Responses of rufous hummingbirds to midday fasts

1985 ◽  
Vol 63 (10) ◽  
pp. 2249-2253 ◽  
Author(s):  
Zena J. Tooze ◽  
Clifton Lee Gass
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Intake ◽  
Laboratory Tests ◽  
Net Energy ◽  
Energy Reserves ◽  
Metabolic Costs ◽  
Net Energy Intake ◽  
Highly Correlated

This study investigates how rufous hummingbirds regain energy balance after experimentally imposed midday fasts reduce their energy reserves. Net energy balance calculated from food intake, activity budgets, and allometric equations for the costs of flying and perching was highly correlated with change in body weight in laboratory tests of 3 h or more. Individuals accumulated energy and body weight at the same rate after fasts as before, resulting in energy deficits at the end of the day compared with control conditions. Energy balance relative to control values was regained by the following morning, primarily by reducing metabolic costs in the dark through torpor. Net energy intake increased the following day, but this increase was relatively unimportant to reestablishing equilibrium.

Quantification of changes in body weight and body condition scores during lactation by modelling individual energy balance and total net energy intake

2001 ◽  
Vol 72 (2) ◽  
pp. 325-334 ◽  
Author(s):  
R. Schwager-Suter ◽  
C. Stricker ◽  
D. Erdin ◽  
N. Künzi
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Energy Intake ◽  
Body Condition ◽  
Dairy Cow ◽  
Fixed Effects ◽  
Net Energy ◽  
Net Energy Intake ◽  
Gut Fill ◽  
Body Condition Scores

AbstractIndividual energy balances (EB) and total net energy intake (NEI) were modelled to quantify the energy content of the explanatory variables body-weight change corrected for gut fill (BWC) and body condition-score change (BCSC). A total of 6147 records from 213 lactating dairy cows, 71 Holstein-Friesians, 71 Jerseys and 71 HolsteinJersey F1-crosses was analysed (1st, 2nd and >2nd lactation). Data were collected during 210 days of lactation, from calving to week 30. Individual EB were calculated as total energy for lactation (MJ NEL) minus estimated energy necessary for maintenance and production. Body-weight changes were calculated as differences between weekly means of body weight corrected for gut fill (BWCw) as well as from polynomial regression (BWCp). BCSC were differences between assessed body condition scores. The study included analyses of 1- and of 4-week periods for BWCw and BWCp, of differences between measuring periods for BCSC as well as separate analyses of data from cows in either negative or positive energy balance.Analysis of repeated measurements were performed applying mixed model theory. Models for EB contained type of dairy cow, lactation and type of roughage as fixed effects, week of lactation and either BWCw, BWCp or BCSC. Models for NEI contained type of dairy cow, lactation and quality of roughage as fixed effects, week of lactation as well as energy corrected milk, metabolic body weight and either BWCw, BWCp or BCSC as covariates.Most plausible energy contents per unit body tissue change were estimated for BWCp from weekly data with either EB (with energy partitioned into milk production and maintenance fixed) or NEI (no restrictions concerning partitioning) as the response variable. The estimated energy contents for BWCp were 15·40 and 10·47 MJ NEL, respectively.

scholarly journals Effects of extreme environments on food intake in human subjects

1999 ◽  
Vol 58 (4) ◽  
pp. 791-798 ◽  
Author(s):  
Margriet S. Westerterp-Plantenga
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Intake ◽  
Food Availability ◽  
Human Subjects ◽  
Acute Mountain Sickness ◽  
Extreme Environments ◽  
Adequate Food ◽  
Geographical Regions

Effects of extreme environments on food intake in human subjects are analysed as behavioural and physiological adaptations to annual and circadian rhythms, temperature and altitude. Effects of the environment on food intake through food availability have direct consequences on energy balance and body weight. Different geographical regions show variations in the composition of dietary foods, i.e. the relative proportions of carbohydrate, protein and fat. In developing countries the annual cycle appears to affect body weight through dependence on food availability. In West-European countries this effect appears to depend on physical activity. Energy and macronutrient intakes appear to follow a circadian pattern, with breakfast being relatively high in carbohydrate and dinner being relatively high in fat. In cold conditions, maintaining an adequate food intake is important in sustaining normal physiological responses to cold. Evidence for a possible cold-induced increase in appetite is poor. A condition influencing level of intake is the palatability of the food. High altitude, i.e. hypobaric hypoxia, appears to reduce appetite, energy intake and body mass, irrespective of acute mountain sickness (AMS). Meal size is reduced and meal frequency increased. Under circumstances of AMS, dissociation between appetite and hunger occurs. Thus, spontaneous adaptation to extreme environments requiring increased energy intake occurs first by adaptation of body weight to a new energy balance. In general, prevention of a negative energy balance occurs by learning with respect to food intake. After return to normal, adjustment of energy intake to the original energy balance occurs with restoration of body weight.

The long-acting amylin/calcitonin receptor agonist ZP5461 suppresses food intake and body weight in male rats

2021 ◽  
Author(s):  
Lauren M. Stein ◽  
Lauren E McGrath ◽  
Rinzin Lhamo ◽  
Kieran Koch-Laskowski ◽  
Samantha M. Fortin ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Intake ◽  
Receptor Agonist ◽  
Body Weight Gain ◽  
Male Rats ◽  
Calcitonin Receptor ◽  
Long Acting

The peptide hormone amylin reduces food intake and body weight, and is an attractive candidate target for novel pharmacotherapies to treat obesity. However, the short half-life of native amylin and amylin analogs like pramlintide limits these compounds' potential utility in promoting sustained negative energy balance. Here, we evaluate the ability of the novel long-acting amylin/calcitonin receptor agonist ZP5461 to reduce feeding and body weight in rats, and also test the role of calcitonin receptors (CTRs) in the dorsal vagal complex (DVC) of the hindbrain in the energy balance effects of chronic ZP5461 administration. Acute dose-response studies indicate that systemic ZP5461 (0.5-3 nmol/kg) robustly suppresses energy intake and body weight gain in chow- and high-fat diet (HFD)-fed rats. When HFD-fed rats received chronic systemic administration of ZP5461 (1-2 nmol/kg), the compound initially produced reductions in energy intake and weight gain, but failed to produce sustained suppression of intake and body weight. Using virally-mediated knockdown of DVC CTRs, the ability of chronic systemic ZP5461 to promote early reductions in intake and body weight gain was determined to be mediated in part by activation of DVC CTRs, implicating the DVC as a central site of action for ZP5461. Future studies should address other dosing regimens of ZP5461 to determine whether an alternative dose/frequency of administration would produce more sustained body weight suppression.

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%.

Secretin as a satiation whisperer with the potential to turn into an obesity-curbing knight

Endocrinology ◽  
2021 ◽  
Author(s):  
Katharina Schnabl ◽  
Yongguo Li ◽  
Mueez U-Din ◽  
Martin Klingenspor
Keyword(s):  
Bariatric Surgery ◽  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Weight Control ◽  
Therapeutic Potential ◽  
Physiological Mechanism ◽  
Gut Hormones ◽  
Metabolic Effects ◽  
Beneficial Effects

Abstract The obesity pandemic requires effective preventative and therapeutic intervention strategies. Successful and sustained obesity treatment is currently limited to bariatric surgery. Modulating the release of gut hormones is considered promising to mimic bariatric surgery with its beneficial effects on food intake, body weight and blood glucose levels. The gut peptide secretin was the first molecule to be termed a hormone; nevertheless, it only recently has been established as a legitimate anorexigenic peptide. In contrast to gut hormones that crosstalk with the brain either directly or by afferent neuronal projections, secretin mediates meal-associated brown fat thermogenesis to induce meal termination, thereby qualifying this physiological mechanism as an attractive, peripheral target for the treatment of obesity. In this perspective, it is of pivotal interest to deepen our yet superficial knowledge on the physiological roles of secretin as well as meal-associated thermogenesis in energy balance and body weight regulation. Of note, the emerging differences between meal-associated thermogenesis and cold-induced thermogenesis must be taken into account. In fact, there is no correlation between these two entities. In addition, the investigation of potential effects of secretin in hedonic-driven food intake, bariatric surgery as well as chronic treatment using suitable application strategies to overcome pharmacokinetic limitations will provide further insight into its potential to influence energy balance. The aim of this article is to review the facts on secretin’s metabolic effects, address prevailing gaps in our knowledge, and provide an overview on the opportunities and challenges of the therapeutic potential of secretin in body weight control.

EFFECTS OF CORRECTING FOR FEEDING LEVELS ON ESTIMATES OF GENETIC PARAMETERS OF MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Protein Yield ◽  
Net Energy ◽  
Yield Traits ◽  
Genetic And Phenotypic Correlations ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.

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.

Abstract P022: Determinants of Energy Balance: Differences Related to Body Weight and Body Composition

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Gregory A Hand ◽  
Robin P Shook ◽  
Jason R Jaggers ◽  
Amanda Paluch ◽  
Vivek K Prasad ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Positive Association ◽  
Linear Modeling ◽  
Obesity Epidemic ◽  
And Storage ◽  
Lean Group

Conversion, utilization and storage of energy in the regulation of energy balance is poorly understood. These misconceptions arise from confusion related to energy balance and its impact on body weight and composition, and can bias the interpretation of findings that are important for the development of policies addressing the obesity epidemic. PURPOSE: Our purpose was to examine the regulation of interactions between total daily energy intake (TDEI) and energy expenditure (TDEE) in healthy adults. METHODS: Adults not limited by gender, race or ethnicity (n=430; aged 21 to 40; BMI of 20 to 35) participated in a battery of physiological, anthropomorphic, behavioral and psychological measurements that are associated with energy balance regulation. The primary components of energy balance regulation (TDEI and TDEE) were measured by 3 random 24-hour dietary recalls and SenseWear accelerometry, respectively. Body composition was determined by dual x-ray absorptiometry (DXA). Absolute and relative resting metabolic rates (aRMR and rRMR) were determined through hooded indirect calorimetry. General linear modeling was used to examine the relationships of weight and body fatness with TDEI and macronutrient composition as well as the largest components of TDEE including aRMR, rRMR and physical activity energy expenditure (PAEE). In addition, data were compared between participants with a healthy body fat % (below 25; n=123) and obese (at or above 30%; n=241). RESULTS: All results were adjusted for age, gender and race. TDEE was positively associated (r=.47, p<.001) with TDEI. There was a positive association between aRMR (L/min) and weight (r=.743, p<.001). By contrast, rRMR (ml/kg/min) was inversely correlated with body weight (r= -.38; p<.001). TDEI was significantly higher in the lean group (2465±66 to 1878±42, p<.001) with no measureable differences in macronutrient percentages. The lean group had a higher TDEE and PAEE as compared to the obese group. CONCLUSIONS: There was a robust matching of TDEI and TDEE across weight and body composition ranges. Heavy people burned more calories than lighter people although the lighter individuals had a higher rRMR. The leaner group had a higher TDEI, reflecting a potential regulation based on the greater TDEE in this group. Further, the increased TDEE could be explained by the higher PAEE (approximately 500 kcal) in leaner individuals. These findings emphasize that energy expenditure is related to mass rather than body composition. The regulation of energy intake and body composition is multifactorial, with PAEE a significant determinant for energy storage. This study was funded through an unrestricted grant from The Coca-Cola Company.

scholarly journals Effects of Consuming Sugar-Sweetened Beverages for 2 Weeks on 24-h Circulating Leptin Profiles, Ad Libitum Food Intake and Body Weight in Young Adults

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3893 ◽  
Author(s):  
Desiree M. Sigala ◽  
Adrianne M. Widaman ◽  
Bettina Hieronimus ◽  
Marinelle V. Nunez ◽  
Vivien Lee ◽  
...  
Keyword(s):  
Young Adults ◽  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Energy Intake ◽  
Body Weight Gain ◽  
Energy Requirement ◽  
Area Under The Curve ◽  
Sugar Sweetened Beverage ◽  
Ad Libitum

Sugar-sweetened beverage (sugar-SB) consumption is associated with body weight gain. We investigated whether the changes of (Δ) circulating leptin contribute to weight gain and ad libitum food intake in young adults consuming sugar-SB for two weeks. In a parallel, double-blinded, intervention study, participants (n = 131; BMI 18–35 kg/m2; 18–40 years) consumed three beverages/day containing aspartame or 25% energy requirement as glucose, fructose, high fructose corn syrup (HFCS) or sucrose (n = 23–28/group). Body weight, ad libitum food intake and 24-h leptin area under the curve (AUC) were assessed at Week 0 and at the end of Week 2. The Δbody weight was not different among groups (p = 0.092), but the increases in subjects consuming HFCS- (p = 0.0008) and glucose-SB (p = 0.018) were significant compared with Week 0. Subjects consuming sucrose- (+14%, p < 0.0015), fructose- (+9%, p = 0.015) and HFCS-SB (+8%, p = 0.017) increased energy intake during the ad libitum food intake trial compared with subjects consuming aspartame-SB (−4%, p = 0.0037, effect of SB). Fructose-SB decreased (−14 ng/mL × 24 h, p = 0.0006) and sucrose-SB increased (+25 ng/mL × 24 h, p = 0.025 vs. Week 0; p = 0.0008 vs. fructose-SB) 24-h leptin AUC. The Δad libitum food intake and Δbody weight were not influenced by circulating leptin in young adults consuming sugar-SB for 2 weeks. Studies are needed to determine the mechanisms mediating increased energy intake in subjects consuming sugar-SB.

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