scholarly journals The effects of physiological adaptations to calorie restriction on global cell proliferation rates

2011 ◽  
Vol 300 (4) ◽  
pp. E735-E745 ◽  
Author(s):  
Matthew D. Bruss ◽  
Airlia C. S. Thompson ◽  
Ishita Aggarwal ◽  
Cyrus F. Khambatta ◽  
Marc K. Hellerstein
Keyword(s):  
Cell Proliferation ◽  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Body Fat ◽  
Calorie Restriction ◽  
Percent Body Fat ◽  
Female Mice ◽  
Physiological Adaptations ◽  
Running Wheels

Calorie restriction (CR) reduces the rate of cell proliferation in mitotic tissues. It has been suggested that this reduction in cell proliferation may mediate CR-induced increases in longevity. However, the mechanisms that lead to CR-induced reductions in cell proliferation rates remain unclear. To evaluate the CR-induced physiological adaptations that may mediate reductions in cell proliferation rates, we altered housing temperature and access to voluntary running wheels to determine the effects of food intake, energy expenditure, percent body fat, and body weight on proliferation rates of keratinocytes, liver cells, mammary epithelial cells, and splenic T-cells in C57BL/6 mice. We found that ∼20% CR led to a reduction in cell proliferation rates in all cell types. However, lower cell proliferation rates were not observed with reductions in 1) food intake and energy expenditure in female mice housed at 27°C, 2) percent body fat in female mice provided running wheels, or 3) body weight in male mice provided running wheels compared with ad libitum-fed controls. In contrast, reductions in insulin-like growth factor I were associated with decreased cell proliferation rates. Taken together, these data suggest that CR-induced reductions in food intake, energy expenditure, percent body fat, and body weight do not account for the reductions in global cell proliferation rates observed in CR. In addition, these data are consistent with the hypothesis that reduced cell proliferation rates could be useful as a biomarker of interventions that increase longevity.

The Effects of Different Percentages of Dietary Fat Intake, Exercise, and Calorie Restriction on Body Composition and Body Weight in Obese Females

1994 ◽  
Vol 8 (6) ◽  
pp. 442-448 ◽  
Author(s):  
John J. Powell ◽  
Larry Tucker ◽  
A. Garth Fisher ◽  
Kim Wilcox
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Calorie Restriction ◽  
Dietary Fat ◽  
Fat Body ◽  
Caloric Intake ◽  
Dietary Fats ◽  
Percent Body Fat ◽  
Obese Women ◽  
Walking Program

Purpose. The goal of this study was to determine the effect of varying the amount of dietary fat, while holding calories at 1,200 kcals/day, on body weight and percent body fat in 35 obese women. Design. A pretest, midtest, posttest experimental design was employed, and subjects were randomly divided into one of four dietary fat groups, with 10%, 20%, 30%, or 40% of caloric intake as dietary fat. Intervention. Subjects consumed 1,200 kcals/day and a specified percentage of total energy as fat, depending on their dietary group. Protein was held constant at 20%. All subjects engaged in a five day/week walking program. Setting. Participants were recruited from the general community using newspaper advertisements. Subjects. Thirty-five obese women 25 to 45 years of age (means=38 ± 4.97) served as subjects. All were at least 20% above ideal weight and 30% to 52% body fat. Measures. Percent body fat, body weight, and anthropomorphic measurements were taken at baseline, six and 12 weeks. Dietary intake was recorded daily by each subject, and exercise walking logs were maintained by each participant. Results. All subjects lost body weight and body fat; however, there were no significant differences in the rate or amount of body weight or percent body fat lost across the four groups during the intervention. Conclusions. It appears that during calorie restriction and exercise for 12 weeks, percent of calories derived from dietary fats does not influence loss of body weight or percent body fat in adult obese women.

scholarly journals Severe protein deficiency induces hepatic expression and systemic level of FGF21 but inhibits its hypothalamic expression in growing rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Moro ◽  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Anne Blais ◽  
Julien Piedcoq ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Dietary Protein ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Growing Rats ◽  
Low Protein ◽  
Protein Diets

AbstractTo study, in young growing rats, the consequences of different levels of dietary protein deficiency on food intake, body weight, body composition, and energy balance and to assess the role of FGF21 in the adaptation to a low protein diet. Thirty-six weanling rats were fed diets containing 3%, 5%, 8%, 12%, 15% and 20% protein for three weeks. Body weight, food intake, energy expenditure and metabolic parameters were followed throughout this period. The very low-protein diets (3% and 5%) induced a large decrease in body weight gain and an increase in energy intake relative to body mass. No gain in fat mass was observed because energy expenditure increased in proportion to energy intake. As expected, Fgf21 expression in the liver and plasma FGF21 increased with low-protein diets, but Fgf21 expression in the hypothalamus decreased. Under low protein diets (3% and 5%), the increase in liver Fgf21 and the decrease of Fgf21 in the hypothalamus induced an increase in energy expenditure and the decrease in the satiety signal responsible for hyperphagia. Our results highlight that when dietary protein decreases below 8%, the liver detects the low protein diet and responds by activating synthesis and secretion of FGF21 in order to activate an endocrine signal that induces metabolic adaptation. The hypothalamus, in comparison, responds to protein deficiency when dietary protein decreases below 5%.

Protein appetite is increased after central leptin-induced fat depletion

2007 ◽  
Vol 293 (4) ◽  
pp. R1468-R1473 ◽  
Author(s):  
Michael F. Wiater ◽  
Bryan D. Hudson ◽  
Yvette Virgin ◽  
Sue Ritter
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Body Fat ◽  
Caloric Intake ◽  
Sprague Dawley ◽  
Body Protein ◽  
Macronutrient Selection ◽  
Daily Diet ◽  
Nadir Point ◽  
And Control

Leptin reduces body fat selectively, sparing body protein. Accordingly, during chronic leptin administration, food intake is suppressed, and body weight is reduced until body fat is depleted. Body weight then stabilizes at this fat-depleted nadir, while food intake returns to normal caloric levels, presumably in defense of energy and nutritional homeostasis. This model of leptin treatment offers the opportunity to examine controls of food intake that are independent of leptin's actions, and provides a window for examining the nature of feeding controls in a “fatless” animal. Here we evaluate macronutrient selection during this fat-depleted phase of leptin treatment. Adult, male Sprague-Dawley rats were maintained on standard pelleted rodent chow and given daily lateral ventricular injections of leptin or vehicle solution until body weight reached the nadir point and food intake returned to normal levels. Injections were then continued for 8 days, during which rats self-selected their daily diet from separate sources of carbohydrate, protein, and fat. Macronutrient choice differed profoundly in leptin and control rats. Leptin rats exhibited a dramatic increase in protein intake, whereas controls exhibited a strong carbohydrate preference. Fat intake did not differ between groups at any time during the 8-day test. Despite these dramatic differences in macronutrient selection, total daily caloric intake did not differ between groups except on day 2. Thus controls of food intake related to ongoing metabolic and nutritional requirements may supersede the negative feedback signals related to body fat stores.

Resistive training increases fat-free mass and maintains RMR despite weight loss in postmenopausal women

1995 ◽  
Vol 79 (3) ◽  
pp. 818-823 ◽  
Author(s):  
A. S. Ryan ◽  
R. E. Pratley ◽  
D. Elahi ◽  
A. P. Goldberg
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Postmenopausal Women ◽  
Body Fat ◽  
Fat Mass ◽  
Management Program ◽  
Fat Free Mass ◽  
Percent Body Fat ◽  
Plasma Norepinephrine ◽  
Resistive Training

Percent body fat increases with age and is often accompanied by a loss in muscle mass, strength, and energy expenditure. The effects of 16 wk of resistive training (RT) alone or with weight loss (RTWL) on strength (isokinetic dynamometer), body composition (dual-energy X-ray absorptiometry), resting metabolic rate (RMR) (indirect calorimetry), and sympathetic nervous system activity (catecholamines) were examined in 15 postmenopausal women (50–69 yr). RT resulted in significant improvements in upper and lower body strength in both groups (P < 0.01). The nonobese women in the RT group (n = 8) did not change their body weight or fat mass with training. In the obese RTWL group (n = 7), body weight, fat mass, and percent body fat were significantly decreased (P < 0.001). Fat-free mass and RMR significantly increased with training in both groups combined (P < 0.05). There were no significant changes in resting arterialized plasma norepinephrine or epinephrine levels in either group with training. RT increases strength with and without weight loss. Furthermore, RT and RTWL increase fat-free mass and RMR and decrease percent fat in postmenopausal women. Thus, RT may be a valuable component of an integrated weight management program in postmenopausal women.

Influence of Dietary Fat and Carbohydrate on Food Intake, Body Weight and Body Fat of Adult Dogs

1978 ◽  
Vol 157 (2) ◽  
pp. 278-281 ◽  
Author(s):  
D. R. Romsos ◽  
M. J. Hornshuh ◽  
G. A. Leveille
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Body Fat ◽  
Dietary Fat

Serum leptin levels and energy expenditure in normal weight women

1998 ◽  
Vol 76 (2) ◽  
pp. 237-241 ◽  
Author(s):  
L J Martin ◽  
PJH Jones ◽  
R V Considine ◽  
W Su ◽  
N F Boyd ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Food Intake ◽  
Energy Expenditure ◽  
Body Mass ◽  
Body Fat ◽  
Positive Association ◽  
Normal Weight ◽  
Serum Leptin ◽  
Percentage Body Fat ◽  
Healthy Humans

To investigate whether circulating leptin levels are associated with energy expenditure in healthy humans, doubly labeled water energy measurements and food intake assessment were carried out in 27 women (mean age, 48.6 years; weight, 61.9 kg; body mass index, 23.2). Energy expenditure was determined over 13 days. Food intake was measured by 7-day food records. Leptin was measured by radioimmunoassay. Leptin level was strongly associated with percentage body fat (r = 0.59; p < 0.001), fat mass (r = 0.60; p < 0.001), and body mass index (r = 0.41; p = 0.03), but no correlation was observed with energy expenditure (r = 0.02; p = 0.93). After controlling for percentage body fat, a positive association of leptin level with energy expenditure of marginal significance (p = 0.06) was observed. There were no significant univariate associations of age, physical activity, lean body mass, height, or dietary variables with leptin level. When controlling for body fat, a significant positive correlation was observed for percent energy from carbohydrate and negative correlations with dietary fat and alcohol intake. These findings confirm previous associations between leptin and body fat content and suggest a relationship between serum leptin and energy expenditure level in healthy humans.Key words: leptin, energy expenditure, body composition, diet.

Effect of (-)-hydroxycitrate on development of obesity in the Zucker obese rat

1981 ◽  
Vol 240 (1) ◽  
pp. E72-E78 ◽  
Author(s):  
M. R. Greenwood ◽  
M. P. Cleary ◽  
R. Gruen ◽  
D. Blase ◽  
J. S. Stern ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Cell Size ◽  
Treatment Period ◽  
Body Fat ◽  
Substantial Reduction ◽  
Female Rats ◽  
Fat Cell ◽  
Fat Cell Size ◽  
Obese Rats

Young Zucker lean (Fa/-) and obese (fa/fa) female rats were fed the fatty acid synthesis inhibitor (-)-hydroxy-citrate as a dietary admixture for 39 days. In the lean rats, (-)-hydroxycitrate treatment decreased body weight, food intake, percent of body fat, and fat cell size. In the obese rat, food intake and body weight were reduced but the percent of body fat remained unchanged. Throughout the treatment period, obese rats maintained a fat cell size equivalent to their obese controls. Although a reduction in fat cell number in the obese rats occurred during the treatment period, marked hyperplasia was observed during the posttreatment period. The results of this study indicate that the obese rat, despite a substantial reduction in body weight produced by (-)-hydroxycitrate, still defends its obese body composition.

scholarly journals Susceptibility to diet induced obesity at thermoneutral conditions is independent of UCP1

2021 ◽  
Author(s):  
Sebastian Dieckmann ◽  
Akim Strohmeyer ◽  
Monja Willershaeuser ◽  
Stefanie Maurer ◽  
Wolfgang Wurst ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Knockout Mice ◽  
Body Weight Gain ◽  
Uncoupling Protein ◽  
Exon 2 ◽  
Diet Induced Obesity ◽  
Brown Adipose ◽  
Knockout Model

Objective Activation of uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) upon cold stimulation leads to substantial increase in energy expenditure to defend body temperature. Increases in energy expenditure after a high caloric food intake, termed diet-induced thermogenesis, are also attributed to BAT. These properties render BAT a potential target to combat diet-induced obesity. However, studies investigating the role of UCP1 to protect against diet-induced obesity are controversial and rely on the phenotyping of a single constitutive UCP1-knockout model. To address this issue, we generated a novel UCP1-knockout model by Cre-mediated deletion of Exon 2 in the UCP1 gene. We studied the effect of constitutive UCP1 knockout on metabolism and the development of diet-induced obesity. Methods UCP1 knockout and wildtype mice were housed at 30°C and fed a control diet for 4-weeks followed by 8-weeks of high-fat diet. Body weight and food intake were monitored continuously over the course of the study and indirect calorimetry was used to determine energy expenditure during both feeding periods. Results Based on Western blot analysis, thermal imaging and noradrenaline test, we confirmed the lack of functional UCP1 in knockout mice. However, body weight gain, food intake and energy expenditure were not affected by deletion of UCP1 gene function during both feeding periods. Conclusion Conclusively, we show that UCP1 does not protect against diet-induced obesity at thermoneutrality. Further we introduce a novel UCP1-KO mouse enabling the generation of conditional UCP1-knockout mice to scrutinize the contribution of UCP1 to energy metabolism in different cell types or life stages.

scholarly journals Murine neuronatin deficiency is associated with a hypervariable food intake and bimodal obesity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irene Cimino ◽  
Debra Rimmington ◽  
Y. C. Loraine Tung ◽  
Katherine Lawler ◽  
Pierre Larraufie ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Expenditure ◽  
Positive Energy ◽  
Chow Diet ◽  
Chromatin Regulator ◽  
Positive Energy Balance ◽  
The Impact ◽  
Deficient Mice

AbstractNeuronatin (Nnat) has previously been reported to be part of a network of imprinted genes downstream of the chromatin regulator Trim28. Disruption of Trim28 or of members of this network, including neuronatin, results in an unusual phenotype of a bimodal body weight. To better characterise this variability, we examined the key contributors to energy balance in Nnat+/−p mice that carry a paternal null allele and do not express Nnat. Consistent with our previous studies, Nnat deficient mice on chow diet displayed a bimodal body weight phenotype with more than 30% of Nnat+/−p mice developing obesity. In response to both a 45% high fat diet and exposure to thermoneutrality (30 °C) Nnat deficient mice maintained the hypervariable body weight phenotype. Within a calorimetry system, food intake in Nnat+/−p mice was hypervariable, with some mice consuming more than twice the intake seen in wild type littermates. A hyperphagic response was also seen in Nnat+/−p mice in a second, non-home cage environment. An expected correlation between body weight and energy expenditure was seen, but corrections for the effects of positive energy balance and body weight greatly diminished the effect of neuronatin deficiency on energy expenditure. Male and female Nnat+/−p mice displayed subtle distinctions in the degree of variance body weight phenotype and food intake and further sexual dimorphism was reflected in different patterns of hypothalamic gene expression in Nnat+/−p mice. Loss of the imprinted gene Nnat is associated with a highly variable food intake, with the impact of this phenotype varying between genetically identical individuals.

Effects of meal frequency on energy utilization in rats

1988 ◽  
Vol 255 (4) ◽  
pp. R616-R621 ◽  
Author(s):  
J. O. Hill ◽  
J. C. Anderson ◽  
D. Lin ◽  
F. Yakubu
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Body Weight Gain ◽  
Energy Utilization ◽  
Male Rats ◽  
Major Influence ◽  
Meal Frequency ◽  
Ad Libitum

The effects of differences in meal frequency on body weight, body composition, and energy expenditure were studied in mildly food-restricted male rats. Two groups were fed approximately 80% of usual food intake (as periodically determined in a group of ad libitum fed controls) for 131 days. One group received all of its food in 2 meals/day and the other received all of its food in 10-12 meals/day. The two groups did not differ in food intake, body weight, body composition, food efficiency (carcass energy gain per amount of food eaten), or energy expenditure at any time during the study. Both food-restricted groups had a lower food intake, body weight gain, and energy expenditure than a group of ad libitum-fed controls. In conclusion, these results suggest that amount of food eaten, but not the pattern with which it is ingested, has a major influence on energy balance during mild food restriction.

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