Energy metabolism of Inuit sled dogs

ObjectiveBulimia nervosa (BN) and binge eating disorder (BED) are eating disorders (EDs) characterized by recurrent binge eating (BE) episodes. Overlap exists between ED diagnostic groups, with BE episodes presenting one clinical feature that occurs transdiagnostically. Neuroimaging of the responses of those with BN and BED to disorder-specific stimuli, such as food, is not extensively investigated. Furthermore, to our knowledge, there have been no previous published studies examining the neural response of individuals currently experiencing binge eating, to low energy foods. Our objective was to examine the neural responses to both low energy and high energy food images in three emotive categories (disgust; fear; and happy) in BN and BED participants.MethodsNineteen females with BN (n = 14) or BED (n = 5), comprising the binge eating group (BEG; N = 19), and 19 age-matched healthy control (HC)’s completed thorough clinical assessment prior to functional MRI (fMRI). Neural response to low energy and high energy foods and non-food images was compared between groups using whole-brain exploratory analyses, from which six regions of interest (ROI) were then selected: frontal, occipital, temporal, and parietal lobes; insula and cingulate.ResultsIn response to low energy food images, the BEG demonstrated differential neural responses to all three low energy foods categories (disgust; fear; and happy) compared to HCs. Correlational analyses found a significant association between frequency of binge episodes and diminished temporal lobe and greater occipital lobe response. In response to high energy food images, compared to HC’s, the BEG demonstrated significantly decreased neural activity in response to all high energy food images. The HC’s had significantly greater neural activity in the limbic system, occipital lobe, temporal lobe, frontal lobe, and limbic system in response to high energy food images.ConclusionResults in the low energy food condition indicate that binge frequency may be related to increased aberrant neural responding. Furthermore, differences were found between groups in all ROI’s except the insula. The neural response seen in the BEG to disgust food images may indicate disengagement with this particular stimuli. In the high energy food condition, results demonstrate that neural activity in BN and BED patients may decrease in response to high energy foods, suggesting disengagement with foods that may be more consistent with those consumed during a binge eating episode.

PII: S0022-3476(95)70387-X

BackgroundRecent investigations have identified that commercially available dietary supplements, containing a combination of thermogenic ingredients, can increase resting metabolic rate (RMR). Thermogenic dietary supplements can have a positive influence on RMR, but the magnitude can vary based on the active ingredient and/or combination of active ingredients. Additionally, further safety evaluation is needed on multi-ingredient supplements that contain caffeine, due to its potential effect on heart rate (HR) and blood pressure (BP). The purpose of this study was to examine the effects of a commercially available dietary supplement on RMR and hemodynamic variables in healthy females.Methods13 female participants (26.1 ± 11.3 years; 163.4 ± 9.1 cm; 63.7 ± 8.0 kg, and 24 ± 5 BMI) volunteered to participate in this investigation. Participants underwent two testing sessions separated by approximately 7 days. On their first visit, participants arrived to the laboratory after an overnight fast and underwent a baseline RMR, HR, and BP assessment. Next, each participant ingested a thermogenic dietary supplement or placebo and repeated the RMR, HR, and BP assessments at 60, 120, and 180-minutes post-ingestion. Approximately 1-week later, the alternative supplement was ingested and the assessments were repeated in the exact same manner. Data were analyzed via a 2-factor [2x4] within-subjects repeated measures analysis of variance (ANOVA). Post-hoc tests were analyzed via paired samples t-tests.ResultsRepeated measures ANOVA revealed a significant effect for time relative to raw RMR data. Post-hoc analysis revealed that the dietary supplement treatment significantly increased RMR at 60-minutes, 120-minutes, and 180-minutes post ingestion (p < 0.05) as compared to baseline RMR values. No changes in RMR were observed for the placebo treatment (p > 0.05). Heart rate was not significantly affected at any time point with either supplement; however, main effects of treatment and time were observed for both systolic and diastolic blood pressure (p < 0.05).ConclusionsThe thermogenic dietary supplement treatment experienced greater elevations in RMR as compared to baseline. Due to the slight elevations in blood pressure, caution should be taken for those with increased risk for hypertension or pre-hypertension. Taken on a daily basis, thermogenic dietary supplementation may increase overall energy expenditure, potentially leading to reductions in fat mass over time.

The aim of this study was to examine the associations between baseline and changes in resting metabolic rate (RMR) with chronic condition(s) and weight loss (WL). Sex stratified analysis was undertaken on 393 adults from the Wharton Weight Management Clinics. The association between baseline RMR and WL was examined adjusting for age, BMI, ethnicity and treatment time. The association between changes in RMR (ΔRMR) and WL was also examined adjusting for baseline RMR and above covariates. Models were further adjusted for high glucose, triglycerides, blood pressure, low-density lipoprotein (LDL) and low high-density lipoprotein (HDL). While men (6.0 ± 8.6 kg) and women (5.6 ± 8.3 kg) had significant WL throughout the intervention, their measured decreases in RMR (-48 ± 322 kcal and -5 ± 322 kcal, respectively) were non-significant (P > 0.05). Individuals with a high blood pressure had a higher baseline RMR and women with a high LDL had a lower baseline RMR than those without the chronic condition (P < 0.05). Regardless of sex, WL was not significantly associated with baseline RMR or ΔRMR (P > 0.05) in both models. Participants with a low baseline RMR do not appear to be at a disadvantage for WL. Further, WL can occur without decreases in RMR in populations with high levels of obesity and obesity-related comorbidities.

Malnutrition in children with cystic fibrosis: the energy-balance equation.

A wealth of cross-sectional studies found a link between sleep deprivation and food-related outcomes like energy intake and BMI. Recent experimental studies suggest that this link is causal. However, the mechanisms through which sleep deprivation influences intake remain unclear. Here, we tested two prevailing hypotheses: that sleep deprivation leads to 1) increased food reward sensitivity and 2) decreased food-related self-control.In a within-subject study (n = 60 normal-weight females), we compared outcome measures under normal sleep and partial sleep deprivation conditions. Our outcome measures were 1) proxies for food reward sensitivity – liking of high and low energy foods, 2) binary food choices ranging in level of self-control conflict, and 3) intake of high and low energy foods. Eye-movements during food choice were measured with an eye-tracker to gain insights in implicit food choice processes.Food reward sensitivity outcomes showed a lower liking of low energy foods after partial sleep deprivation. More high energy foods were chosen after partial sleep deprivation independent of the level of self-control conflict. Intake of high energy foods was higher in the partial sleep deprivation condition. Lastly, the number of gaze switches between high and low energy foods, an implicit measure of conflict in choice, was lower in the high-conflict trials after sleep deprivation than after a normal night sleep.To conclude, the increased intake of high energy foods after sleep deprivation may be driven by a decreased liking of low energy foods, rather than an increased liking of high energy foods. Further, sleep deprivation may affect self-control conflict detection as indicated by a lower number of gaze switches between food options.

To investigate the effect of meal size on postprandial metabolic response and excess post-exercise oxygen consumption(EPOC) in juvenile rock carp(Procypris rabaudi)[(13.05±0.17) g,n=44],experimental fish were lightly anaesthetized and force-fed with compound feed(meal sizes: 0%,0.5%,1% and 2% body weight) at(25 ±0.5)℃.After diet offered,oxygen consumption rates at different intervals were measured.Variables of postprandial metabolic and EPOC responses were calculated.The results of present study showed that resting metabolic rates(RMR) were not significantly different among all groups.The postprandial metabolic rate first increased and then slowly decreased to pre-fed level.The time to peak metabolic rate and the energy expended on Specific dynamic action(SDA) in 0.5% and 1% meal size groups were lower than that of 2% meal size group(P0.05).The peak metabolic rates(PMR) and the SDA coefficients were not significantly different among 0.5%,1% and 2% meal size groups.Pre-exercise metabolic rate in feeding group was significantly higher than that of fasting group(P0.05).Peak post-exercise metabolic rate,metabolic rate increment and excess post-exercise oxygen consumption magnitude were not significantly different between feeding group and fasting group.The maximum metabolic rate(MMR) and MMR/RMR were significantly higher than PMR and PMR/RMR(P0.05).The fish fulfilled the increased energy demand during digestive process by means of prolonged SDA duration with the increase of meal size.EPOC was not influenced by feeding in the fish.

The aim of the study was to determine, in a cohort of young children with intestinal failure (IF), whether the estimates of basal metabolic rate (BMR) by standard equations can approximate measured resting energy expenditure (REE) by indirect calorimetry (IC). IC was performed using the dilutional canopy technique. REE measurements were compared with standard, age-based estimation equations (World Health Organization) for BMR. Subjects were classified as hypermetabolic (REE > 110% BMR), hypometabolic (REE < 90% BMR), or normal (REE = 90%-110% BMR). Twenty-eight IF patients (11 girls, 17 boys) had an underlying diagnosis of necrotizing enterocolitis (n = 10) or a congenital gastrointestinal defect (n = 18). Median age was 5.3 months. Median interquartile range (IQR) REE was 46 (42-58) kcal · kg · day. Median (IQR) total energy intake provided 209% (172%-257%) of REE, with parenteral nutrition providing 76% (23%) of total energy intake. REE was variable, with 39% (n = 11) of measurements hypermetabolic, 39% (n = 11) hypometabolic, and the remaining 21% (n = 6) normal. Although REE was well correlated with estimated BMR (r = 0.82, P < 0.0001), estimated BMR was not consistently an adequate predictor of REE. BMR over- or underestimated REE by >10 kcal · kg · day in 15 of 28 (54%) patients. REE was not significantly correlated with severity of liver disease, nutritional status, total energy intake, or gestational age. Energy expenditure is variable among children with IF and IF-associated liver disease, with approximately 80% of our cohort exhibiting either hypo- or hypermetabolism. Standard estimation equations frequently do not correctly predict individual REE. Longitudinal studies of energy expenditure and body composition may be needed to guide provision of nutrition regimens.

Support of resting metabolic rate (RMR) by the beta-adrenergic receptors of the sympathetic nervous system is attenuated with age and contributes to declines in RMR. This may be mediated by an age-associated increase in oxidative stress that can suppress beta-adrenergic responsiveness and/or modulate sympathetic activity. To address these issues, RMR was determined in 12 young (23 +/- 1 yr, mean +/- SE) and 21 older (68 +/- 3 yr) adults before and during systemic infusion of ascorbic acid [bolus, 0.06 g/kg fat free mass (FFM); drip, 0.02]. Ascorbic acid increased plasma concentrations similarly in young (72 +/- 5 to 1107 +/- 114 micro mol/liter) and older (70 +/- 6 to 1022 +/- 63 micro mol/liter) adults, and reduced (P = 0.001) plasma concentrations of isoprostanes (young, -82.8 +/- 47; older, -107 +/- 29 pg/ml). Baseline RMR(FFM) was lower (5719 +/- 215 vs. 6703 +/- 328 kJ/d; P = 0.001) and muscle sympathetic nerve activity (MSNA) was greater (MSNA, 28 +/- 2 vs. 23 +/- 3 bursts/min; P < 0.05) in older compared with young. However, neither RMR(FFM) (young, +117 +/- 63; older, +163 +/- 48 kJ/d; P = 0.14) or MSNA (young, 0 +/- 2; older, -1 +/- 1 bursts/min; P = 0.71) changed in either age group during ascorbic acid infusion compared with saline control. These results indicate that increased oxidative stress: 1) is not a mechanism contributing to decreases in RMR with primary aging; and 2) does not modulate MSNA in healthy adult humans.

A Comparison of Measured Resting Energy Expenditure (REE) with Predicted Resting Energy Expenditure (REE) in Morbidly Obese Patients

An acute eccentric exercise bout produces muscle damage and delayed onset muscle soreness (DOMS). Both are attenuated following a subsequent eccentric exercise bout indicating that an adaptation occurs. The degree to which this type of exercise influences recovery energy expenditure is unknown. PURPOSE: We investigated whether excess postexercise oxygen consumption (EPOC) measured for 2h and resting metabolic rate (RMR) measured 24h (day 2) and 48h (day 3) post-exercise would differ following level vs downhill treadmill running. METHODS: Eight untrained male subjects performed three 40min submaximal exercise trials eliciting ∼70% VO2max: a level running trial and two downhill running trials (DH1 and DH2). DH1 was performed 1wk after level, and DH2 2wk after DH1. Testing occurred in the morning following an overnight fast and no strenuous exercise for the previous 36h. Baseline RMR was measured for 30min pre-exercise. DOMS was rated for five lower body sites at 24h and 48h post exercise. Analyses included 1- and 2-way ANOVA and Friedman tests. RESULTS: When compared to baseline, VO2 was significantly elevated at 60 (p < .01) and 90min (p < .03) for DH1 and at 60min (p < .03) for DH2, whereas VO2 was not significantly elevated at any of these time points during the level trial. However, there was no significant difference in the accumulated 2h EPOC among trials (level = 7.04/5.32, DH1 = 8.55í4.12, and DH2 = 8.38í2.89 L). RMR was not significantly different among days or among trials. DH1 produced significantly greater DOMS than level running (p < .01) at all 5 sites. CONCLUSION: It can be concluded that the first bout of downhill running for 40min at a moderately high intensity, which produced a significant amount of DOMS, resulted in a prolonged EPOC (> 90min). However, an elevated metabolic rate was not detected 24 or 48th following exercise when DOMS was evident. In contrast, metabolic rate returned to the resting value within 1h after running on a level grade. The physiological mechanisms involved in producing a prolonged elevation in metabolic rate following downhill running remain to be elucidated.

Metabolic consequences of body size and body composition in hemodialysis patients

Seasonal variation in thermal energetics of the Australian owlet-nightjar ( Aegotheles cristatus)

The reliability of resting energy expenditure (REE) measurements by indirect calorimetry with a ventilated hood was investigated in 50 healthy controls and 10 patients with liver cirrhosis. In each subject basal energy expenditure (BEE) was determined once and REE three times (morning REE1, noon REE2, afternoon REE3). In controls and patients the first 5-minute BEE and first 5-minute REE (controls also second 5-minute REE) were higher than in the remainder of the 30-minute recording. Only the last 20 minutes of recordings were used to calculate BEE (1645 +/- 315, mean +/- SD, in kilocalories per day), REE1 (1880 +/- 365), REE2 (1782 +/- 384), and REE3 (1775 +/- 316) in controls, and in cirrhotics: BEE (1530 +/- 235), REE1 (1714 +/- 267), REE2 (1715 +/- 238), and REE3 (1779 +/- 275). REE was higher than BEE in controls and cirrhotics (p less than 0.05). The REE variation coefficient was 5 +/- 3% in controls and 5 +/- 2% in cirrhotics. No systematic difference between REE1, REE2, and REE3 was found. Energy expenditure predicted by the Harris-Benedict equation differed up to 21% from measured BEE in individual controls; group mean BEE, however, was correctly predicted. In cirrhotics differences between measured and predicted BEE up to 26% occurred, while measured BEE was higher than predicted BEE (p = 0.06). It is concluded that REE can be reliably assessed by indirect calorimetry with a ventilated hood system in controls and patients at any time of the day, when values obtained in the first 10 minutes are deleted.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy management models provide theories and predictions for how animals manage their energy budgets within their energetic constraints, in terms of their resting metabolic rate (RMR) and daily energy expenditure (DEE). Thus, uncovering what associations exist between DEE and RMR is key to testing these models. Accordingly, there is considerable interest in the relationship between DEE and RMR at both inter- and intraspecific levels. Interpretation of the evidence for particular energy management models is enhanced by also considering the energy spent specifically on costly activities (activity energy expenditure [AEE] = DEE - RMR). However, to date there have been few intraspecific studies investigating such patterns. Our aim was to determine whether there is a generality of intraspecific relationships among RMR, DEE, and AEE using long-term data sets for bird and mammal species. For mammals, we use minimum heart rate (fH), mean fH, and activity fH as qualitative proxies for RMR, DEE, and AEE, respectively. For the birds, we take advantage of calibration equations to convert fH into rate of oxygen consumption in order to provide quantitative proxies for RMR, DEE, and AEE. For all 11 species, the DEE proxy was significantly positively correlated with the RMR proxy. There was also evidence of a significant positive correlation between AEE and RMR in all four mammal species but only in some of the bird species. Our results indicate there is no universal rule for birds and mammals governing the relationships among RMR, AEE, and DEE. Furthermore, they suggest that birds tend to have a different strategy for managing their energy budgets from those of mammals and that there are also differences in strategy between bird species. Future work in laboratory settings or highly controlled field settings can tease out the environmental and physiological processes contributing to variation in energy management strategies exhibited by different species.