Measurement Of Energy Expenditure Research Articles

A pilot randomised controlled trial of ride-on cars and postural combinations of standing and sitting for mobility and social function in toddlers with motor delays

Purpose Locomotor experiences in upright postures are essential for developing toddlers’ mobility and social functions. This pilot randomised controlled trial aimed to examine the effectiveness of using a modified ride-on car (ROC) with postural combinations of standing and sitting on mobility and social function in toddlers with motor delays. Materials and methods Nineteen participants aged 1–3 years with mild, moderate or severe motor delays were randomly assigned to four ROC groups. The ROC groups had different combinations of standing and sitting, namely standing for 70 min (ROC-Stand70, five participants), standing for 45 min (ROC-Stand45, four participants), standing for 25 min (ROC-Stand25, five participants) and sitting for 70 min (ROC-Sit70, five participants). All participants participated in 2-h sessions twice a week for 12 weeks. The Pediatric Evaluation of Disability Inventory, Goal Attainment Scaling and Bayley-III tests were administered before and after the intervention, and after 12 weeks of follow-up. A mixed-model analysis of variance was used to compare inter- and intra-group differences. This trial was registered at ClinicalTrials.gov (NCT03707405). Results All groups showed significantly improved mobility, social function and goal achievement at the post-test (p < .001). However, no significant changes were observed in Bayley scores. Conclusions Combining physical and social environmental modifications with active exploration is crucial for early power mobility training in toddlers with motor delays. To enhance the robustness and generalisability of our findings, future studies should include larger sample sizes, consider variations in motor delays, and measure energy expenditure during the intervention. Implications for rehabilitation Providing active exploratory experience using ride-on cars (ROCs) with various postural combinations can improve a child’s mobility. The ROC training with various postural combinations can improve social function, and the degree of improvement may depend on the severity of motor delays. Setting goals with caregivers and incorporating their roles in the training process can empower them to interact with children more frequently and actively.

Comparison of energy expenditure measurements by a new basic respiratory room vs. classical ventilated hood

BackgroundNutritional support is often based on predicted resting energy expenditure (REE). In patients, predictions seem invalid. Indirect calorimetry is the gold standard for measuring EE. For assessments over longer periods (up to days), room calorimeters are used. Their design makes their use cumbersome, and warrants improvements to increase utility. Current study aims to compare data on momentary EE, obtained by a basic respiration room vs. classical ventilated hood. The objective is to compare results of the basic room and to determine its 1)reliability for measuring EE and 2)sensitivity for minute changes in activity.MethodsTwo protocols (P1; P2)(n = 62; 25 men/37 women) were applied. When measured by hood, participants in both protocols were in complete rest (supine position). When assessed by room, participants in P1 were instructed to stay half-seated while performing light desk work; in P2 participants were in complete rest mimicking hood conditions. The Omnical calorimeter operated both modalities. Following data were collected/calculated: Oxygen uptake (V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} O2(ml/min)), carbon dioxide production (V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} CO2ml/min), 24h_EE (kcal/min), and respiratory exchange ratio (RER). Statistical analyses were done between modalities and between protocols. The agreement between 24h_EE, V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} O2 and V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} CO2 obtained by both modalities was investigated by linear regression. Reliability analysis on 24h_EE determined ICC.ResultsNo significant differences were found for 24h_EE and V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} O2. V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} CO2 significantly differed in P1 + P2, and P2 (hood > room). RER was significantly different (hood > room) for P1 + P2 and both protocols individually. Reliability of 24h_EE between modalities was high. Modality-specific results were not different between protocols.Discussion/conclusionThe room is valid for assessing momentary EE. Minute changes in activity lead to a non-significant increase in EE and significant increase in RER. The significant difference in V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\\mathrm{V}}$$\\end{document} CO2 for hood might be related to perceived comfort. More research is necessary on determinants of RER, type (intensity) of activity, and restlessness. The design of the room facilitates metabolic measurements in research, with promising results for future clinical use.

The impact of 60days of -6° head down tilt bed rest on mitochondrial content, respiration and regulators of mitochondrial dynamics.

It is unclear how skeletal muscle metabolism and mitochondrial function adapt to long duration bed rest and whether changes can be prevented by nutritional intervention. The present study aimed (1) to assess the effect of prolonged bed rest on skeletal muscle mitochondrial function and dynamics and (2) to determine whether micronutrient supplementation would mitigate the adverse metabolic effect of bed rest. Participants were maintained in energy balance throughout 60days of bed rest with micronutrient supplementation (INT) (body mass index: 23.747±1.877kgm-2 ; 34.80±7.451years; n=10) or without (control) (body mass index: 24.087±2.088kgm-2 ; 33.50±8.541years; n=10). Indirect calorimetry and dual-energy x-ray absorptiometry were used for measures of energy expenditure, exercise capacity and body composition. Mitochondrial respiration was determined by high-resolution respirometry in permeabilized muscle fibre bundles from vastus lateralis biopsies. Protein and mRNA analysis further examined the metabolic changes relating to regulators of mitochondrial dynamics induced by bed rest. INT was not sufficient in preserving whole body metabolic changes conducive of a decrease in body mass, fat-free mass and exercise capacity within both groups. Mitochondrial respiration, OPA1 and Drp1 protein expression decreased with bed rest, with an increase pDrp1s616 . This reduction in mitochondrial respiration was explained through an observed decrease in mitochondrial content (mtDNA:nDNA). Changes in regulators of mitochondrial dynamics indicate an increase in mitochondrial fission driven by a decrease in inner mitochondrial membrane fusion (OPA1) and increased pDrp1s616 . KEY POINTS: Sixty days of -6° head down tilt bed rest leads to significant changes in body composition, exercise capacity and whole-body substrate metabolism. Micronutrient supplementation throughout bed rest did not preserve whole body metabolic changes. Bed rest results in a decrease in skeletal muscle mitochondrial respiratory capacity, mainly as a result of an observed decrease in mitochondrial content. Prolonged bed rest ensues changes in key regulators of mitochondrial dynamics. OPA1 and Drp1 are significantly reduced, with an increase in pDrp1s616 following bed rest indicative of an increase in mitochondrial fission. Given the reduction in mitochondrial content following 60days of bed rest, the maintenance of regulators of mitophagy in line with the increase in regulators of mitochondrial fission may act to maintain mitochondrial respiration to meet energy demands.

Forecasting individual exercise sweat losses from forecast air temperature and energy expenditure.

Recent success in predicting individual sweat losses from air temperature and energy expenditure measurements suggests a potential for forecasting individual sweat losses for future combinations of environment and exercise. The purpose of this study is to determine the plausibility of accurately forecasting exercise sweat losses from meteorological air temperature forecasts and individual running energy expenditure forecasts. The potential impact on plasma sodium is also estimated when setting drinking rates equal to forecast sweat losses. Individual exercise sweat losses (equated to water needs) and energy expended while running were measured in 33 participants along with air temperature and compared with forecasts of the same. Forecast inputs were used in a web app to forecast exercise sweat losses for comparison with observed values. The bias between forecast and observed exercise sweat losses was used to calculate the potential drinking impact on plasma sodium. The concordance correlation coefficient between forecast and observed values was 0.95, 0.96, and 0.91 for air temperature, energy expenditure, and exercise sweat losses, respectively, indicating excellent agreement and no significant differences observed via t-test. Perfect matching of water intake to sweat losses would lower plasma sodium concentrations from 140 to 138 mmol/L; calculations using the 95% limits of agreement for bias showed that drinking according to forecast exercise sweat losses would alter plasma sodium concentrations from 140 to between 136 and 141 mmol/L. The outcomes support the strong potential for accurately forecasting exercise sweat losses from commonly available meteorological air temperature forecasts and energy expenditure from forecast running distance.

Determining energy expenditure in a large seabird using accelerometry.

The trade off between energy gained and expended is the foundation of understanding how, why and when animals perform any activity. Based on the concept that animal movements have an energetic cost, accelerometry is increasingly being used to estimate energy expenditure. However, validation of accelerometry as an accurate proxy for field metabolic rate in free-ranging species is limited. In the present study, Australasian gannets (Morus serrator) from the Pope's Eye colony (38°16'42″S 144°41'48″E), south-eastern Australia, were equipped with GPS and tri-axial accelerometers and dosed with doubly labelled water (DLW) to measure energy expenditure during normal behaviour for 3-5 days. The correlation between daily energy expenditure from the DLW and vectorial dynamic body acceleration (VeDBA) was high for both a simple correlation and activity-specific approaches (R2=0.75 and 0.80, respectively). Varying degrees of success were observed for estimating at-sea metabolic rate from accelerometry when removing time on land using published energy expenditure constants (R2=0.02) or activity-specific approaches (R2=0.42). The predictive capacity of energy expenditure models for total and at-sea periods was improved by the addition of total distance travelled and proportion of the sampling period spent at sea during the night, respectively (R2=0.61-0.82). These results indicate that accelerometry can be used to estimate daily energy expenditure in free-ranging gannets and its accuracy may depend on the inclusion of movement parameters not detected by accelerometry.

High-fat diet feeding disrupts the coupling of thermoregulation to energy homeostasis

ObjectivePreserving core body temperature across a wide range of ambient temperatures requires adaptive changes of thermogenesis that must be offset by corresponding changes of energy intake if body fat stores are also to be preserved. Among neurons implicated in the integration of thermoregulation with energy homeostasis are those that express both neuropeptide Y (NPY) and agouti-related protein (AgRP) (referred to herein as AgRP neurons). Specifically, cold-induced activation of AgRP neurons was recently shown to be required for cold exposure to increase food intake in mice. Here, we investigated how consuming a high-fat diet (HFD) impacts various adaptive responses to cold exposure as well as the responsiveness of AgRP neurons to cold. MethodsTo test this, we used immunohistochemistry, in vivo fiber photometry and indirect calorimetry for continuous measures of core temperature, energy expenditure, and energy intake in both chow- and HFD-fed mice housed at different ambient temperatures. ResultsWe show that while both core temperature and the thermogenic response to cold are maintained normally in HFD-fed mice, the increase of energy intake needed to preserve body fat stores is blunted, resulting in weight loss. Using both immunohistochemistry and in vivo fiber photometry, we show that although cold-induced AgRP neuron activation is detected regardless of diet, the number of cold-responsive neurons appears to be blunted in HFD-fed mice. ConclusionsWe conclude that HFD-feeding disrupts the integration of systems governing thermoregulation and energy homeostasis that protect body fat mass during cold exposure.

Total Energy Expenditure and Nutritional Intake in Continuous Multiday Ultramarathon Events.

Continuous multiday ultramarathon competitions are increasingly popular and impose extreme energetic and nutritional demands on competitors. However, few data have been published on energy expenditure during these events. Here, we report doubly labeled water-derived measures of total energy expenditure (in kilocalories per day) and estimated physical activity level (PAL: total energy expenditure/basal metabolic rate) collected from five elite and subelite finishers (four males and one female, age 34.6 ± 4.9years)-and nutritional intake data from the winner-of the Cocodona 250, a ∼402-km race in Arizona, and from a fastest-known-time record (one male, age 30years) on the ∼1,315-km Arizona Trail. PAL during these events exceeded four times basal metabolic rate (Cocodona range: 4.34-6.94; Arizona Trail: 5.63). Combining the results with other doubly labeled water-derived total energy expenditure data from ultraendurance events show a strong inverse relationship between event duration and PAL (r2 = .68, p < .0001). Cocodona race duration was inversely, though not significantly, associated with PAL (r2 = .70, p = .08). Water turnover varied widely between athletes and was not explained by PAL or body mass. The Cocodona race winner met ∼53% of energy demand via dietary intake, 85.6% of which was carbohydrate, while ∼47% of energy demand was met via catabolism of body energy stores. Together, these results illustrate the energetic deficits incurred during competitive continuous multiday ultramarathon efforts and implicate macronutrient absorption and/or storage as key factors in ultramarathon performance.

Validation of Metabolic Models for Estimation of Energy Expenditure During Isolated Concentric and Eccentric Muscle Contractions.

Musculoskeletal modeling uses metabolic models to estimate energy expenditure of human locomotion. However, accurate estimation of energy expenditure is challenging, which may be due to uncertainty about the true energy cost of eccentric and concentric muscle contractions. The purpose of this study was to validate three commonly used metabolic models, using isolated isokinetic concentric and eccentric knee extensions/flexions. Five resistance-trained adult males (25.6 ± 2.4 year, 90.6 ± 7.5 kg, 1.81 ± 0.09 m) performed 150 repetitions at four different torques in a dynamometer. Indirect calorimetry was used to measure energy expenditure during these muscle contractions. All three models underestimated the energy expenditure (compared with indirect calorimetry) for up to 55.8% and 78.5% for concentric and eccentric contractions, respectively. Further, the coefficient of determination was in general low for eccentric contractions (R2 < 0.46) indicating increases in the absolute error with increases in load. These results show that the metabolic models perform better when predicting energy expenditure of concentric contractions compared with eccentric contractions. Thus, more knowledge about the relationship between energy expenditure and eccentric work is needed to optimize the metabolic models for musculoskeletal modeling of human locomotion.

Validity of Actigraph for Measuring Energy Expenditure in Healthy Adults: A Systematic Review and Meta-Analysis.

The objective of this systematic review and meta-analysis was to assess the validity of the Actigraph triaxial accelerometer device in measuring physical activity energy expenditure (PAEE) in healthy adults, with indirect calorimetry (IC) serving as the validity criterion. A comprehensive search was conducted using the PubMed, Web of Science, and sportdiscuss databases, in addition to manual searches for supplementary sources. Search strategies were employed that involved conducting single keyword searches using the terms "gt3x" and "Actigraph gt3x". The literature search encompassed the timeframe spanning from 1 January 2010 to 1 March 2023. The methodological quality of the studies included in the analysis was evaluated using both the Downs and Black checklist and the Consensus-Based Criteria for Selection of Measurement Instruments (COSMIN) checklist. The meta-analysis was conducted using the Review Manager 5.4 software. The standardized mean difference (SMD) was calculated and expressed as a 95% confidence interval (CI). The significance level was set at α = 0.05. A systematic assessment of the Actigraph's performance was conducted through the descriptive analysis of computed effect sizes. A total of 4738 articles were retrieved from the initial search. After eliminating duplicate articles and excluding those deemed irrelevant, a comprehensive analysis was conducted on a total of 20 studies, encompassing a combined sample size of 1247 participants. The scores on the Downs and Black checklist ranged from 10 to 14, with a mean score of 11.35. The scores on the COSMIN checklist varied from 50% to 100%, with an average score of 65.83%. The meta-analysis findings revealed a small effect size (SMD = 0.01, 95% CI = 0.50-0.52, p = 0.97), indicating no statistically significant difference (p > 0.05). The meta-analysis revealed a small effect size when comparing the Actigraph and IC, suggesting that the Actigraph can be utilized for assessing total PAEE. Descriptive analyses have indicated that the Actigraph device has limited validity in accurately measuring energy expenditure during specific physical activities, such as high-intensity and low-intensity activities. Therefore, caution should be exercised when utilizing this device for such purposes. Furthermore, there was a significant correlation between the activity counts measured by the Actigraph and the PAEE, indicating that activity counts can be utilized as a predictive variable for PAEE.

The impact of prolonged fasting on 24h energy metabolism and its 24h rhythmicity in healthy, lean males: A randomized cross-over trial

Human energy expenditure and substrate oxidation are under circadian control and food intake is a time cue for the human biological clock, leading to 24h feeding-fasting cycles in energy and substrate metabolism. In recent years, (intermittent) fasting protocols have also become popular to improve metabolic health. Here, we aimed to investigate the impact of food intake on the 24h patterns of energy metabolism as well as to provide data on the timeline of changes in energy metabolism that occur upon an extended period of fasting. In a randomized, cross-over design, twelve healthy males underwent a 60h fast which was compared to a 60h fed condition. In the fed condition meals were provided at energy balance throughout the study. Conditions were separated by a two week period of habitual diet. Volunteers resided in a respiration chamber for the entire 60h to measure energy expenditure and substrate oxidation hour by hour. Volunteers performed a standardized activity protocol while in the chamber. Blood samples were drawn after 12, 36 and 60h. Immediately following the breakfast meal (in the fed condition), fat oxidation became higher in the fasted condition compared to the fed condition and remained elevated throughout the study period. The initial rapid increase in fat oxidation corresponded with a decline in the hepatokine activin A (r=-0.86, p=0.001). The contribution of fat oxidation to total energy expenditure gradually increased with extended abstinence from food, peaking after 51h of fasting at 160mg/min. Carbohydrate oxidation stabilized at a low level during the second day of fasting and averaged around 60mg/min with only modest elevations in response to physical activity. Although 24h energy expenditure was significantly lower with prolonged fasting (11.0±0.4 vs 9.8±0.2 and 10.9±0.3 vs 10.3±0.3MJ in fed vs fasting, day 2 and 3 respectively, p<0.01), the 24h fluctuations in energy expenditure were comparable between the fasted and fed condition. The fluctuations in substrate oxidation were, however, significantly (p<0.001 for both carbohydrate and fat oxidation) altered in the fasted state, favouring fat oxidation. Energy expenditure displays a day-night rhythm, which is independent of food intake. In contrast, the day-night rhythm of both carbohydrate and fat oxidation is mainly driven by food intake. Upon extended fasting, the absolute rate of fat oxidation rapidly increases and keeps increasing during a 60h fast, whereas carbohydrate oxidation becomes progressively diminished. www.trialregister.nl NTR 2042.

FRI025 Succinate Receptor Activation Increases Respiration In Human But Not Murine Brown Adipocytes

Abstract Disclosure: B.T. McNeill: None. A. Kelman: None. L.E. Ramage: None. K.J. Suchacki: None. S.J. Wakelin: None. N.M. Morton: None. R.H. Stimson: None. Brown adipose tissue (BAT) is a thermogenic tissue that generates heat to maintain body temperature. BAT activation is a potential therapeutic target for treating obesity-related cardiometabolic disease. We performed RNA sequencing of human primary brown and white adipocytes and identified SUCNR1, which encodes the succinate receptor, as highly differentially expressed (20-fold) in brown versus white adipocytes. Succinate is known to increase BAT thermogenesis, while SUCNR1 activation inhibits lipolysis in white adipose tissue (WAT). We hypothesized that SUCNR1 activation increases BAT thermogenesis in humans and in mice. To test this, we investigated the effect of succinate and the selective SUCNR1 agonist cis-epoxysuccinic acid (C-ESA) in human and murine primary brown/ beige adipocytes. In addition, we determined the metabolic effects of disruption of Sucnr1 in mice either fed control or a high fat (HFD) for 12 weeks and measured energy expenditure when housed at standard room temperature (21°C) and during cold exposure (4°C). In human brown and white adipocytes, succinate increased basal and noradrenaline-stimulated respiration, while C-ESA increased basal respiration only in human brown adipocytes without altering UCP1 mRNA levels. SUCNR1 activation reduced glycerol release only in human white adipocytes. Male (but not female) Sucnr1-/- mice exhibited impaired glucose tolerance versus Sucnr1+/+ littermates after 2 weeks of HFD, and greater fat mass was also observed in the Sucnr1-/- mice following chronic HFD. However, energy expenditure, locomotor activity and tail vein temperature were unchanged in male Sucnr1-/- mice either at 21°C or 4°C. In addition, expression of Ucp1 and Pgc1α in BAT and inguinal WAT were similar between genotypes. Sucnr1 deletion had no effect on fat mass or glucose tolerance in mice fed a control diet. In vitro, differentiated brown adipocytes from Sucnr1-/- mice demonstrated comparable cellular respiration and Ucp1 mRNA levels both basally and during noradrenaline stimulation to Sucnr1+/+ adipocytes. Succinate and C-ESA did not stimulate respiration in murine brown or white adipocytes. These data reveal that SUCNR1 activation enhances brown adipocyte respiration in human but not murine brown adipocytes, highlighting a novel pathway regulating BAT function in addition to differences between species. These data also reveal novel sex-specific differences in the metabolic effects of SUCNR1, although the mechanisms through which female mice are protected from the adverse metabolic effects of Sucnr1 deletion are unclear. SUCNR1 activation may be a novel therapeutic target to treat obesity and associated metabolic disease, but requires further research in humans to determine the specific mechanisms through which SUCNR1 regulates BAT thermogenesis. Presentation: Friday, June 16, 2023

Let Us Put More Energy Into Measuring Energy Expenditure: The Next Phase of Indirect Calorimetry.

Let Us Put More Energy Into Measuring Energy Expenditure: The Next Phase of Indirect Calorimetry.

Simulating Muscle-Level Energetic Cost Savings When Humans Run with a Passive Assistive Device.

Connecting the legs with a spring attached to the shoelaces, called an exotendon, can reduce the energetic cost of running, but how the exotendon reduces the energetic burden of individual muscles remains unknown. We generated muscle-driven simulations of seven individuals running with and without the exotendon to discern whether savings occurred during the stance phase or the swing phase, and to identify which muscles contributed to energy savings. We computed differences in muscle-level energy consumption, muscle activations, and changes in muscle-fiber velocity and force between running with and without the exotendon. The seven of nine participants who reduced energy cost when running with the exotendon reduced their measured energy expenditure rate by 0.9 W/kg (8.3%). Simulations predicted a 1.4 W/kg (12.0%) reduction in the average rate of energy expenditure and correctly identified that the exotendon reduced rates of energy expenditure for all seven individuals. Simulations showed most of the savings occurred during stance (1.5 W/kg), though the rate of energy expenditure was also reduced during swing (0.3 W/kg). The energetic savings were distributed across the quadriceps, hip flexor, hip abductor, hamstring, hip adductor, and hip extensor muscle groups, whereas no changes were observed in the plantarflexor or dorsiflexor muscles. Energetic savings were facilitated by reductions in the rate of mechanical work performed by muscles and their estimated rate of heat production. By modeling muscle-level energetics, this simulation framework accurately captured measured changes in whole-body energetics when using an assistive device. This is a useful first step towards using simulation to accelerate device design by predicting how humans will interact with assistive devices that have yet to be built.

Determining energy and protein needs in critically ill pediatric patients: A scoping review.

In critically ill pediatric patients, optimal energy and protein intakes are associated with a decreased risk of morbidity and mortality. However, the determination of energy and protein needs is complex. The objective of this scoping review was to understand the extent and type of evidence related to the methods used to determine energy and protein needs in critically ill pediatric patients. An international expert group composed of dietitians, pediatric intensivists, a nurse, and a methodologist conducted the review, based on the Johanna Briggs Institute methodology. Two researchers searched for studies published between 2008 and 2023 in two electronic databases, screened abstracts and relevant full texts for eligibility, and extracted data. A total of 39 studies were included, mostly conducted in critically ill children undergoing ventilation, to assess the accuracy of predictive equations for estimating resting energy expenditure (REE) (n = 16, 41%) and the impact of clinical factors (n = 22, 56%). They confirmed the risk of underestimation or overestimation of REE when using predictive equations, of which the Schofield equation was the least inaccurate. Apart from weight and age, which were positively correlated with REE, the impact of other factors was not always consistent. No new indirect calorimeter method used to determine protein needs has been validated. This scoping review highlights the need for scientific data on the methods used to measure energy expenditure and determine protein needs in critically ill children. Studies using a reference method are needed to validate an indirect calorimeter.

No evidence that the widespread environmental contaminant caffeine alters energy balance or stress responses in fish

AbstractAnthropogenic sources of environmental pollution are ever‐increasing as urban areas expand and more chemical compounds are used in daily life. The stimulant caffeine is one of the most consumed chemical compounds worldwide, and as a result, has been detected as an environmental contaminant in all types of major water sources on all continents. Exposure of wildlife to environmental pollutants can disrupt the energy balance of these organisms, as restoration of homeostasis is prioritised. In turn, energy allocated to other key biological processes such as growth or reproduction may be affected, consequently reducing the overall fitness of an individual. Therefore, we aimed to investigate if long‐term exposure to environmentally relevant concentrations of caffeine had any energetic consequences on wildlife. Specifically, we exposed wild eastern mosquitofish (Gambusia holbrooki) to one of three nominal concentrations of caffeine (0, 100 and 10,000 ng/L) and assayed individuals for metabolic rate, general activity, antipredator and foraging behaviour and body size as measures of energy expenditure or energy intake. We found no differences in any measured traits between any of the given exposure treatments, indicating that exposure to caffeine at current environmental levels may not adversely affect the energy balance and fitness of vulnerable freshwater fish.

Work resumption after invasive heart procedures, rehabilitation and ergonomic evaluation: from the hospital to the workplace.

Our Institute adopts a multidisciplinary protocol named "CardioWork" for work resumption after invasive cardiac procedures and subsequent rehabilitation: after evaluation of the cardiac functional profile, the occupational physician analyzes the work activity prior to the cardiopathological event, identifies the presumed task energy requirement (from specific, published tables), and compares it with the exercise test results. Indications regarding the timing and modality of returning to work are formulated accordingly. To verify the reliability of the indications thus provided, we carried out a clinical-functional follow-up study in the workplace with Holter electrocardiography (ECG) and armband measurement of actual energy expenditure. Over the course of 2 years, we enrolled 36 patients (mostly males, aged between 30 and 70 years) who were hospitalized after coronary revascularization, valve replacement, or cardiac defibrillator implant. After rehabilitation, instrumental diagnostics (Holter ECG, echocardiography, exercise test) showed discrete functional conditions, with better values with regard to cardiac function than exercise capacity and effort tolerance. All subjects were judged fit for the job, in most cases with limitations concerning ergonomic factors, working timetable, and/or stress. They returned to work quickly, with good adherence to the indications provided. The workplace Holter ECG did not show appreciable differences compared to the hospital evaluation. In one case, the average energy expenditure measured while working was higher than that inferred from the tables; in the remaining subjects, the actual expenditure coincided with what was expected or was lower. In a minority of cases (39%), the measured average expenditure slightly exceeded the optimal value (35% of the maximal value at the exercise test) recommended at the time of hospital discharge. At the end of the workplace evaluation, it was not necessary to formulate new indications. The study provides further evidence of the effectiveness of the CardioWork protocol in promoting a return to work after invasive heart procedures. Although they need continuous updating, the published estimates of presumed task energy requirements remain reliable. In particularly complex cases, however, it is advisable to carry out a field check of the ergometric assessments performed at the end of rehabilitation.

Exploring lighting conditions to reduce energy consumption and improve cognitive performance using immersive virtual environments

The global energy crisis has created an urgent demand to decrease the energy that buildings consume. In universities, the situation is complicated as campuses need to have a high level of comfort and, therefore, consume more energy than other building types. Lighting accounts for a high percentage of this energy expenditure and urgent measures are required to reduce this consumption and, thus, costs. A further complication is that lighting has been shown to have an important influence on cognitive learning processes. One such process is memory, which has a fundamental influence on modern society. In this study, we analyse the psychological responses of 143 students in a memory task in a virtual classroom using three illuminance levels (100 lx, 300 lx and 500 lx) and four colour temperatures (3000 K, 4000 K, 6500 K and 10500 K). The results showed that lighting conditions influence memory. The combination of 100 lx and 6500 K produced the best memory performance. The results showed that varying lighting parameters can significantly reduce the energy expenditure of educational centres and, in turn, provide better cognitive outcomes for students.

Comparison of Calculated and Measured Energy Expenditure Determination Methods

Comparison of Calculated and Measured Energy Expenditure Determination Methods

Validity of Apple Watch 6 and Polar A370 for monitoring energy expenditure while resting or performing light to vigorous physical activity.

The purpose of this study was to assess the validity of energy expenditure measurements taken by the Apple Watch 6 and Polar A370 during resting, light- to vigorous-intensity running on the treadmill and ground, and post-exercise of each speed. Randomized cross-over trial. This study included 11 male adults (22.5 ± 1.8 years old). Participants were asked to wear the Apple Watch 6 and the Polar A370 simultaneously to measure energy expenditure under various intensities of physical activities on the treadmill and ground, which were then compared with results from a gas metabolism analysis system. Monitoring energy expenditure for both treadmill and ground, the Apple Watch 6 (range: 13.40-50.34 %) had a higher mean absolute percent error than the Polar A370 (range: 12.74-27.70 %) in resting and running state, while the mean absolute percent error of the Apple Watch 6 (range: 9.71-32.81 %) is smaller than that of the Polar A370 (15.79-43.51 %) in post-exercise. The Apple Watch 6 tends to overestimate energy expenditure, with a mean percent error ranging from -6.61 % to 53.24 %, while the Polar A370 tends to underestimate energy expenditure, with a mean percent error ranging from -3.51 % to 11.33 %. No estimated energy expenditure of both devices fell in the equivalence testing zone. For young adult males, the Apple Watch 6 and Polar A370 provide similar levels of accuracy in monitoring energy expenditure during treadmill and ground running exercise. However, both devices are still inadequate in this regard.

Mechanisms and consequences of weight gain after deep brain stimulation of the subthalamic nucleus in patients with Parkinson’s disease

Body weight gain in combination with metabolic alterations has been observed after deep brain stimulation (DBS) of subthalamic nucleus (STN) in patients with Parkinson’s disease (PD), which potentially counteracts the positive effects of motor improvement. We aimed to identify stimulation-dependent effects on motor activities, body weight, body composition, energy metabolism, and metabolic blood parameters and to determine if these alterations are associated with the local impact of DBS on different STN parcellations. We assessed 14 PD patients who underwent STN DBS (PD-DBS) before as well as 6- and 12-months post-surgery. For control purposes, 18 PD patients under best medical treatment (PD-CON) and 25 healthy controls (H-CON) were also enrolled. Wrist actigraphy, body composition, hormones, and energy expenditure measurements were applied. Electrode placement in the STN was localized, and the local impact of STN DBS was estimated. We found that STN DBS improved motor function by ~ 40% (DBS ON, Med ON). Weight and fat mass increased by ~ 3 kg and ~ 3% in PD-DBS (all P ≤ 0.005). fT3 (P = 0.001) and insulin levels (P = 0.048) increased solely in PD-DBS, whereas growth hormone levels (P = 0.001), daily physical activity, and VO2 during walking were decreased in PD-DBS (all P ≤ 0.002). DBS of the limbic part of the STN was associated with changes in weight and body composition, sedentary activity, insulin levels (all P ≤ 0.040; all r ≥ 0.56), and inversely related to HOMA-IR (P = 0.033; r = − 0.62). Daily physical activity is decreased after STN DBS, which can contribute to weight gain and an unfavorable metabolic profile. We recommend actigraphy devices to provide feedback on daily activities to achieve pre-defined activity goals.