Survival and body composition of normal and hypothalamic obese rats in acute starvation

1960 ◽  
Vol 198 (4) ◽  
pp. 757-761 ◽  
Author(s):  
D. G. Montemurro ◽  
J. A. F. Stevenson
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Fat Free Mass ◽  
Prolonged Survival ◽  
Metabolic Rates ◽  
Total Water ◽  
Fed State ◽  
Normal Limits ◽  
Obese Rats ◽  
Acute Starvation

Female hypothalamic obese rats contained approximately 240% more fat, 10% more protein and 18% more water than did their controls, however ratio total water/fat-free mass remained within normal limits in this frank obesity. At death from starvation, the water, fat-free mass and protein compartments were significantly smaller than those of the controls, the fat compartments were not significantly different. Control rats survived starvation for 16.4 ± 1.3 days, obese rats 42.7 ± 1.8 days ( P < .001). The resting metabolic rates of normal and obese rats in the fed state were not different and both fell gradually throughout starvation. The prolonged survival of obese rats is due primarily to their excess reserve of energy and not to alterations in metabolic rate. As in the fed state, hypothalamic obese rats drank less water during starvation than did the controls. This is thought to result from direct interference with hypothalamic elements regulating thirst and the spontaneous consumption of water.

Effect of age on body composition and resting metabolic rate

1990 ◽  
Vol 259 (2) ◽  
pp. E233-E238 ◽  
Author(s):  
N. K. Fukagawa ◽  
L. G. Bandini ◽  
J. B. Young
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Isotope Dilution ◽  
Resting Metabolic Rate ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Open Circuit ◽  
Fat Free Mass ◽  
The Difference ◽  
Old Men

The relationship between fat-free mass (FFM) and resting metabolic rate (RMR) was compared in young men (n = 24; age 18-33 yr), old men (n = 24; 69-89 yr), and old women (n = 20; 67-75 yr). Body composition was assessed using anthropometry, bioelectrical impedance analysis (BIA), and isotope dilution with 18O-labeled water. RMR was measured at least twice using an open-circuit indirect calorimetry system with a ventilated hood. The results indicate that the different methods for assessing body composition vary substantially and should not be used interchangeably. Anthropometry was not adequate to assess group differences in body fatness, although skinfold measures may be appropriate for within-group comparisons. BIA correlated well with the isotope-dilution technique and may be a useful measure of FFM. Finally, RMR was lower in the old men than the young (1.04 +/- 0.02 vs. 1.24 +/- 0.03 kcal/min, P less than 0.001) and remained lower even when adjusted for FFM estimated by isotope dilution (P less than 0.001). RMR in the women was also lower (0.84 +/- 0.02 kcal/min), but in contrast to the difference between young and old men, RMR adjusted for FFM did not differ (P = 0.16) between old men and women. Therefore, it is clear that differences in FFM cannot fully account for the lower RMR in the old, suggesting that aging is associated with an alteration in tissue energy metabolism.

scholarly journals Seasonal variation in sleeping metabolic rate, thyroid activity, and leptin

2003 ◽  
Vol 285 (2) ◽  
pp. E338-E343 ◽  
Author(s):  
Guy Plasqui ◽  
Arnold D. M. Kester ◽  
Klaas R. Westerterp
Keyword(s):  
Body Composition ◽  
Seasonal Variation ◽  
Metabolic Rate ◽  
Compartment Model ◽  
Fat Free Mass ◽  
Interindividual Variation ◽  
Dilution Method ◽  
Thyroid Activity ◽  
Intraindividual Variation ◽  
Total Thyroxine

We investigated seasonal variation in sleeping metabolic rate (SMR) and the possible relation to body composition, thyroid activity, and leptin. Twenty-five healthy volunteers were examined four times during the year: in spring (April, May), summer (July, August), autumn (October, November), and winter (January, February). Body composition was determined using a three-compartment model based on underwater weighing and the deuterium dilution method. SMR was measured during an overnight stay in a respiration chamber. A blood sample was taken for the analysis of free and total thyroxine, TSH, and leptin. SMR showed a significant seasonal variation ( P < 0.01) with a maximum in winter (4.54 kJ/min) and a minimum in summer (4.34 kJ/min). The amplitude was 0.10 ± 0.02 kJ/min, and the phase was November 5th. Season explained 17% of the intraindividual variation in SMR. The circannual rhythm in SMR could not be explained by changes in body composition, thyroid activity, or leptin. Interindividual variation in SMR was explained by fat-free mass ( P < 0.001) and leptin ( P < 0.001).

Resting metabolic rate is lower in women than in men

1993 ◽  
Vol 75 (6) ◽  
pp. 2514-2520 ◽  
Author(s):  
P. J. Arciero ◽  
M. I. Goran ◽  
E. T. Poehlman
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Fat Mass ◽  
Aerobic Fitness ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Peak Oxygen Consumption ◽  
Activity Peak ◽  
Peak Vo2 ◽  
And Gender

This study examined gender differences in resting metabolic rate (RMR) across a broad age spectrum after controlling for differences in body composition and aerobic fitness. Three hundred twenty-eight healthy men (17–80 yr) and 194 women (18–81 yr) volunteers were characterized for RMR, body composition, physical activity, peak oxygen consumption (peak VO2), anthropometrics, and energy intake. Measured RMR was 23% higher (P < 0.01) in men (1,740 +/- 194 kcal/day) than in women (1,348 +/- 125 kcal/day). Multiple regression analysis showed that 84% of individual variation in RMR was explained by fat-free mass, fat mass, peak VO2, and gender. After controlling for differences in fat-free mass, fat mass, and peak VO2, a lower RMR (3%; P < 0.01) persisted in women (1,563 +/- 153 kcal/day) compared with men (1,613 +/- 127 kcal/day). Adjusted RMR in premenopausal (P < 0.01) and postmenopausal (P < 0.05) women was lower than in men of a similar age. Our results support a lower RMR in women than in men that is independent of differences in body composition and aerobic fitness.

scholarly journals Impact of indexing resting metabolic rate against fat-free mass determined by different body composition models

2004 ◽  
Vol 58 (8) ◽  
pp. 1132-1141 ◽  
Author(s):  
J LaForgia ◽  
GE van der Ploeg ◽  
RT Withers ◽  
SM Gunn ◽  
AG Brooks ◽  
...  
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Fat Free Mass

scholarly journals Effects of obesity and sex on the energetic cost and preferred speed of walking

2006 ◽  
Vol 100 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Raymond C. Browning ◽  
Emily A. Baker ◽  
Jessica A. Herron ◽  
Rodger Kram
Keyword(s):  
Body Composition ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Mass Distribution ◽  
Energy Cost ◽  
Walking Speed ◽  
Normal Weight ◽  
Metabolic Rates ◽  
Obese Women ◽  
Gross Energy

The metabolic energy cost of walking is determined, to a large degree, by body mass, but it is not clear how body composition and mass distribution influence this cost. We tested the hypothesis that walking would be most expensive for obese women compared with obese men and normal-weight women and men. Furthermore, we hypothesized that for all groups, preferred walking speed would correspond to the speed that minimized the gross energy cost per distance. We measured body composition, maximal oxygen consumption, and preferred walking speed of 39 (19 class II obese, 20 normal weight) women and men. We also measured oxygen consumption and carbon dioxide production while the subjects walked on a level treadmill at six speeds (0.50–1.75 m/s). Both obesity and sex affected the net metabolic rate (W/kg) of walking. Net metabolic rates of obese subjects were only ∼10% greater (per kg) than for normal-weight subjects, and net metabolic rates for women were ∼10% greater than for men. The increase in net metabolic rate at faster walking speeds was greatest in obese women compared with the other groups. Preferred walking speed was not different across groups (1.42 m/s) and was near the speed that minimized gross energy cost per distance. Surprisingly, mass distribution (thigh mass/body mass) was not related to net metabolic rate, but body composition (% fat) was ( r2 = 0.43). Detailed biomechanical studies of walking are needed to investigate whether obese individuals adopt novel energy saving mechanisms during walking.

scholarly journals Short-term captivity influences maximal cold-induced metabolic rates and their repeatability in summer-acclimatized American goldfinches Spinus tristis

2013 ◽  
Vol 59 (4) ◽  
pp. 439-448 ◽  
Author(s):  
David L. Swanson ◽  
Marisa O. King
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Muscle Growth ◽  
Metabolic Responses ◽  
Phenotypic Flexibility ◽  
Metabolic Rates ◽  
Wild Populations ◽  
Short Term ◽  
Fitness Consequences ◽  
Metabolic Variation

Abstract Studies of metabolic variation in birds have involved both wild and captive individuals, but few studies have investigated whether captivity directly influences metabolic rates, despite such variation potentially confounding conclusions regarding how metabolic rates respond to the conditions under study. In addition, whether short-term captivity influences metabolic rate repeatability in birds is currently uninvestigated. In this study, we measured Msum (maximal cold-induced metabolic rates) in summer acclimatized American goldfinches Spinus tristis directly after capture from wild populations, after approximately 2 weeks of indoor captivity (Captive 1), and again after an additional 1–2 weeks of captivity (Captive 2). Msum increased significantly (16.9%) following the initial captive period, but remained stable thereafter. Body mass (Mb) also increased significantly (9.2%) during the initial captive period but remained stable thereafter, suggesting that muscle growth and/or remodeling of body composition produced the observed metabolic variation. Mb and Msum were not significantly repeatable between wild and Captive 1 birds, but were significantly repeatable between Captive 1 and Captive 2 groups. These data suggest that caution must be exercised when extrapolating metabolic rates from short-term captive to wild populations. In addition, Msum was a repeatable trait for birds under conditions where mean metabolic rates remained stable, but Msum repeatability disappeared during acclimation to conditions promoting phenotypically flexible metabolic responses. This suggests that the capacity for phenotypic flexibility varies among individuals, and such variation could have fitness consequences.

Does menarche mark a period of elevated resting metabolic rate?

2004 ◽  
Vol 286 (3) ◽  
pp. E456-E462 ◽  
Author(s):  
Jennifer L. Spadano ◽  
Linda G. Bandini ◽  
Aviva Must ◽  
Gerard E. Dallal ◽  
William H. Dietz
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Fat Mass ◽  
Resting Metabolic Rate ◽  
Tanner Stage ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Time Points ◽  
Stage 1

Resting metabolic rate (RMR) and body composition were measured in 44 initially nonoverweight girls at three time points relative to menarche: premenarche (Tanner stage 1 or 2), menarche (±6 mo), and 4 yr after menarche. Mean absolute RMR was 1,167, 1,418, and 1,347 kcal/day, respectively. Absolute RMR was statistically significantly higher at menarche than at 4 yr after menarche despite statistically significantly less fat-free mass (FFM) and fat mass (FM), suggesting an elevation in RMR around the time of menarche. The pattern of change in RMR, adjusted for FFM, log transformed FM, age, race, parental overweight, and two interactions (visit by parental overweight, parental overweight by FFM), was also considered. Adjusted RMR did not differ statistically between the visits for girls with two normal-weight parents. For girls with at least one overweight parent, adjusted RMR was statistically significantly lower 4 yr after menarche than at premenarche or menarche. Thus parental overweight may influence changes that occur in RMR during adolescence in girls.

scholarly journals Body composition and basal metabolic rate in pregnant women

2013 ◽  
Vol 76 (2) ◽  
pp. 163-171
Author(s):  
Shaila Bhardwaj ◽  
Deepali Verma ◽  
Satwanti Kapoor
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Longitudinal Design ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Fat Free Mass ◽  
Metabolic Adaptation ◽  
Cross Sectional ◽  
The Relationship

Abstract Pregnancy, a milieu of physiological and metabolic adaptation, is associated with enhanced basal metabolic rate by alteration in maternal tissue and metabolism to ensure foetal growth and development. A cross-sectional study of Indian Baniya females was conducted to assess the relationship between basal metabolic rate and body composition during pregnancy. The 20-40 year old female subjects were broadly categorized in two groups; pregnant (N=198) and non-pregnant (N=35).Anthropometric measurements of each subject included height and weight, with basal metabolic rate (BMR), fat mass (FM), fat-free mass (FFM) and total body water (TBW) assayed by bioelectric impedance body composition analyzer. The descriptive statistics revealed pregnancy associated weight gain, increased FFM, FM, TBW and BMR with marked changes during the second and third trimesters. Although multiple linear regression analysis showed substantial change in BMR due to both FM and FFM, fat-free mass contributed to a much lesser extent. Pregnancy, as an anabolic phase of the female reproductive cycle, is associated with metabolic flexibility which alters the relationship between body composition and BMR. These findings however require further validation in longitudinal design studies.

scholarly journals Resting metabolic rate, body composition, and serum leptin concentrations in a free-living elderly population

2000 ◽  
pp. 486-492 ◽  
Author(s):  
M Neuhauser-Berthold ◽  
BM Herbert ◽  
PM Luhrmann ◽  
AA Sultemeier ◽  
WF Blum ◽  
...  
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Body Fat ◽  
Resting Metabolic Rate ◽  
Bioelectrical Impedance ◽  
Fat Free Mass ◽  
Stepwise Multiple Regression ◽  
Impedance Method ◽  
Serum Leptin ◽  
Age Related

OBJECTIVE: The present study investigated the relationship between serum leptin concentrations and resting metabolic rate (RMR) in a large study group of elderly individuals with special consideration of body composition and body fat distribution as possible confounders. DESIGN AND METHODS: The subjects were 122 women (age: 69+/-6 years, body mass index (BMI): 26.3+/-3.6 kg/m(2)) and 82 men (age: 69+/-5 years, BMI: 26.0+/-2.6 kg/m(2)). RMR was measured by indirect calorimetry and body composition by the bioelectrical impedance method. Serum leptin levels were determined by radioimmunoassay. RESULTS: There was a strong correlation between fat mass (FM) and serum leptin levels in both sexes. An age-related decline in leptin levels adjusted for FM was observed only in the women. After adjustment of RMR for both fat-free mass (FFM) and FM, leptin levels were not associated with RMR. In stepwise multiple regression analysis, FFM was the main predictor of RMR, explaining 35.8% and 47.6% of the variance of RMR in men and women respectively. FM did not explain variance in RMR in men, but accounted for 2.6% of the variance in RMR in women. Waist-hip-ratio and age influenced RMR only in males, explaining 5.7% and 4.0% of the variance in RMR respectively. CONCLUSION: Leptin is not a significant predictor of RMR in the elderly, but body composition and distribution of body fat are significantly associated with RMR.

scholarly journals The effect of exercise and improved physical fitness on basal metabolic rate

1989 ◽  
Vol 61 (2) ◽  
pp. 155-173 ◽  
Author(s):  
S. A. Bingham ◽  
G. R. Goldberg ◽  
W. A. Coward ◽  
A. M. Prentice ◽  
J. H. Cummings
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Control Period ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Step Test ◽  
Doubly Labelled Water ◽  
Entire Study

1. The suggestion that there is a sustained enhancement in metabolic rate after exercise was investigated during the course of a study in which six normal-weight volunteers (three men, three women) took part in a 9-week training programme. Baseline values were assessed in a 3-5 week control period of minimal activity before training. At the end of the study the subjects were capable of running for I h/d, 5 d/week.2. Throughout the entire study the subjects were maintained on a constant diet. Measurement of energy expenditure by the doubly-labelled water (2H218O) method showed that the subjects had an energy imbalance of +3% in the control and -20% at the end of the training period. The subjects were in positive (1·1 (se 0·2) g) nitrogen balance in the second week of the control, and in negative (-0·6 (se 0·3) g) N balance in the last week of the exercise period.3. Over the course of the study maximum oxygen consumption (Vo2max) and high-density-lipoprotein-cholesterol levels increased by 30%. Heart rate at rest and when performing a standard step test fell significantly.4. Body composition was assessed weekly by40K counting and skinfold thickness measurements, in addition to2H2dilution at the beginning and end of the study. Fat-free mass was apparently gained in the early phases of the study, but there was lack of agreement between the different methods of assessing body composition. Changes in body-weight were not significant.5. Basal metabolic rate (BMR), overnight metabolic rate (OMR) and sleeping metabolic rate (SMR) were measured on three occasions: in the control period, and the beginning and end of the training periods. Average BMR in the control period was 5·91 (se 0·39) MJ/24 h and was not changed with activity. There were no changes in OMR (5·71 (se 0·27) MJ/24 h in the control) nor in SMR (5·18 (se 027) MJ/24 h in the control), nor in BMR, OMR or SMR when expressed per kg body-weight, or per kg fat-free mass.6. These results do not support the suggestion that there is a sustained increase in BMR following exercise that can usefully assist in weight-loss programmes.

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