented with chocolate chip cookies, potato chips and marshmallows. Other DMNL and sham-operated controls were fed lab chow instead of the above high-fat junk food diet (HFJF) and given tap water instead of 32% sucrose solution. All animals were killed on postoperative day 174. Caloric intake per 100 g body weight was similar in all groups; however, the HFJF fed control and DMNL rats had significantly elevated carcass fat. Since HFJF-DMNL rats were not nearly as obese as the HFJF control animals, it appears that the DMNL offered some protection against the HFJF-diet-produced obesity. When their smaller body size is considered. DMN lesions had no effect on brown adipose tissue (BAT) mass in chow-fed or HFJF fed rats, whereas BAT size was significantly enlarged in HFJF-fed control animals. This suggests but does not prove that HFJF-fed controls, but not DMNL rats, may be using dietary-induced thermogenesis (DIT) to attenuate their obesity. We hypothesize that the HFJF-fed DMNL may not be enhancing DIT as reflected in normal BAT size, because they had not attained a degree of fatness to activate this system, or the DMN lesions impaired its activation. Both HFJF-fed groups showed reduced linear growth compared to their counterparts. The reason for stunting is uncertain, but may be related to their low plasma insulin concentrations.

A comparison of measurements of lean body mass derived by bioelectrical impedance, skinfold thickness and total body potassium. A study in obese and non-obese normal subjects

The measurement of body composition is an important part of metabolic and epidemiological research, but most currently available methods are complex and expensive. We have, therefore, compared measurements of fat mass (FM) and lean body mass (LBM), obtained using a commercially available bioelectrical impedance monitor (The Holtain Body Composition Monitor) (IMP), and by measuring skinfold thickness (SFT), with values obtained by measuring total body potassium (TBK). Twenty subjects, 10 with a body mass index (BMI) less than 30 (kg m-2), (non-obese) and 10 with BMI greater than or equal to 30 (obese) took part in the study. There was a strongly significant linear relationship between LBM calculated from TBK and that calculated from impedance (IMP), in both non-obese and obese groups analysed separately (non-obese: r = 0.92; p less than 0.001 and obese: r = 0.92; p less than 0.001) and together (all: r = 0.89; p less than 0.001). LBM calculated from TBK was strongly linearly correlated with values derived from SFT for non-obese (r = 0.91; p less than 0.001) but not for obese subjects. Mean values of LBM of non-obese subjects derived by each method were not significantly different (TBK: 51.3 +/- 10.40 kg; IMP: 53.18 +/- 10.37 kg; SFT: 48.87 +/- 9.48 kg), but significant differences existed when the subjects were obese (TBK: 51.86 +/- 9.65 kg; IMP: 58.69 +/- 8.55 kg; SFT: 67.61 +/- 8.14 kg; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in body composition and energy expenditure after six weeks' growth hormone treatment

Changes in body composition and energy expenditure were assessed in 15 children after six weeks of human growth hormone (hGH) treatment. Body composition measurements were made by stable isotope labelled water (H2(18)O) dilution, bioelectrical impedance, and skinfold thickness techniques. Energy expenditure was assessed both by indirect ventilated hood calorimetry (resting energy expenditure) and the stable isotope doubly labelled water (2H2(18)O) technique (free living daily total energy expenditure). Mean increases in weight of 0.96 kg and fat free mass of 1.37 kg and a mean decrease in fat mass of 0.41 kg were observed. Significant increases both in resting energy expenditure and free living daily energy expenditure were detected. Absolute changes in fat mass and resting energy expenditure were correlated. The data suggest (i) that the increase in the fat free mass is the most significant early clinical measure of hGH response and (ii) that hGH increases the metabolic activity of the fat free mass. Monitoring such changes may be predictive of the efficacy of hGH in promoting growth.

Effect of cholecystokinin immunization, enhanced food intake and growth of swine on lean yield and carcass composition

It was previously reported that cholecystokinin (CCK) immunization of swine increased food intake 8.2% and rate of growth 10.6%. This report compares carcass yields of lean, fat and bone tissues of CCK-immunized vs. human serum globulin (hSG) control animals. The experiment involved 24 castrated pigs, age 75 d, weight 25.6 kg, randomly assigned to the CCK-immunized or hSG control groups (2 pigs/pen, 6 pens/group). Food was offered for ad libitum access. Carcasses of CCK-immunized animals (vs. hSG controls) were 8.7% heavier (P less than 0.01) and 2.4% longer (P less than 0.01). Carcass yield and composition were analyzed by dissection to lean, fat and bone fractions and by proximate analysis of the resultant lean fraction. Carcasses from the CCK-immunized animals had 2.7 kg more lean (P = 0.09) and 1.8 kg more fat (P = 0.04). Proximate analysis indicated there were no significant differences in composition of the lean fraction. The 7.2% heavier lean fractions of the CCK-immunized animals contained 9.2% more protein (P = 0.09) and 5.1% more fat (P = 0.05). Lean:fat and protein:fat ratios were not significantly altered.

Effects of diabetes and insulin on photoperiodic responses in Siberian hamsters

Short day pineal melatonin secretion patterns cause gonadal regression in Siberian hamsters, an effect due to alterations in gonadotropin secretion that ultimately affects the gonads. An analogous endocrine response sequence may underlie short day (melatonin)-induced decrease in body weight (fat) in this species. A potential mediating hormone for this effect of melatonin may be insulin. The purpose of the present experiments was to determine whether alterations in insulin status might affect the photoperiodic control of body weight (fat) and reproductive condition. Insulin was controlled by inducing experimental diabetes mellitus via injections of streptozotocin across several days, followed by treatment with one of two doses of long-lasting insulin. Both insulin doses normalized urinary glucose, but not body weight in long days. Seven weeks of short day exposure caused gonadal regression in all groups regardless of insulin status. The magnitude of the short day-induced decrease in body weight and carcass lipid was directly related to long day baseline body weights; however, the body weight nadir reached was similar among the groups. A 'regulation' of seasonally appropriate body weight (fat) is implied by these findings.

Body mass index as a measure of body fatness: age- and sex-specific prediction formulas

In 1229 subjects, 521 males and 708 females, with a wide range in body mass index (BMI; 13.9-40.9 kg/m2), and an age range of 7-83 years, body composition was determined by densitometry and anthropometry. The relationship between densitometrically-determined body fat percentage (BF%) and BMI, taking age and sex (males = 1, females = 0) into account, was analysed. For children aged 15 years and younger, the relationship differed from that in adults, due to the height-related increase in BMI in children. In children the BF% could be predicted by the formula BF% = 1.51 x BMI-0.70 x age - 3.6 x sex + 1.4 (R2 0.38, SE of estimate (SEE) 4.4% BF%). In adults the prediction formula was: BF% = 1.20 x BMI + 0.23 x age - 10.8 x sex - 5.4 (R2 0.79, SEE = 4.1% BF%). Internal and external cross-validation of the prediction formulas showed that they gave valid estimates of body fat in males and females at all ages. In obese subjects however, the prediction formulas slightly overestimated the BF%. The prediction error is comparable to the prediction error obtained with other methods of estimating BF%, such as skinfold thickness measurements or bioelectrical impedance.

Haemodynamic, metabolic and endocrine effects of short-term dexfenfluramine treatment in young, obese women

Seventeen normotensive, premenopausal women were treated with the 5-hydroxytryptamine-reuptake inhibitor dexfenfluramine 30 mg per day, for 4 days in a randomised double-blind, cross-over, placebo controlled trial. Energy intake was held constant during the study as the aim was to study the endocrine and metabolic effects of dexfenfluramine dissociated from its weight-lowering properties. Body weight, blood glucose, plasma insulin, cholesterol triglycerides and C-peptide after an overnight fast and during an oral load of 100 g glucose did not change after dexfenfluramine compared to placebo. Supine and standing systolic and diastolic blood pressures were significantly decreased, while heart rate remained unchanged. Plasma noradrenaline and plasma renin were markedly reduced by dexfenfluramine, and cortisol, beta-endorphin and thyroid hormones were not changed. Thus, dexfenfluramine has a significant hypotensive effect in normotensive, obese women after 4 days of treatment, independent of a negative energy balance. This was associated with decreased circulating plasma noradrenaline, indicating decreased sympathetic nerve activity. Dexfenfluramine may be a candidate drug for longer-term trials in the treatment of primary hypertension associated with obesity.

Assessment of abdominal fat deposition in female cynomolgus monkeys

Computed tomography (CT) was used to assess abdominal fat distribution in adult, female cynomolgus macaques (Macaca fascicularis). The technique used was similar to that applied in human beings and allowed intra-abdominal, subcutaneous and total abdominal fat to be quantitated in 1 cm thick sections. Correlations between single scans and the average of scans at several levels ranged from r = 0.96 to r = 1.00, indicating that a single scan is representative of abdominal fat distribution. Significant positive correlations were found between body mass index (BMI) and intra-abdominal fat (r = 0.89), subcutaneous fat (r = 0.91) and total abdominal fat (r = 0.90). As BMI increased, fat was preferentially deposited subcutaneously versus intra-abdominally. A unique fat depot, not previously described, was identified dorso-laterally between the internal abdominal oblique and the transversalis muscle. This fat depot was also positively correlated with BMI (r = 0.79). These results indicate that CT can be used in cynomolgus monkeys to quantitate regional fat deposits and that these monkeys resemble human beings in their abdominal fat patterning.

Exercise and body composition

We assessed changes in body composition in 41 young adults who engaged in various exercise and/or training programs on ad libitum diets. Most of those who gained weight sustained an increase in lean body mass (LBM), and most of those who lost weight lost LBM as well as fat. The change in LBM was directly related to the change in weight, with a regression slope of 0.500. An analysis of published data confirms these findings and, in concert with our data, provides the additional information that the magnitude of the change in body composition in exercising individuals is influenced by body fat content, just as it is for nonexercising individuals.

Body fat in lean and overweight women estimated by six methods

Body fat content of seven lean women (body mass index (BMI) 20.6 (SD 1.8) kg/m2) and seven overweight women (BMI 31.1 (SD 3.3) kg/m2) was estimated by six different methods: underwater weighing (UWW), body-water dilution (BWD), whole-body counting (40K), skinfold thickness (SFT), bioelectrical impedance (BEI) and magnetic resonance imaging (MRI). Using UWW as the reference method, the differences between percentage fat by each other method and the percentage fat by UWW were calculated for each subject. The mean difference was lowest for SFT and highest for BWD. MRI showed the lowest variability in individual results, and 40K the highest. 40K and BWD methods used in combination gave better agreement with UWW results than either 40K or BWD methods alone. There was a weak negative correlation between the difference from the UWW results and percentage fat in the SFT measurements, but not in the BWD, 40K, BEI or MRI measurements, suggesting that for these methods the assumptions involved produced no greater inaccuracy in the overweight women than in the lean women. In all subjects the BEI offered little improvement over the traditional SFT measurements. The agreement between MRI and UWW estimates in both lean and overweight women suggests that MRI may be a satisfactory substitute for the more established methods of body fat estimation in adult women.

An evaluation of waist to hip ratio measurement methods in relation to lipid and carbohydrate metabolism in men

The purpose of this study was to determine which method of measuring waist to hip ratio (WHR) was the most effective in assessing decrements associated with an abdominal fat distribution in 46 non-obese, middle to older aged men (mean +/- s.e., age 52.8 +/- 0.88 years; body fat 19.7 +/- 0.72 percent). Circumferences were obtained at the following sites and WHR calculated (waist circumference/hip circumference): (1) minimal waist/maximal hip; (2) level of umbilicus/maximal hip; (3) level of umbilicus/level of greater trochanters; (4) level of umbilicus/level of superior iliac spine; and (5) level of 1/3 of the distance between the xiphiod process and umbilicus/level 4 cm below the superior iliac spine. Significant (P less than 0.05) associations were observed for measurement methods 1, 2 and 3 with indices of lipid and carbohydrate metabolism, body composition, and fitness level. Measurement method 5 was not related to any metabolic or physiological variables, while measurement method 4 was intermediate in terms of the strength of the associations. These findings suggest that the predictive strength of WHR can vary depending upon the measurement method used.

High sucrose diet increases visceral fat accumulation in VMH-lesioned obese rats

We have previously reported that metabolic abnormalities in obese subjects are closely related to intraabdominal fat accumulation. In order to clarify the causal relationship between high sucrose intake and intraabdominal visceral fat accumulation, the effects of a high sucrose diet on mesenteric fat weight, fasting plasma glucose (FPG) and triglyceride (TG) levels were investigated in bilateral ventromedial hypothalamic-lesioned obese rats (VMH) and control rats (control). The mesenteric fat weight (g)/abdominal subcutaneous fat weight (g) (M/S ratio), a parameter of visceral fat accumulation, was significantly higher in a high sucrose diet fed group (HSD group) (VMH 1.94 +/- 0.71, control 1.63 +/- 0.28) than in a lab chow fed group (LC group) (VMH 1.30 +/- 0.31, control 1.27 +/- 0.33) (P less than 0.01). In addition, the fat cell volume of mesenteric fat deposits was significantly greater in the HSD group (VMH 1.17 +/- 0.26 nl, control 0.24 +/- 0.10 nl) than in the LC group (VMH 0.74 +/- 0.27 nl, control 0.14 +/- 0.07 nl) (P less than 0.001), although the fat cell number did not differ among any experimental rat groups. FPG and TG levels were higher in the HSD group than in the LC group in VMH-lesioned rats, and a significant correlation was observed between mesenteric fat volume and FPG levels (VMH r = 0.58, P less than 0.05; control r = 0.50, P less than 0.05) as well as between mesenteric fat volume and TG levels (VMH r = 0.49, P less than 0.05; control r = 0.56, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise on energy balance in meal-fed mice

The effects of exercise on energy balance have been investigated in mice accustomed to eating their daily food ration in three meals. A meal period lasts 1 hour, and during that period mice were allowed to eat unrestrictedly a pelleted stock diet. Two series of experiments were conducted. In one series of experiments indirect calorimetric measurements were carried out in untrained mice that were assigned to 3 experimental groups; a first group of mice was allowed to rest; a second group of mice was exercised immediately before one of the 3 meals; a third group of mice was exercised immediately after one of the 3 meals. The exercise bout consisted of 1 hour of forced exercise on a rodent treadmill at a speed of 20 meters per minute. O2 consumption (VO2) and CO2 production were monitored throughout a full day except at the time the exercising animals were on the treadmill. In a second series of experiments long-term energy balance measurements were carried out. Mice were then assigned to experimental conditions similar to those previously described for 31 days during which period food intake and body weight were continuously monitored. At the end of 31 days of experiment, mice were killed, and their carcasses were individually analysed for their contents of energy, fat and protein. Carcass and food gross energy contents were assessed by bomb calorimetry. At the end of the long-term energy balance trial, the percentage of fat, the energy gain, the energy density and the weight of the dry carcass were significantly lower in exercised groups of mice than in the resting group of animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, insulin-like growth factor-I and growth of lambs

The effect on young lambs of 0.25 mg recombinant bovine GH (bGH)/kg per day on plasma concentrations of insulin-like growth factor-I (IGF-I), glucose, specific hepatic GH binding and body composition changes was examined at two levels of nutrition (lucerne pellets; 3 and 1.7% of body weight/day). Lambs on low levels of nutrition had low plasma IGF-I (P less than 0.001). Plasma concentrations of IGF-I were increased by bGH treatment at both levels of nutrition, with the high nutrition group showing the greatest IGF-I response after 3 and 40 days of bGH treatment. Plasma glucose, after 40 days, was higher overall (P less than 0.05) in lambs on high nutrition. bGH treatment increased plasma glucose, with the response being greater in the well-fed lambs. Specific binding of GH to liver membranes was highest in lambs on high nutrition and on bGH treatment; no significant interaction between nutrition and bGH treatment was detected, indicating that specific binding of GH was increased proportionally by bGH at both nutritional levels. The major change in body composition was the reduced level of fatness in lambs treated with bGH. There was no significant effect of bGH on body weight although bGH treatment tended to increase weight gain of well-fed lambs and decreased weight loss of poorly nourished lambs. The results show that, although there was a significant (P less than 0.05) bGH/nutrition interaction for IGF-I there was no such interaction for body weight/components or specific GH binding to the liver. The results indicate that an increase in plasma IGF-I does not necessarily result in increases in growth or changes in carcass composition.

Suppression of natural killer cell activity by ethanol consumption and food restriction

Effects of 4-week food restriction and ethanol consumption on natural killer (NK) cell activity and carcass composition were evaluated. Female, C57BL/6 mice given water (H2O) or ethanol (20% w/v, ETOH) ad libitum were placed in one of three dietary groups: unrestricted (UNR), moderately restricted (MR, 2.2 g/day), or severely restricted (SR, 1.8 g/day). Food restriction alone (MR, SR) significantly reduced body, spleen, and thymus weights; carcass lipid content (SR only); spleen cell number; and baseline and interleukin-2 (rIL-2) stimulated NK cell activities. Ethanol consumption was unaffected by food restriction and in restricted mice it did not suppress food intake. Thus, average calories derived from ethanol increased from 30% (UNR) to 40% (SR) with the degree of food restriction in these groups. Mice given ethanol and restricted food intake had at least as heavy or heavier body, spleen, and thymus weights than water-drinking (H2O) counterparts. Spleen cell number was reduced in ethanol-consuming (ETOH), food restricted groups compared with UNR H2O control. Baseline NK cell activity was suppressed 50% to 90% in all ETOH and food-restricted groups. rIL-2 stimulated NK cell activity was suppressed 18% to 76% in food restricted mice independent of ethanol intake. These results indicate that supplementary ethanol calories did not enhance NK cell activity in UNR ETOH mice, nor did they protect splenic NK cell activity from the suppressant effects of food restriction. Ethanol consumption significantly increased carcass lipid content in all groups compared with their H2O counterparts. This increase was largely responsible for the preservation of body weight in ETOH mice especially during food restriction.

Lean tissue mass is a useful predictor of induction dose requirements for propofol

The effect of age and sex on ED50 values for propofol was studied in 92 patients aged between 16 and 85 years. All doses were based on lean tissue mass (LTM). The end-point for loss of consciousness was loss of the ability to hold a light object. The mean of the ED50 values for males was 1.31 mg.kg LTM-1 and for females 1.28 mg.kg LTM-1. For males the ED50 values ranged from 0.94 to 1.69 mg.kg LTM-1. For females, the range was 1.06-1.57 mg.kg LTM-1. On statistical analysis, these differences were not significant. These data contrast with other studies in which dosage was based on total body mass where a decrease in dose requirement with age was demonstrated. We propose that by using lean tissue mass to calculate dosage, considerable normalisation of patient response can be achieved. There is considerable inter-individual variation in response to propofol. Age is less important than this variation in determining the correct dose for each patient, provided doses are based on LTM.

Biochemical cost of a fight in fed and fasted Betta splendens

Behavioral and biochemical effects of threat displays and fights were determined in both fed and fasted animals. A week-long fast resulted in subtle behavioral modifications and a significant reduction in muscle glycogen. Threat displays had no effect on carcass composition. In the course of fighting, fed animals degraded large amounts of lipids, glycogen and amino acids, while fasted animals degraded only glycogen. Two alternative hypotheses are proposed to explain the difference between the biochemical effects of a fight in fed and starved animals.

Body composition and sleeping metabolic rate in response to a 5-month endurance-training programme in adults

This study examined the effect of exercise training on body composition and sleeping metabolic rate (SMR) in 15 men and 13 women who participated in a 20-week training programme aimed at running a half marathon. Body mass (BM) was measured after waking up, fasted and with an empty bladder. Body composition was assessed using densitometry. The SMR was measured from 0300-0600 hours during an overnight sleep in a respiration chamber. Assessment of SMR was at least 36 h after the last period of exercise training. After 20 weeks of endurance training no change in BM was observed. However, body composition changed significantly. On average men lost 2.4 kg body fat (P less than 0.01) and gained 1.7 kg fat free mass (FFM) (P less than 0.01). In women fat loss averaged 0.9 kg after 20 weeks (P less than 0.01), while FFM increased by 1.0 kg (P less than 0.05). Loss of fat mass was significantly larger in males (P less than 0.05). No changes in SMR were found, either in absolute terms, or when normalised for BM or FFM. Therefore, we have concluded that exercise training has no chronic, long-term effect on SMR. A possible explanation for this outcome in view of the different findings in similar studies is discussed.

Effects of ambient temperature and body fat content on maternal litter reduction in Syrian hamsters

Reproduction in Syrian hamsters is sensitive to the general availability of metabolic energy. For example, females often modify their litter size by cannibalism on days 1-7 postpartum, and the number of young eaten is a function of the total supply of metabolic energy as determined by both food supply and body fat content. If the level of cannibalism is a function of energy availability, it might be expected that a drop in ambient temperature would increase cannibalism, since cold acclimation demands greater energy expenditure. We found that hamsters ate significantly more of their offspring when housed at 10 compared to 22 degrees C during lactation. The effect of cold on cannibalism was attenuated in hamsters fattened prior to cold exposure and exaggerated in hamsters that were lean prior to cold exposure. Thus, the litter size maintained by Syrian hamsters is a function of the total supply of metabolic fuels as determined by energy sources, such as food supply and adipose tissue, and by energetic costs of thermoregulatory and other processes.

Body composition in hypertensive elderly and middle-aged patients

The occurrence of hypertension, leading to various life-threatening complications in the elderly is a widely recognized problem. The changes of body composition were determined in 120 control and untreated hypertensive subjects of various ages. In middle-aged hypertensive males, the total blood volume and plasma volume increased significantly compared to those of the healthy controls, while this increase was not significant in the case of hypertensive middle-aged females. In contrast, in the elderly hypertensive male subjects, the volume of all fluid components decreased, except the total body fat and the vascular volumes. There was a slight, statistically non-significant, increase in all the vascular volumes except in the red cell mass. The elderly hypertensive females showed the same tendency compared to the healthy controls of the same age. The vascular compartments seem to be decreased in elderly males, compared to those of the middle-aged males, while slightly increased in elderly females.

Perioperative monitoring of total body water by bio-electrical impedance in children undergoing open heart surgery

Knowledge of the changes in total body water (TBW) following cardiac surgery (OHS) in children would be of value in fluid therapy and in researching the causes and management of capillary leak. We have validated a bioelectrical impedance technique (BEI) for non-invasive estimation of TBW in children after OHS. We report the use of this method in a longitudinal study. Twenty patients (mean age 4.7 years +/- 3.5 (SD), mean weight (WT) 16.2 kg +/- 1 kg) undergoing a variety of complex OHS procedures were studied from 1 day preoperatively to 4 days postoperatively. Anaesthetic and basic bypass (CPB) techniques were uniform. Six patients underwent CPB at less than 20 degrees C, 10 at 20 degrees - 25 degrees C and 4 at 26 degrees - 33 degrees C. TBW (BEI), core (ctemp) and peripheral (ptemp) temperatures and fluid balance (TFB) were recorded at frequent intervals. TBW (by BEI) rose (P less than 0.001) following CPB in all patients from 62% +/- 9% (SD) body weight preoperatively to 73% +/- 13% in the ICU (an increase of 11% +/- 5%). TBW remained significantly elevated until the 3rd postoperative day. Multivariate analysis (MVA) confirmed that TBW was significantly related to TFB, but not to ctemp or ptemp. MVA also revealed smaller patient size (height and weight), younger age and longer CPB time as incremental risk factors for the rise in TBW.

CONCLUSIONS

(1) BEI permits the non-invasive study of TBW in children after OHS, when TBW variation may be considerable. (2) The smaller the child and the longer the CPB, the greater the rise in TBW. (3) The technique should be a valuable tool in researching the major water fluxes associated with CPB in children.

[Effect of sports on the distribution of body fat]

The pathogenetic effectiveness of the risk factor overweight is essentially modified by the distribution of the fatty depot. The form of obesity, the primary obesity, which above all is to be found in men is connected with a relatively high risk for the appearance and progression of several chronic diseases which at present determine morbidity. An only two-hour sports activity per week has a great influence on the size and the distribution of the lipopexia. Sporting persons have less body fat than inactive ones. In particular in sporting males the deposition of fat in the abdominal region is much limited.

Diet composition determines course of hyperphagia in developing Zucker obese rats

Previous observations from this laboratory indicate that, during growth, the hyperphagia of the male genetically obese Zucker rat reaches a peak or "breakpoint" and then declines. To examine the effect of dietary macronutrient content on the course of hyperphagia, groups of male lean and obese rats were maintained from 5-28 weeks of age on powdered chow, or isocaloric diets (3.6 kcal/g) containing 72% of calories as corn oil, dextrose, or soy isolate protein (n = 5 lean and obese rats/diet). On chow, hyperphagia was maintained at a level of 7-8 g above lean control intake until a "breakpoint" was reached at 17 weeks, and obese intake declined to lean control level. On the fat diet, hyperphagia was increased to 10 g/day when a breakpoint was reached at 8 weeks. On the dextrose and protein diets, hyperphagia at a level of 3-4 g/day reached breakpoints at weeks 18 and 16, respectively. On all diets, the intakes of obese rats were precisely equal to the intakes of lean control rats by weeks 19-20. These data show that the magnitude and duration of hyperphagia in the developing obese rat are influenced by diet composition. Previously, we have proposed that the obese rat's hyperphagia arises from rapid adipocyte filling. Since high-fat diets facilitate adipocyte enlargement, the early "breakpoint" of hyperphagia seen with the high-fat diet may indicate that this feeding stimulation decreases as the fat cells of the obese rat approach maximal size.

Body composition alterations consequent to an exercise program for pre and postmenopausal women

The purposes of this study were: (a) to evaluate the effects of an exercise program upon the body composition of premenopausal (no. 43) and postmenopausal (no. 66) women, aged 35-70 years, and (b) to compare exercise Ss with age matched control Ss. Body composition was assessed by skinfold measurement and hydrostatic weighing. Exercise Ss walked or jogged and performed light resistive exercise for 60 minutes per day three times per week for 24 weeks. Control Ss remained sedentary. ANOVAs revealed: (a) no significant (p greater than or equal to .05) differences in exercise training effects between premenopausal and postmenopausal Ss, and (b) exercise Ss exhibited less body fatness while control Ss possessed more body fat as represented by significant changes (p less than or equal to .05) for the exercise and control Ss, respectively in: body density (+.002 g/cc, -.001 g/cc); % fat (-1.2%, +.6%); fat weight (-.4 kg, +1.1 kg); suprailiac skinfold (-.3 mm, +7 mm); and abdominal skinfold (-.3 mm, +1.5 mm). It was concluded that: (a) menopausal status did not alter the effects of exercise in this study, and (b) exercise training produced a positive effect in the exercise Ss by reversing body composition trends associated with a sedentary lifestyle.

A physiological comparison of female body builders and power lifters

Ten female body builders (FBB) (X age +/- SD = 30.40 +/- 8.22 years) and ten female power lifters (FPL) (X age +/- SD = 25.20 +/- 6.01 years) were studied to determine group differences in body composition, strength and anaerobic characteristics. All subjects had been training a minimum of two years and twelve of the subjects had competed nationally while the remainder had participated in regional or local events. Measures of body build and body composition were obtained via hydrostatic weighing, skinfolds (sum of 7), circumferences (sum of 13) and diameters (sum of 9). Flexion and extension strength of the dominant forearm and leg were measured with a Cybex II dynamometer at 60 degrees/second. Anaerobic power and capacity were determined using the Wingate Anaerobic Test. Independent t-tests indicated the FPL had significantly greater body weight (X +/- SD = 68.60 +/- 3.60 vs 56.47 +/- 0.85 kg), relative fat (21.47 +/- 1.29 vs 13.51 +/- 1.46%), sum of skinfolds (120.76 +/- 7.55 vs 71.46 +/- 7.02 mm), sum of diameters (177.57 +/- 2.97 vs 168.17 +/- 2.55 cm), and sum of circumferences (594.93 +/- 13.10 vs 551.24 +/- 3.17). No significant differences were found for fat-free weight, strength or anaerobic power and capacity. These results demonstrate subtle but specific differences between well-trained FBB and FPL reflecting the leaner physiques and smaller skeletal structures of the FBB necessary for the definition and symmetry demanded by the sport. The lack of differences in strength and anaerobic characteristics reflect the similarity of the groups in basic training techniques.

Somatic, endocrine and metabolic changes in controls pair-fed for six weeks to rats with dorsomedial hypothalamic nucleus lesions (DMNL rats)

One group of weanling male Sprague-Dawley rats received lesions in the dorsomedial hypothalamic nuclei (DMNL rats), whereas two additional groups of rats were sham-operated (CON). One of these CON groups was allowed to feed ad lib (CON-ADLIB) while the other CON group was pair-fed for 6 weeks to the DMNL rats (CON-PF). Despite eating the same amount of food as DMNL rats. CON-PF animals had consistently lower body weights and also utilized food energy more poorly than DMNL rats. The CON-PF group also had smaller kidneys and less percent liver protein but more epididymal fat pad percent protein than DMNL rats. Whereas plasma glucose concentrations were comparable among the three groups, insulin levels were significantly higher, and free fatty acid levels lower in CON-PF than in DMNL rats. The CON-PF group incorporated less glucose-U-C14 carbon into liver glycogen but more of the tracer into liver lipid than the DMNL group. Glucose carbon was also incorporated more avidly into epididymal fat pad lipid by CON-PF than by DMNL rats. The data not only confirm previous findings in DMNL rats but in addition show that the neurologically intact rats fed the same amount of food that is eaten spontaneously by DMNL rats show somatic and metabolic alterations that suggest that they cannot cope with this low amount of substrate. The normalcy of the DMNL rats, compared to ad lib-fed sham-operated controls, in all metabolic parameters suggests that the low food intake is indeed "normal" for this preparation and may be the reflection of an "organismic" set point.

Ovariectomy accelerates the growth of microscopic hepatocellular neoplasms in the mouse: possible association with whole body growth and fat deposition

Ovariectomy (ovex) shortens the latency for development of hepatocellular neoplasms in mice, but the mechanism by which this occurs is not known. In the present study, B6C3F1 mice were given single i.p. injections of diethylnitrosamine (5 mg/kg) when they were 15 days old and either ovexed or sham operated 7 weeks later. Groups of 6 to 8 mice were killed after an additional 8, 14, 20, and 26 weeks. Four ovexed and four sham-operated mice were also killed after 56 weeks. By 8 weeks after surgery, the fractional volume of microscopic liver neoplasms in the ovexed mice was 4.3 times greater than in the shams and ablation had caused a 27% greater gain in body weight. During the following 18 weeks, tumor burdens were 3.9 to 10.6 times greater in ovexed than in the sham-operated mice and the rates of weight gain were similar in the two groups. Stereological analysis indicated that ovexed animals had more tumors than sham-operated animals, 575 versus 234/liver at 8 weeks and 952 versus 724/liver at 14 weeks after surgery. The ovex-induced increase in the number of neoplasms was spread throughout most of the size classes at both times; however, the impact on tumor burden of a small number of large tumors was only apparent at 14 weeks, when 8% of them accounted for more than two thirds of the aggregate tumor volume. The effect of the early emergence of these more rapidly growing tumors was also obvious at 1 year, when the livers of ovexed mice were more than twice the size of the shams (5.1 versus 1.8 g) and they contained 4 times as many tumors larger than 1 cm in diameter than the shams (2 versus 0.5/mouse). Since these very large tumors were invariably, at least partially, composed of trabecular hepatocellular carcinoma, ovariectomy appears to have also fostered tumor progression. The time course of ovex-stimulated weight gain and the manner in which it affected body composition were also analyzed. Eight days following ovex, the rate of weight gain abruptly increased. The acceleration persisted for only 14 days, after which it leveled off at body weights that were 24% higher than in sham-operated mice. The difference in weights resulted from 2.5 times more fat and 10% more protein in the carcasses of ovexed than sham-operated mice. This study identifies an early 8-week period in which hormonal changes resulting from ovex maximally stimulate the growth of liver tumors.(ABSTRACT TRUNCATED AT 400 WORDS)