Measurement Of Energy Expenditure Research Articles

Dietary macronutrient composition and its effect on 24-h substrate oxidation: A study of diurnal variations in carbohydrate and fat intake

IntroductionIn recent times, the complexity of food styles and meal content has increased, leading to significant variations in macronutrient composition between meals. This has coincided with a rise in obesity rates. ObjectiveTo determine if a larger variation in macronutrient composition between meals results in lower fat oxidation. MethodsA cross-over study was conducted on 13 healthy young male individuals using whole-body indirect calorimetry to test energy metabolic responses under three conditions: regular meals (R), high-carbohydrate breakfast (CB), or high-fat breakfast (FB), each with different macronutrient contents. R included three meals daily with the same macronutrient composition. CB included a high-carbohydrate meal at breakfast, a high-fat meal at lunch, and a high-carbohydrate meal at dinner. FB included a high-fat meal at breakfast, a high-carbohydrate meal at lunch, and a high-carbohydrate meal at dinner. The daily macronutrient compositions were similar across the three conditions, except CB and FB had larger variations in carbohydrate and fat balance between meals than R. The participants were tested in random order. ResultsThere were no significant differences in the measures of energy expenditure among the three conditions. However, after adjusting for the sleeping respiratory quotient (RQ) on the preceding day, the 24-hour RQ was lower under FB than under R (β=−0.0087, P=0.0077) or CB conditions (β=−0.0078, P=0.016). There was no difference in the magnitude of the 5-hour RQ change from lunch to dinner under the CB condition and in the magnitude of change from breakfast to lunch under the FB condition. ConclusionsA large variation in carbohydrate and fat balance between meals does not decrease daily fat oxidation. A FB may increase daily fat oxidation compared to a CB when the daily food quotient is equal, but this impact may not involve radical acceleration of fat oxidation.

Body Composition and Energy Expenditure in Youth With Spina Bifida: Protocol for a Multisite, Cross-Sectional Study.

Obesity prevalence in youth with spina bifida is higher than in their typically developing peers. Obesity is associated with lifelong medical, psychological, and economic burdens. Successful prevention or treatment of obesity in individuals with spina bifida is compromised by (1) the lack of valid and reliable methods to identify body fat in a clinical setting and (2) limited data on energy expenditure that are necessary to provide daily caloric recommendations. The objectives of this study will be to develop 2 algorithms for use in youth with spina bifida in a clinical setting, one to model body fat and one to predict total daily energy expenditure. In addition, physical activity and dietary intake will be described for the sample. This multisite, prospective, national clinical study will enroll 232 youth with myelomeningocele aged 5 to 18 years (stratified by age and mobility). Participants will be enrolled for 1 week. Data obtained include 4 measures of body composition, up to 5 height measures, a ramped activity protocol, and a nutrition and physical activity screener. Participants will wear an accelerometer for the week. On the final study day, 2 samples of urine or saliva, which complete the doubly labeled water protocol, will be obtained. The analysis will include descriptive statistics, Bland-Altman plots, concordance correlation, and regression analysis. The study received extramural federal funding in July 2019. Data collection was initiated in March 2020. As of April 2024, a total of 143 (female participants: n=76, 53.1%; male participants: n=67, 46.9%) out of 232 participants have been enrolled. Data collection is expected to continue throughout 2024. A no-cost extension until November 2025 will be requested for data analysis and dissemination of findings. This study furthers previous pilot work that confirmed the acceptability and feasibility of obtaining alternate height, body composition, and energy expenditure measures. The findings from this study will enhance screening, prevention, and treatment of abnormal weight status by facilitating the accurate identification of youths' weight status category and recommendations of daily caloric needs for this population that is at higher risk of obesity. Furthermore, the findings have the potential to impact outcomes for youth diagnosed with disabilities other than spina bifida who experience similar challenges related to alterations in body composition or fat distribution or measurement challenges secondary to mobility issues or musculoskeletal problems. DERR1-10.2196/52779.

Modeling approaches for assessing device-based measures of energy expenditure in school-based studies of body weight status

BackgroundObesity has become an important threat to children’s health, with physical and psychological impacts that extend into adulthood. Limited physical activity and sedentary behavior are associated with increased obesity risk. Because children spend approximately 6 h each day in school, researchers increasingly study how obesity is influenced by school-day physical activity and energy expenditure (EE) patterns among school-aged children by using wearable devices that collect data at frequent intervals and generate complex, high-dimensional data. Although clinicians typically define obesity in children as having an age-and sex-adjusted body mass index (BMI) value in the high percentiles, the relationships between school-based physical activity interventions and BMI are analyzed using traditional linear regression models, which are designed to assess the effects of interventions among children with average BMI, limiting insight regarding the effects of interventions among children categorized as overweight or obese.MethodsWe investigate the association between wearable device–based EE measures and age-and sex-adjusted BMI values in data from a cluster-randomized, school-based study. We express and analyze EE levels as both a scalar-valued variable and as a continuous, high-dimensional, functional predictor variable. We investigate the relationship between school-day EE (SDEE) and BMI using four models: a linear mixed-effects model (LMEM), a quantile mixed-effects model (QMEM), a functional mixed-effects model (FMEM), and a functional quantile mixed-effects model (FQMEM). The LMEM and QMEM include SDEE as a summary measure, whereas the FMEM and FQMEM allow for the modeling of SDEE as a high-dimensional covariate. The FMEM and FQMEM allow the influence of the time of day at which physical activity is performed to be assessed, which is not possible using the LMEM or the QMEM. The FMEM assesses how frequently collected SDEE data influences mean BMI, whereas the FQMEM assesses the effects on quantile levels of BMI.ResultsThe LMEM and QMEM detected a statistically significant effect of overall mean SDEE on log (BMI) (the natural logarithm of BMI) after adjusting for intervention, age, race, and sex. The FMEM and FQMEM provided evidence for statistically significant associations between SDEE and log (BMI) for only a short time interval. Being a boy or being assigned a stand-biased desk is associated with a lower log (BMI) than being a girl or being assigned a traditional desk. Across our models, age was not a statistically significant covariate, and white students had significantly lower log (BMI) than non-white students in quantile models, but this significant effect was observed for only the 10th and 50th quantile levels of BMI. The functional regression models allow for additional interpretations of the influence of EE patterns on age-and sex-adjusted BMI, whereas the quantile regression models enable the influence of EE patterns to be assessed across the entire BMI distribution.ConclusionThe FQMEM is recommended when interest lies in assessing how device-monitored SDEE patterns affect children of all body types, as this model is robust and able to assess intervention effects across the full BMI distribution. However, the sample size must be sufficiently large to adequately power determinations of covariate effects across the entire BMI distribution, including the tails.

Optimal nutritional therapy in critically ill patients: a narrative review

Inadequate nutrition delivery remains a pervasive issue in critically ill patients, with significant challenges in accurately measuring nutritional requirements and personalising nutrition. Current medical nutrition therapy is constrained by difficulty in objectively measuring nutritional requirements and patient responses. Both enteral and parenteral nutrition are effective, but achieving and assessing nutritional targets pose substantial challenges. The adoption of computerised nutrition monitoring is on the rise, with future strategies potentially incorporating advanced muscle monitoring tools such as ultrasound and bioelectrical impedance analysis (BIA). Early enteral nutrition has been shown to reduce complications and shorten ICU stays; however, it should be delayed in specific conditions such as gastrointestinal bleeding. When EN is not feasible, PN serves as a safe alternative. Indirect calorimetry offers a method to measure energy expenditure and guide nutritional interventions, though larger trials are necessary to validate its benefits in personalised nutrition strategies. Significant muscle mass loss is prevalent in ICU patients, necessitating optimal amino acid delivery. Protein intake should be tailored to lean mass rather than total body weight, and bedside techniques like BIA and muscle ultrasound can aid in personalising protein delivery. While high protein intake may help mitigate muscle loss, its effect on clinical outcomes remains debated. Further trials are essential to enhance personalised ICU nutrition and improve patient outcomes throughout their ICU and post-ICU care journey.

Feasibility of a laboratory-based protocol for measuring energy expenditure and accelerometer calibration in adults with intellectual disabilities

Adults with intellectual disabilities experience numerous health inequalities. Targeting unhealthy lifestyle behaviours, such as high levels of sedentary behaviour and overweight/obesity, is a priority area for improving the health and adults with intellectual disabilities and reducing inequalities. Energy expenditure is a fundamental component of numerous health behaviours and an essential component of various free-living behaviour measurements, e.g. accelerometry. However, little is known about energy expenditure in adults with intellectual disabilities and no population-specific accelerometer data interpretation methods have been calibrated. The limited research in this area suggests that adults with intellectual disabilities have a higher energy expenditure, which requires further exploration, and could have significant impacts of device calibration. However, due to the complex methods required for measuring energy expenditure, it is essential to first evaluate feasibility and develop an effective protocol. This study aims to test the feasibility of a laboratory-based protocol to enable the measurement of energy expenditure and accelerometer calibration in adults with intellectual disabilities.We aimed to recruit ten adults (≥ 18 years) with intellectual disabilities. The protocol involved a total of nine sedentary, stationary, and physical activities, e.g. sitting, lying down, standing, and treadmill walking. Each activity was for 5 min, with one 10 min lying down activity to measure resting energy expenditure. Breath by breath respiratory gas exchange and accelerometry (ActiGraph and ActivPAL) were measured during each activity. Feasibility was assessed descriptively using recruitment and outcome measurement completion rates, and participant/stakeholder feedback.Ten adults (N = 7 female) with intellectual disabilities participated in this study. The recruitment rate was 50% and 90% completed the protocol and all outcome measures. Therefore, the recruitment strategy and protocol are feasible.This study addresses a significant gap in our knowledge relating to exercise laboratory-based research for adults with intellectual disabilities The findings from this study provide essential data that can be used to inform the development of future protocols to measure energy expenditure and for accelerometer calibration in adults with intellectual disabilities.

It pays to follow the leader: Metabolic cost of flight is lower for trailing birds in small groups

Many bird species commonly aggregate in flocks for reasons ranging from predator defense to navigation. Available evidence suggests that certain types of flocks-the V and echelon formations of large birds-may provide a benefit that reduces the aerodynamic cost of flight, whereas cluster flocks typical of smaller birds may increase flight costs. However, metabolic flight costs have not been directly measured in any of these group flight contexts [Zhang and Lauder, J. Exp. Biol. 226, jeb245617 (2023)]. Here, we measured the energetic benefits of flight in small groups of two or three birds and the requirements for realizing those benefits, using metabolic energy expenditure and flight position measurements from European Starlings flying in a wind tunnel. The starlings continuously varied their relative position during flights but adopted a V formation motif on average, with a modal spanwise and streamwise spacing of [0.81, 0.91] wingspans. As measured via CO2 production, flight costs for follower birds were significantly reduced compared to their individual solo flight benchmarks. However, followers with more positional variability with respect to leaders did less well, even increasing their costs above solo flight. Thus, we directly demonstrate energetic costs and benefits for group flight followers in an experimental context amenable to further investigation of the underlying aerodynamics, wake interactions, and bird characteristics that produce these metabolic effects.

Energy expenditure estimation during activities of daily living in middle-aged and older adults using an accelerometer integrated into a hearing aid.

Accelerometers were traditionally worn on the hip to estimate energy expenditure (EE) during physical activity but are increasingly replaced by products worn on the wrist to enhance wear compliance, despite potential compromises in EE estimation accuracy. In the older population, where the prevalence of hearing loss is higher, a new, integrated option may arise. Thus, this study aimed to investigate the accuracy and precision of EE estimates using an accelerometer integrated into a hearing aid and compare its performance with sensors simultaneously worn on the wrist and hip. Sixty middle-aged to older adults (average age 64.0 ± 8.0 years, 48% female) participated. They performed a 20-min resting energy expenditure measurement (after overnight fast) followed by a standardized breakfast and 13 different activities of daily living, 12 of them were individually selected from a set of 35 activities, ranging from sedentary and low intensity to more dynamic and physically demanding activities. Using indirect calorimetry as a reference for the metabolic equivalent of task (MET), we compared the EE estimations made using a hearing aid integrated device (Audéo) against those of a research device worn on the hip (ZurichMove) and consumer devices positioned on the wrist (Garmin and Fitbit). Class-estimated and class-known models were used to evaluate the accuracy and precision of EE estimates via Bland-Altman analyses. The findings reveal a mean bias and 95% limit of agreement for Audéo (class-estimated model) of -0.23 ± 3.33 METs, indicating a slight advantage over wrist-worn consumer devices (Garmin: -0.64 ± 3.53 METs and Fitbit: -0.67 ± 3.40 METs). Class-know models reveal a comparable performance between Audéo (-0.21 ± 2.51 METs) and ZurichMove (-0.13 ± 2.49 METs). Sub-analyses show substantial variability in accuracy for different activities and good accuracy when activities are averaged over a typical day's usage of 10 h (+61 ± 302 kcal). This study shows the potential of hearing aid-integrated accelerometers in accurately estimating EE across a wide range of activities in the target demographic, while also highlighting the necessity for ongoing optimization efforts considering precision limitations observed across both consumer and research devices.

Examining and Comparing the Energy Expenditure of Two Modes of a Virtual Reality Fitness Game (Supernatural): Indirect Calorimetry Study.

The effectiveness of virtual reality (VR) fitness games as a form of moderate to vigorous physical activity has yet to be thoroughly quantified through gold standard energy expenditure measures. The purpose of this study was to examine the energy expenditure of 2 medium-intensity modes ("Flow and "Boxing") of a VR fitness game, Supernatural, using indirect calorimetry. Indirect calorimetry was used to examine relative and objective maximal oxygen consumption (VO2 max), metabolic equivalents of task (METs), and calories burned during medium-intensity bouts of both Flow and Boxing gameplay modes in young (mean age 25.42, SD 3.25 years), active individuals (n=12 female and n=11 male). METs and calories were also compared using a triaxial waist-worn accelerometer, an Apple smartwatch, and a VR headset. Mood states were assessed pre- and postbout using the shortened Profile of Mood States Questionnaire. Paired 2-tailed t tests were used to examine differences in game modes, between sexes, and pre-post exercise sessions. Objective and relative VO2 max averaged 1.93 (SD 0.44) L/min and 27.61 (SD 5.60) mL/kg/min, respectively, between modes. Flow (mean 8.2, SD 1.54 METs) and Boxing (mean 7.6, SD 1.66 METs) are both classified as high energy expenditure, vigorous activities. Calorie expenditure data of the accelerometer and VR headset differed significantly from the metabolic cart. Mood changes pre- to post exercise were consistent with expected values for moderate- to vigorous-intensity physical activity, with participants reporting that they felt more "active," "full of pep," "vigorous," and "lively" (P<.05) following bouts. Male individuals reported higher objective oxygen consumption (VO2) for both Flow and Boxing modes; no other sex-specific differences were observed. Both Flow and Boxing gameplay modes of Supernatural classify as vigorous physical activity and demonstrate the potential to promote mental and physical health benefits. Supernatural may be an effective exercise modality in a VO2 training program.

Effects of Partial Knockout of Skeletal Muscle Dynamin-Related Protein 1 on Skeletal Muscle Characteristics in Lean and Obese Mice

Dynamin-related protein 1 (Drp1) is a key regulator of mitochondrial fission and plays an essential role in maintaining skeletal muscle homeostasis. Recent studies reported muscle atrophy in mice when skeletal muscle Drp1 content was reduced. However, whether such atrophic phenotype also exists in diet-induced obese mice remains unknown. We recently reported that reducing skeletal muscle Drp1 resulted in improved whole-body glucose homeostasis and insulin sensitivity in diet-induced obese mice, but not lean healthy mice, suggesting Drp1 may exert divergent effects on physiological phenotypes under different conditions. OBJECTIVE: To determine the effects of partial knockout of skeletal muscle-specific heterozygous Drp1 (mDrp1+/−) on body composition, energy expenditure and skeletal muscle physiology in lean and obese mice. HYPOTHESIS: mDrp1+/− exhibits divergent alterations in physiological characteristics between lean healthy and obese mice. Methods: Tamoxifen-inducible mDrp1+/− mouse model was generated. Nine-week-old male and female mDrp1+/− and wildtype (WT) mice (n=6-8/group) were fed with either a high-fat diet (HFD) or low-fat diet (LFD) for four weeks, received tamoxifen injections, and remained on their respective diet for another four to six weeks. A DXA scan was conducted to measure body composition. Mice were housed in Promethion metabolic cages for 48 hours to measure energy expenditure. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles were used for assessing muscle cross sectional area (CSA) and contractility. Results: HFD-fed mice had significantly higher percentage of body fat ( p = 0.045) and lower respiratory exchange ratio ( p &lt;0.0001) than LFD-fed mice, regardless of genotype. Regarding skeletal muscle characteristics, SOL from mDrp1+/− mice exhibited larger CSA ( p = 0.052) than WT mice, regardless of diet. However, there were no differences in muscle force or fatigue resistance in SOL between groups. In contrast, EDL muscle isolated from mDrp1+/− mice fed with HFD had greater muscle force than WT mice, but interestingly the force was lower in mDrp1+/−/LFD mice than WT/LFD mice (genotype x diet interaction effect, p = 0.001). Consistently, a significant interaction was found in both twitch and tetanic rate of force development and relaxation rates (genotype x diet interaction effect, p = 0.022, p = 0.033, p = 0.040, and p = 0.020, respectively). There was no difference in EDL muscle CSA between groups. CONCLUSION: Our data suggests that partial knockout of Drp1 in skeletal muscle induced divergent effects on CSA, force production and fatigability between diet induced obese and lean healthy mice. This study was supported by the National Institute of Health (R15DK131512). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Methods to estimate body temperature and energy expenditure dynamics in fed and fasted laboratory mice: effects of sleep deprivation and light exposure

Monitoring body temperature and energy expenditure in freely-moving laboratory mice remains a powerful methodology used widely across a variety of disciplines–including circadian biology, sleep research, metabolic phenotyping, and the study of body temperature regulation. Some of the most pronounced changes in body temperature are observed when small heterothermic species reduce their body temperature during daily torpor. Daily torpor is an energy saving strategy characterized by dramatic reductions in body temperature employed by mice and other species when challenged to meet energetic demands. Typical measurements used to describe daily torpor are the measurement of core body temperature and energy expenditure. These approaches can have drawbacks and developing alternatives for these techniques provides options that can be beneficial both from an animal-welfare and study-complexity perspective. First, this paper presents and assesses a method to estimate core body temperature based on measurements of subcutaneous body temperature, and second, a separate approach to better estimate energy expenditure during daily torpor based on core body temperature. Third, the effects of light exposure during the habitual dark phase and sleep deprivation during the light period on body temperature dynamics were tested preliminary in fed and fasted mice. Together, the here-published approaches and datasets can be used in the future to assess body temperature and metabolism in freely-moving laboratory mice.

Impaired metabolic flexibility to fasting is associated with increased ad libitum energy intake in healthy adults.

We investigated how changes in 24-h respiratory exchange ratio (RER) and substrate oxidation during fasting versus an energy balance condition influence subsequent ad libitum food intake. Forty-four healthy, weight-stable volunteers (30 male and 14 female; mean [SD], age 39.3 [11.0] years; BMI 31.7 [8.3] kg/m2) underwent 24-h energy expenditure measurements in a respiratory chamber during energy balance (50% carbohydrate, 30% fat, and 20% protein) and 24-h fasting. Immediately after each chamber stay, participants were allowed 24-h ad libitum food intake from computerized vending machines. Twenty-four-hour RER decreased by 9.4% (95% CI: -10.4% to -8.5%; p < 0.0001) during fasting compared to energy balance, reflecting a decrease in carbohydrate oxidation (mean [SD], -2.6 [0.8] MJ/day; p < 0.0001) and an increase in lipid oxidation (2.3 [0.9] MJ/day; p < 0.0001). Changes in 24-h RER and carbohydrate oxidation in response to fasting were correlated with the subsequent energy intake such that smaller decreases in fasting 24-h RER and carbohydrate oxidation, but not lipid oxidation, were associated with greater energy intake after fasting (r = 0.31, p = 0.04; r = 0.40, p = 0.007; and r = -0.27, p = 0.07, respectively). Impaired metabolic flexibility to fasting, reflected by an inability to transition away from carbohydrate oxidation, is linked with increased energy intake.

Alpha-2-adrenergic agonists reduce resting energy expenditure in humans during external cooling

ABSTRACT Intravenous alpha-2-adrenergic receptor agonists reduce energy expenditure and lower the temperature when shivering begins in humans, allowing a decrease in core body temperature. Because there are few data about similar effects from oral drugs, we tested whether single oral doses of the sedative dexmedetomidine (1 µg/kg sublingual or 4 µg/kg swallowed) or the muscle relaxant tizanidine (8 mg or 16 mg), combined with surface cooling, reduce energy expenditure and core body temperature in humans. A total of 26 healthy participants completed 41 one-day laboratory studies measuring core body temperature using an ingested telemetry capsule and measuring energy expenditure using indirect calorimetry for up to 6 hours after drug ingestion. Dexmedetomidine induced a median 13% – 19% peak reduction and tizanidine induced a median 15% – 22% peak reduction in energy expenditure relative to baseline. Core body temperature decreased a median of 0.5°C – 0.6°C and 0.5°C – 0.7°C respectively. Decreases in temperature occurred after peak reductions in energy expenditure. Energy expenditure increased with a decrease in core temperature in control participants but did not occur after 4 µg/kg dexmedetomidine or 16 mg tizanidine. Plasma levels of dexmedetomidine but not tizanidine were related to mean temperature change. Decreases in heart rate, blood pressure, respiratory rate, cardiac stroke volume index, and cardiac index were associated with the change in metabolic rate after higher drug doses. We conclude that both oral dexmedetomidine and oral tizanidine reduce energy expenditure and allow decrease in core temperature in humans.

RESULTS OF DAILY ENERGY CONSUMPTION OF WORKERS OF TOBACCO PRODUCTION ENTERPRISE

This study reviewed common methods used to measure energy expenditure and body composition. The study also discusses genetic and hormonal factors that regulate energy balance, the concept of a healthy weight, and appetite and body composition.

Energy Expenditure, a New Tool for Monitoring Surgical Stress in Colorectal Oncological Patients: A Prospective, Monocentric Study.

Surgical stress response in colorectal surgery consists of a neurohormonal and an immunological response and influences oncological outcomes. The intensity of surgical trauma influences mortality, morbidity, and metastasis' occurrence in colorectal neoplasia. Energy expenditure (EE) stands for the body's energy consumed to keep its homeostasis and can be either calculated or measured by direct or indirect calorimetry. The present study attempted to evaluate surgical stress response using EE measurement and compare it to the postoperative cortisol dynamic. A prospective, monocentric study was conducted over a period of one year in the Anesthesiology Department including 21 patients from whom serum cortisol values were collected in the preoperative periodand on the first postoperative day, and EE was measured and recorded every 15 minutes throughout surgery using the indirect calorimetry method. The studycompared EE values' dynamic registered 30 minutes after intubation and 30 minutes before extubating (after abdominal closure) to cortisol perioperative dynamic. We enrolled 21 patients and84 measurements were recorded, 42 probes of serum cortisoland 42 measurements of EE. The mean value of the first measurement of serum cortisol was 13.60±3.6 µgand the second was 16.21±6.52 µg. The average value of the first EE recording was 1273.9±278 kcal and 1463.4±398.2 kcal of the second recording. The bivariate analysis performed showed a good correlation between cortisol variation and EE's variation (Spearman coefficient=0.666, p<0.001, CI=0.285, 0.865). In nine cases (42.85%), cortisol value at 24 hours reached the baseline or below the baselines preoperative value. In eight cases (38.09%), patients' EE at the end of the surgery was lower than that recorded at the beginning of the surgery. Intraoperative EE variation correlated well with cortisol perioperative dynamic and stood out in this study as a valuable and accessible predictor of surgical stress in colorectal surgery.

Dissolved Oxygen Relevantly Contributes to Systemic Oxygenation During Venovenous Extracorporeal Membrane Oxygenation Support.

When determining extracorporeal oxygen transfer (V ML O 2 ) during venovenous extracorporeal membrane oxygenation (VV ECMO) dissolved oxygen is often considered to play a subordinate role due to its poor solubility in blood plasma. This study was designed to assess the impact of dissolved oxygen on systemic oxygenation in patients with acute respiratory distress syndrome (ARDS) on VV ECMO support by differentiating between dissolved and hemoglobin-bound extracorporeal oxygen transfer. We calculated both extracorporeal oxygen transfer based on blood gas analysis using the measuring energy expenditure in extracorporeal lung support patients (MEEP) protocol and measured oxygen uptake by the native lung with indirect calorimetry. Over 20% of V ML O 2 and over 10% of overall oxygen uptake (VO 2 total ) were realized as dissolved oxygen. The transfer of dissolved oxygen mainly depended on ECMO blood flow (BF ML ). In patients with severely impaired lung function dissolved oxygen accounted for up to 28% of VO 2 total . A clinically relevant amount of oxygen is transferred as physically dissolved fraction, which therefore needs to be considered when determining membrane lung function, manage ECMO settings or guiding the weaning procedure.

Association between protocol change to a higher-protein formula with lower energy targets and nutrient delivery in critically ill patients with COVID-19: A retrospective cohort study.

Guidelines recommend prioritizing protein provision while avoiding excessive energy delivery to critically ill patients with coronavirus disease 2019 (COVID-19), but there are no prospective studies evaluating such a targeted approach in this group. We aimed to evaluate the effect of a "higher-protein formula protocol" on protein, energy, and volume delivery when compared with standard nutrition protocol. This was a retrospective cohort study of adult patients with COVID-19 who received mechanical ventilation for >72 h and enteral nutrition. Before October 2021, the standard nutrition protocol for patients was 0.7 ml/kg/h ideal body weight (IBW) of a 63 g/L protein and 1250 kcal/L formula. From October 2021, we implemented a higher-protein formula protocol for patients with COVID-19. The initial prescription was 0.5 ml/kg/h IBW of a 100 g/L protein and 1260 kcal/L formula with greater emphasis on energy targets being directed by indirect calorimetry when possible. Measured outcomes included protein, energy, and volume delivered. There were 114 participants (standard protocol, 48; higher-protein protocol, 66) with 1324 days of nutrition support. The median (95% CI) differences in protein, energy, and volume delivery between targeted and standard protocol periods were 0.08 g/kg/day (-0.02 to 0.18 g/kg/day), -1.71 kcal/kg/day (-3.64 to 0.21 kcal/kg/day) and -1.5 ml/kg/day (-2.9 to -0.1 ml/kg/day). Thirty-three patients (standard protocol, 7; higher-protein protocol, 26) had 44 indirect calorimetry assessments. There was no difference in measured energy expenditure over time (increased by 0.49 kcal/kg/day [-0.89 to 1.88 kcal/kg/day]). Implementation of a higher-protein formula protocol to patients with COVID-19 modestly reduced volume administration without impacting protein and energy delivery.

Measurement of Energy Expenditure by Indirect Calorimetry with a Whole-Room Calorimeter.

Energy plays a vital role in biological processes. To assess energy metabolism status in a large population cohort, the standard operating procedure for measuring energy expenditure measurement using a whole-room calorimeter was purposed in this study. This protocol illustrates the procedure and specific details for validating methanol burning and evaluating the metabolic status of volunteers. In metabolic status evaluation, the (1) O2 consumption, (2) CO2 production, (3) energy expenditure, and (4) respiratory exchange ratio were first measured at resting and provided as basic phenotype items in Human Phenotype Atlas. Besides, it includes the procedure and results for measuring exercise-related activity thermogenesis and evaluating the impact of environmental temperature on energy metabolism. These results demonstrate the broader utility of the whole-room calorimeter. The implementation of this protocol is expected to enhance the data comparability in Human Phenotype Atla and provide a valuable reference for metabolism-related studies.

Design and conduct of a randomized controlled feeding trial in a residential setting with mitigation for COVID-19

BackgroundEvaluating effects of different macronutrient diets in randomized trials requires well defined infrastructure and rigorous methods to ensure intervention fidelity and adherence. MethodsThis controlled feeding study comprised two phases. During a Run-in phase (14–15 weeks), study participants (18–50 years, BMI, ≥27 kg/m2) consumed a very-low-carbohydrate (VLC) diet, with home delivery of prepared meals, at an energy level to promote 15 ± 3% weight loss. During a Residential phase (13 weeks), participants resided at a conference center. They received a eucaloric VLC diet for three weeks and then were randomized to isocaloric test diets for 10 weeks: VLC (5% energy from carbohydrate, 77% from fat), high-carbohydrate (HC)-Starch (57%, 25%; including 20% energy from refined grains), or HC-Sugar (57%, 25%; including 20% sugar). Outcomes included measures of body composition and energy expenditure, chronic disease risk factors, and variables pertaining to physiological mechanisms. Six cores provided infrastructure for implementing standardized protocols: Recruitment, Diet and Meal Production, Participant Support, Assessments, Regulatory Affairs and Data Management, and Statistics. The first participants were enrolled in May 2018. Participants residing at the conference center at the start of the COVID-19 pandemic completed the study, with each core implementing mitigation plans. ResultsBefore early shutdown, 77 participants were randomized, and 70 completed the trial (65% of planned completion). Process measures indicated integrity to protocols for weighing menu items, within narrow tolerance limits, and participant adherence, assessed by direct observation and continuous glucose monitoring. ConclusionAvailable data will inform future research, albeit with less statistical power than originally planned.

Determination of energy requirements after minor burns using indirect calorimetry: A descriptive cohort study.

Minor burns could be associated with moderate hypermetabolism. In this study, the primary outcome was measured energy expenditure (mEE) determined by indirect calorimetry in patients with minor burns. We also compared mEE with predictive values and actual energy intakes. Adults with minor burns exclusively treated on an outpatient basis were included. During the week following injury, a dietitian performed indirect calorimetry (Q-NRG in canopy mode), calculated the estimated energy expenditure (eEE) based on the Harris-Benedict (HB) and Henry formulas, and evaluated daily energy intakes using a food anamnesis. Forty-nine patients (59.2% male; median age: 35 [interquartile range: 29-46.5] years; body mass index [BMI]: 26.2 [22.3-29.6] kg/m2; burn surface area [BSA]: 1.5% [1%-2%]) were included 4 (2-6) days after injury. The mEE was 1863 (1568-2199) kcal or 25 (22.4-28.5) kcal/kg and 1838 (1686-2026) kcal or 26.1 (23.7-27.7) kcal/kg in patients who were respectively fasting for >10 h or not (P = 0.991 or P = 0.805). The total mEE was 104% (95%-116%) and 108% (99%-122%) of the total eEE using the HB and Henry formulas, respectively, with diet-induced thermogenesis and physical activity level. Hypermetabolism (ie, oxygen consumption at rest ≥3.5 ml/kg/min) was observed in 21/49 (42.9%) patients. Energy intakes corresponded to 71% (60%-86%) of the total mEE. Performing indirect calorimetry in adults with minor burns revealed that ≥40% of the tested adults presented a hypermetabolism and that their mEE was not covered by their energy intakes.

Comparative Analysis Of Energy Expenditure Assessments From The Graded Exercise Test Vs. Galaxy Watch And Apple Watch In Korean College Students During A 30-minute Workout: A Pilot Study

OBJECTIVES In the modern era, there is heightened interest in understanding energy expenditure during exercise. Consequently, wearable devices such as the Galaxy Watch and Apple Watch have emerged as pivotal tools for daily health monitoring, given their convenience and increasing popularity. This study aimed to compare the calculated energy expenditure derived from the graded exercise test with readings from Galaxy and Apple Watches during a 30-min exercise session among Korean university students. Through this, we anticipate offering both motivation and clear insights into energy expenditure, thereby potentially aiding in weight management strategies for contemporary individuals.METHODS This study involved 27 college students from Korea National University of Transportation in Chungcheongbuk-do, Korea. We utilized COSMED's exercise load respiratory gas analysis system (Quark- CPET, COSMED, Rome, Italy), along with the Galaxy Watch (Galaxy Watch 5, Samsung, Seoul, Korea) and the Apple Watch (Apple watch series 5, Apple, Cupertino, USA) for measurements. Energy expenditure was monitored in real-time every 5 min throughout the 30-min exercise session. For statistical evaluations, we employed a one-way analysis of variance. Subsequent post-tests utilized the Tukey post-hoc test and Pearson correlation, with a significance level set at p&lt;0.05.RESULTS Initially, no statistically significant difference emerged between energy expenditure readings from the graded exercise test and those from the Galaxy Watch across all time intervals: 5, 10, 15, 20, 25, and 30 min (p&gt;0.05). Conversely, a notable difference was observed when comparing energy expenditure data from the graded exercise test to that of the Apple Watch for time intervals of 10, 15, 20, 25, and 30 min (p&gt;0.05), although the 5-min interval did not exhibit a significant difference (p&gt;0.05). Furthermore, a robust positive correlation was evident between the energy expenditure values derived from the graded exercise test and those from both the Galaxy Watch (r=0.952, p&lt;0.001) and the Apple Watch (r=0.917, p&lt;0.001).CONCLUSIONS Both devices demonstrated high reliability in calculating energy expenditure. Notably, the Galaxy Watch exhibited a more precise calculation compared to the Apple Watch, with a relative reliability margin of 3.5% higher. For individuals, especially those struggling with obesity, precise wearable devices that accurately reflect energy consumption can significantly boost motivation for exercise. Consequently, this study lays a foundation for future advancements in energy expenditure measurement tools, emphasizing enhanced convenience, reliability, and mobility.