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Purpose: Nutrition is of paramount importance in critically ill trauma patients. However, adequate supply is difficult to achieve, as caloric requirements are unknown. This study investigated caloric requirements over time, based on indirect calorimetry, in critically ill trauma patients. Methods: Retrospective cohort study at a tertiary trauma center including critically ill trauma patients who underwent indirect calorimetry 2012–2019. Caloric requirements were assessed as resting energy expenditure (REE) during the intensive care unit stay up to 28 days and analyzed in patient-clustered linear regression analysis. Results: A total of 129 patients were included. Median REE per day was 2376 kcal. The caloric intake did not meet REE at any time with a median daily deficit of 1167 kcal. In univariable analysis, ISS was not significantly associated with REE over time (RC 0.03, p = 0.600). Multivariable analysis revealed a significant REE increase (RC 0.62, p < 0.001) and subsequent decrease (RC – 0.03, p < 0.001) over time. Age < 65 years (RC 2.07, p = 0.018), male sex (RC 4.38, p < 0.001), and BMI ≥ 35 kg/m2 (RC 6.94, p < 0.001) were identified as independent predictors for higher REE over time. Severe head trauma was associated with lower REE over time (RC – 2.10, p = 0.030). Conclusion: In critically ill trauma patients, caloric requirements significantly increased and subsequently decreased over time. Younger age, male sex and higher BMI were identified as independent predictors for higher caloric requirements, whereas severe head trauma was associated with lower caloric requirements over time. These results support the use of IC and will help to adjust nutritional support in critically ill trauma patients. [ABSTRACT FROM AUTHOR]

Background & Aims: In recent times, the complexity of food styles and meal content has increased, leading to significant variations in macronutrient composition between meals. This phenomenon has coincided with a rise in obesity rates. We aimed to determine whether a large variation in macronutrient composition between meals results in reduced fat oxidation., Methods: A cross-over study was conducted with 13 healthy young men, using whole-body indirect calorimetry to test 24-h energy metabolic responses under three conditions: regular meals (R), high-carbohydrate breakfast (CB), or high-fat breakfast (FB), each with different macronutrient contents. The R condition included three meals daily with the same macronutrient composition. The CB condition included a high-carbohydrate meal at breakfast, high-fat meal at lunch, and high-carbohydrate meal at dinner. The FB condition included a high-fat meal at breakfast, high-carbohydrate meal at lunch, and high-carbohydrate meal at dinner. The daily macronutrient compositions were similar across the three conditions, except that CB and FB had larger variations in carbohydrate-fat balance between meals than R. The participants were tested in random order. During the dietary intervention, we compared 24-h whole-body metabolic parameters, including substrate oxidation (e.g., 24 h respiratory quotient [RQ])., Results: No significant differences were observed in the measures of energy expenditure among the three conditions. However, after adjusting for the sleeping RQ on a preceding day, the estimated 24hRQ was lower under the FB condition (0.845) than under the R (0.854, P = 0.0077 vs. FB) and CB conditions (0.853, P = 0.016 vs. FB). No difference was observed in the magnitude of the 5-h RQ change from lunch to dinner under the CB condition and in the magnitude of change from breakfast to lunch under the FB condition., Conclusions: A large variation in the carbohydrate-fat balance between meals does not decrease daily fat oxidation. An FB may increase daily fat oxidation compared to a CB when the daily food quotient is constant, but this increase may not be owing to the upregulation of fat burning on a daily basis., Competing Interests: Conflict of interest None of the authors has a direct conflict of interest to declare., (Copyright © 2024 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Purpose of Review: Accurate assessment of dietary intake, especially energy and protein intake, is crucial for optimizing nutritional care and outcomes in patients with cancer. Validation of dietary assessment methods is necessary to ensure accuracy, but the validity of these methods in patients with cancer, and especially in those with cancer cachexia, is uncertain. Validating nutritional intake is complex because of the variety of dietary methods, lack of a gold standard method, and diverse validation measures. Here, we review the literature on validations of dietary intake methods in patients with cancer, including those with cachexia, and highlight the gap between current validation efforts and the need for accurate dietary assessment methods in this population., Recent Findings: We analyzed eight studies involving 1479 patients with cancer to evaluate the accuracy and reliability of 24-hour recalls, food records, and food frequency questionnaires in estimating energy and protein intake. We discuss validation methods, including comparison with biomarkers, indirect calorimetry, and relative validation of dietary intake methods., Summary: Few have validated dietary intake methods against objective markers in patients with cancer. While food records and 24-hour recalls show potential accuracy for energy and protein intake, this may be compromised in hypermetabolic patients. Additionally, under- and overreporting of intake may be less frequent, and the reliability of urinary nitrogen as a protein intake marker in patients with cachexia needs further investigation. Accurate dietary assessment is important for enhancing nutritional care outcomes in cachexia trials, requiring validation at multiple time points throughout the cancer trajectory., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: The effect of eccentric exercise-induced muscle damage (EIMD) on cycling efficiency is unknown. The aim of the present study was to assess the effect of EIMD on gross and delta efficiency and the cardiopulmonary responses to cycle ergometry., Methods: Twenty-one recreational athletes performed cycling at 70%, 90%, and 110% of the gas exchange threshold (GET) under control conditions (Control) and 24 h following an eccentric damaging protocol (Damage). Knee extensor isometric maximal voluntary contraction, potentiated twitch ( Qtw,pot ), and voluntary activation were assessed before Control and Damage. Gross and delta efficiency were assessed using indirect calorimetry, and cardiopulmonary responses were measured at each power output. Electromyography root-mean-square (EMG RMS ) during cycling was also determined., Results: Maximal voluntary contraction was 25% ± 18% lower for Damage than Control ( P < 0.001). Gross efficiency was lower for Damage than Control ( P < 0.001) by 0.55% ± 0.79%, 0.59% ± 0.73%, and 0.60% ± 0.87% for 70%, 90%, and 110% GET, respectively. Delta efficiency was unchanged between conditions ( P = 0.513). Concurrently, cycling EMG RMS was higher for Damage than Control ( P = 0.004). An intensity-dependent increase in breath frequency and V̇ E /V̇CO 2 was found, which were higher for Damage only at 110% GET ( P ≤ 0.019)., Conclusions: Thus, gross efficiency is reduced following EIMD. The concurrently higher EMG RMS suggests that increases in muscle activation in the presence of EIMD might have contributed to reduced gross efficiency. The lack of change in delta efficiency might relate to its poor reliability hindering the ability to detect change. The findings also show that EIMD-associated hyperventilation is dependent on exercise intensity, which might relate to increases in central command with EIMD., (Copyright © 2024 by the American College of Sports Medicine.)

Purpose : In this study we evaluated the reliability of blood lactate levels (BLa), energy expenditure and substrate utilization during prolonged exercise at the intensity that elicits maximal fat oxidation (FATmax). Furthermore, we investigated the accuracy of a single graded exercise test (GXT) for predicting energy metabolism at FATmax. Methods : Seventeen young men with obesity (26 ± 6 years; 36.4 ± 7.2 %body fat) performed a GXT on a treadmill in a fasted state (10-12 h) for the assessment of FATmax and cardiorespiratory fitness. Afterward, each subject performed two additional prolonged FATmax trials (102 ± 11 beats·min -1 ; 60-min) separated by 7 days. Indirect calorimetry was used for the assessment of energy expenditure and substrate utilization kinetics whereas capillary blood samples were taken for the measurement of BLa. Results : The BLa (limits of agreement (LoA): -1.2 to 0.8 mmol∙L -1 ; p = 1.0), fat utilization (LoA: -8.0 to 13.4 g∙h -1 ; p = 0.06), and carbohydrate utilization (LoA: -27.6 to 22.4 g∙h -1 ; p = 0.41) showed a good agreement whereas a modest systematic bias was found for energy expenditure (LoA: -16811 to 33355 kJ∙h -1 ; p < 0.05). All the aforementioned parameters showed a moderate to good reliability (Intraclass correlation coefficient: 0.67-0.92). The GXT overestimated fat (~46%) and carbohydrate (~26%) utilization as well as energy expenditure (36%) during steady-state exercise at FATmax. Conversely the GXT underestimated BLa (~28%). Conclusion : a single GXT cannot be used for an accurate prediction of energy metabolism during prolonged exercise in men with obesity. Thus, an additional steady-state FATmax trial (40-60 min) should be performed for a tailored and precise exercise prescription.

This study investigated the effect of 4 days low energy availability (LEA) on physiological markers and mood states in male endurance runners. Twelve participants (mean (standard deviation); age: 25.8 (3.8) years; fat-free mass (FFM): 52.8 (5.5) kg) completed three 4-day conditions: adequate energy availability (AEA): 45 kcal/kg FFM/day; LEA1: 30 kcal/kg FFM/day; and LEA2: 15 kcal/kg FFM/day, in a randomized order. Participants ran on a treadmill at 65% of V̇O 2 max until they expended 15 kcal/kg FFM/day of energy. Energy intake was adjusted to achieve the desired energy availability. Pre- and post-measurements of bone turnover, metabolism, testosterone and estradiol (plasma), resting metabolic rate (indirect calorimetry), and mood states (Brunel Mood Scale) were assessed. The results reported a significant decrease in testosterone (condition × time interaction, p  = 0.03) occurred on LEA2 (Pre: 23.8 (7.0) nmol/L vs. Post: 20.3 (7.7) nmol/L) compared with AEA (Pre: 22.9 (5.5) nmol/L vs. Post: 23.3 (6.1) nmol/L) or LEA1 (Pre: 23.6 (8.6) nmol/L vs. Post: 20.9 (8.8) nmol/L). Fatigue level significantly increased (condition × time interaction, p  = 0.02) in LEA2 (Pre: 3.5 (1.7) vs. Post: 6.5 (2.9)) but did not change in AEA (Pre: 2.8 (1.5) vs. Post: 2.5 (2.7)) or LEA1 (Pre: 2.8(2.4) vs. Post: 2.9 (2.0)). Other measures were unaffected by the interventions. In conclusion, this study suggests that testosterone and fatigue may serve as early indicators of LEA in male runners. However, other physiological markers and mood states appeared largely unaffected, aligning with existing literature indicating minimal disruption of physiological functions during acute LEA in male athletes. Study registration: Australian New Zealand Clinical Trials Registry (Trial No.: 381278)., Competing Interests: The authors declare there are no competing interests.

Objectives: To compare different types of activity trackers recording physical activity energy expenditure (PAEE) and examine their criterion validity against indirect calorimetry (IC) as the gold standard in adults over 60 years of age with a special focus on women with cardiovascular risk., Design: Synchronous registrations of PAEE were performed with up to four different devices to determine criterion validity against IC while participants performed a protocol of simulated activities in a laboratory setting., Method: Thirty-four participants (25 women, 9 men) with at least a light cardiac risk performed a protocol of simulated activities in a laboratory setting (daily living activities, cycle ergometer test). PAEE was simultaneously assessed by IC, two research-grade activity trackers (ActiGraph-wGT3X-BT and Actiheart-4) and two consumer-level activity trackers (OMRON pedometer and Fitbit Charge-3). Tracker-derived PAEE was compared with PAEE calculated from IC descriptively and by Bland-Altman plots., Results: The ActiGraph (0.7 ± 0.4 kcal/min), the Actiheart (1.1 ± 0.6 kcal/min) and the OMRON (0.8 ± 0.6 kcal/min) underestimated, while the Fitbit (3.4 ± 1.2 kcal/min) overestimated PAEE compared to IC-PAEE (2.0 ± 0.5 kcal/min). The Bland-Altman limits of agreement (LoA) against IC were +0.5/+2.2 kcal/min for the ActiGraph, -0.3/+2.1 kcal/min for the Actiheart, -3.7/+1.0 kcal/min for the Fitbit, and -0.5/+2.9 kcal/min for the OMRON. The magnitude of the deviation varied considerably depending on the activity (e.g. walking, cleaning, cycle ergometer test)., Conclusions: The research-grade activity trackers estimated PAEE with higher validity than the commercially available activity trackers. The partly very wide LoA have to be critically considered when assessing PAEE in the context of health service research, as individual Physical Activity behaviour may be under- or overestimated., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rieckmann et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Total energy expenditure (TEE) is the total energy expended by an individual to sustain life, activities, and growth. TEE is formed by four components: resting energy expenditure (REE), activity energy expenditure (AEE), growth-related energy expenditure (GEE), and the thermic effect of feeding (TEF). Some energy expenditure (EE) components may change throughout childhood and cannot be reliably estimated using prediction formulae., Objective: To summarize measured TEE components as reported in the literature in healthy and critically ill children., Methods: We searched MEDLINE, EMBASE, and CINAHL for studies published between 1946 and 7 September 2023. The primary outcome was energy expenditure. Included studies were published in English and measured one or more of TEE, AEE, GEE, and TEF with Indirect Calorimetry or Doubly Labeled Water in participants between 1 month and 18 years of age. We excluded studies reporting only REE or using predictive equations. Following abstraction, reported values were converted into kcal/kg/day or kcal/day as possible. Weighted mean values were calculated using median or means of EE measurements., Results: We found 138 studies, 8163 patients, and 16,636 eligible measurements. The median (IQR) study sample size was 20 (12, 35) patients. TEE was the most evaluated component. The median (IQR) TEE in infants was 73.1 (67.0, 76.5), in children 78.0 (66.0, 81.3), and in adolescents was 44.2 (41.8, 51.9) kcal/kg/day. Very few studies reported on GEE and TEF., Conclusions: This is one of the first studies that summarizes components of total energy expenditure in different pediatric age groups in healthy and critically ill children. Growth- and feeding-associated energy expenditure are poorly reported in healthy children, while all components of TEE (except REE) are poorly reported in critically ill children.

To establish the criterion-assessed energy and fluid requirements of female netball players, 13 adult players from a senior Netball Super League squad were assessed over 14 days in a cross-sectional design, representing a two- and one-match microcycle, respectively. Total energy expenditure (TEE) and water turnover (WT) were measured by doubly labeled water. Resting and activity energy expenditure were measured by indirect calorimetry and Actiheart, respectively. Mean 14-day TEE was 13.46 ± 1.20 MJ day -1 (95% CI, 12.63-14.39 MJ day -1 ). Resting energy expenditure was 6.53 ± 0.60 MJ day -1 (95% CI, 6.17-6.89 MJ day -1 ). Physical activity level was 2.07 ± 0.19 arbitrary units (AU) (95% CI, 1.95-2.18 AU). Mean WT was 4.1 ± 0.9 L day -1 (95% CI, 3.6-4.7 L day -1 ). Match days led to significantly greater TEE than training (+2.85 ± 0.70 MJ day -1 ; 95% CI, +1.00- +4.70 MJ day -1 ; p = 0.002) and rest (+4.85 ± 0.70 MJ day -1 ; 95% CI, +3.13-+6.56 MJ day -1 ; p < 0.001) days. Matches led to significantly greater energy expenditure (+1.85 ± 1.27 MJ; 95% CI, +0.95-+2.76 MJ day -1 ; p = 0.001) than court-based training sessions. There was no significant difference in TEE (+0.03 ± 0.35 MJ day -1 ; 95% CI, -0.74-+0.80 MJ day -1 ; p = 0.936) across weeks. Calibrated Actiheart 5 monitors underestimated TEE (-1.92 ± 1.21 MJ day -1 ). Energy and fluid turnover were greatest on match days, followed by training and rest days, with no difference across weeks. This study provides criterion-assessed energy and fluid requirements to inform dietary guidance for female netball players., (© 2024 The Author(s). European Journal of Sport Science published by Wiley‐VCH GmbH on behalf of European College of Sport Science.)

Objective: This study investigated whether exposure to suboptimal gestational factors (SGFs) alters mechanical efficiency (ME) and substrate oxidation during rest and exercise in children as a mechanism contributing to obesity., Methods: Data from the Quebec Adiposity and Lifestyle Investigation in Youth cohort were used. Children aged 8 to 10 years performed an incremental maximal cycling test with indirect calorimetry. Their ME was measured during submaximal and maximal effort. The substrate oxidation during rest and submaximal effort was also computed. ME and substrate oxidation results between children exposed to each SGF during pregnancy (gestational diabetes mellitus: n = 68; hypertensive disorders: n = 49; maternal smoking: n = 77) and nonexposed children (n = 370) were compared., Results: No difference was observed for ME during submaximal (F [3,540]  = 0.46, p = 0.713) and maximal effort (F [3,545]  = 0.86, p = 0.463) between exposed and nonexposed children. The percentage contributions of lipids and carbohydrates did not differ during rest (F [3,545] =1.68, p = 0.169) or submaximal exercise (F [3,544]  = 0.31, p = 0.534) between exposed and nonexposed children., Conclusions: Children exposed to investigated SGFs display a similar physiological response regarding ME and substrate oxidation during rest and exercise compared to nonexposed children. Future studies should confirm these novel results and continue investigating other research avenues to explain the higher risk of obesity in this population., (© 2024 The Obesity Society.)

Background/objectives: Type 1 diabetes (T1D) is associated with an increase in resting metabolic rate (RMR), but the impact of T1D on other components of 24-h energy expenditure (24-h EE) is not known. Also, there is a lack of equations to estimate 24-h EE in patients with T1D. The aims of this analysis were to compare 24-h EE and its components in young adults with T1D and healthy controls across the spectrum of body mass index (BMI) and derive T1D-specific equations from clinical variables., Subjects/methods: Thirty-three young adults with T1D diagnosed ≥1 year prior and 33 healthy controls matched for sex, age and BMI were included in this analysis. We measured 24-h EE inside a whole room indirect calorimeter (WRIC) and body composition with dual x-ray absorptiometry., Results: Participants with T1D had significantly higher 24-h EE than healthy controls (T1D = 2047 ± 23 kcal/day vs control= 1908 ± 23 kcal/day; P < 0.01). We derived equations to estimate 24-h EE with both body composition (fat free mass + fat mass) and anthropometric (weight + height) models, which provided high coefficients of determination (R 2  = 0.912 for both). A clinical model that did not incorporate spontaneous physical activity yielded high coefficients of determination as well (R 2  = 0.897 and R 2  = 0.880 for body composition and anthropometric models, respectively)., Conclusion: These results confirm that young adults with established T1D have increased 24-h EE relative to controls without T1D. The derived equations from clinically available variables can assist clinicians with energy prescriptions for weight management in patients with T1D., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Humans require energy to sustain their daily activities throughout their lives. This narrative review aims to ( a ) summarize principles and methods for studying human energy expenditure, ( b ) discuss the main determinants of energy expenditure, and ( c ) discuss the changes in energy expenditure throughout the human life course. Total daily energy expenditure is mainly composed of resting energy expenditure, physical activity energy expenditure, and the thermic effect of food. Total daily energy expenditure and its components are estimated using variations of the indirect calorimetry method. The relative contributions of organs and tissues determine the energy expenditure under different physiological conditions. Evidence shows that energy expenditure varies along the human life course, at least in part due to changes in body composition, the mass and specific metabolic rates of organs and tissues, and levels of physical activity. This information is crucial to estimate human energy requirements for maintaining health throughout the life course.

Study Question: Is resting energy expenditure (REE) altered in women with polycystic ovary syndrome (PCOS)?, Summary Answer: Women with PCOS have a reduction in REE, when corrected for fat-free mass, independent of PCOS clinical phenotypes and BMI categories., What Is Known Already: Obesity is an important issue in women with PCOS, in terms of frequency and pathophysiological implications. It has been hypothesized that obesity may be favoured by alterations in REE, but the studies have been limited and conflicting., Study Design, Size, Duration: This case-control study was a comparison of 266 women with PCOS and 51 healthy controls, recruited in the Verona 3P study from 2010 to 2021., Participants/materials, Setting, Methods: Women with PCOS diagnosed by the Rotterdam criteria, with normal thyroid function and no interfering medications, were referred to the outpatient clinic of a tertiary care centre of endocrinology and metabolism for a measurement of REE. Healthy controls were recruited in the same period and submitted to the same procedure. In all subjects, REE was measured by indirect calorimetry and serum androgens were measured by LC-MS/MS. In women with PCOS, insulin sensitivity was assessed using the hyperinsulinemic-euglycemic clamp., Main Results and the Role of Chance: REE was similar in women with PCOS and controls. However, REE corrected for fat-free mass (REE/FFM) was significantly lower in women with PCOS than in controls (31.8 ± 4.0 vs 35.4 ± 3.9 kcal/kgFFM·day, P < 0.001). REE/FFM did not differ between normal-weight, overweight, or obese women with PCOS, and each of these subgroups showed lower REE/FFM values than controls. Reduced REE/FFM values were found in each phenotype of the syndrome. In multiple regression analysis, REE/FFM was independently associated with age and PCOS status, but not with fat mass. In PCOS women, REE/FFM was independently and directly associated with ovarian follicle number., Limitations, Reasons for Caution: Limitations of the study are the cross-sectional design, which limits the causal inference of the results, and the unavailability of precise information about lifestyle factors, which may be potential confounders. Further prospective studies are needed to establish the importance of this phenomenon in contributing to the weight excess of PCOS., Wider Implications of the Findings: A reduction of REE could potentially favour weight gain in women with PCOS and possibly contribute to the altered metabolic profile typical of this condition, even counteracting the therapeutic strategies aimed to reduce excess body fat in these women. Nevertheless, the presence of this abnormality in both obese/overweight and normal-weight patients suggests that other factors must play a role in this phenomenon., Study Funding/competing Interest(s): This work was supported by academic grants to PM from the University of Verona (FUR 2010-2022). All authors declare no conflict of interest., Trial Registration Number: N/A., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background and Objectives: A sustained mismatch between energy intake (EI) and exercise energy expenditure (EEE) can lead to Low Energy Availability (LEA), as well as health and performance impairments characteristic of Relative Energy Deficiency in Sport (RED-S). Research in females has identified specific LEA cut-points for the risks of developing physiological and performance disturbances. Cut-points in males have yet to be evaluated; therefore, this study examined the prevalence of LEA in highly trained male cross-country skiers. The key purpose of this study was to analyze EI, resting energy expenditure (REE), EEE, and energy availability (EA) in highly trained cross-country skiers during the preparation and competition periods. The secondary objective of our study was to evaluate the relative contribution of fats and carbohydrates to EI, REE, and EEE., Materials and Methods: EI was determined by an estimated 24 h diet recall method, REE was assessed by indirect calorimetry, and EEE was estimated from heart rate in 27 cross-country skiers., Results: EI amounted to 4050 ± 797 kcal/day on a typical training day (TD) and 5986 ± 924 kcal/day ( p < 0.001) on a typical competition day (CD). REE on TDs (2111 ± 294 kcal/day or 30 ± 6 kcal/day/kg) was higher ( p < 0.05) than on CDs (1891 ± 504 kcal/day or 27 ± 7 kcal/day/kg). The EA in the athletes was <15 kcal∙kg FFM -1 ·d -1 on TDs and <65 kcal∙kg FFM -1 ·d -1 on CDs. EI was not optimal, as indicated by low EA throughout TDs (June). This could be associated with insufficient EI along with a high amount of EEE (3690.7 ± 485.2 kcal/day). During the transition from TD to CD, an increase in the contribution of fats to EI and EEE was observed in cross-country skiers., Conclusion: The conception of LEA and REDs and their potential implication for performance is underestimated among coaches and athletes. The importance of appropriate dietary strategies is essential to ensure that enough calories are consumed to support efficient training.

This study aimed to investigate the resting metabolic rate (RMR) in cross-training practitioners (advanced and novice) using indirect calorimetry (IC) and compare it with predictive equations proposed in the scientific literature., Methods: A cross-sectional and comparative study analyzed 65 volunteers, both sexes, practicing cross-training (CT). Anthropometry and body composition were assessed, and RMR was measured by IC (FitMate PRO ® ), bioimpedance (BIA-InBody 570 ® ), and six predictive equations. Data normality was tested by the Kolgomorov-Smirnov test and expressed as mean ± standard deviation with 95% confidence intervals (CI), chi-square test was performed to verify ergogenic resources, and a Bland-Altman plot (B&A) was made to quantify the agreement between two quantitative measurements. One-way ANOVA was applied to body composition parameters, two-way ANOVA with Bonferroni post hoc was used to compare the RMR between groups, and two-way ANCOVA was used to analyze the adjusted RMR for body and skeletal muscle mass. The effect size was determined using Cohen's d considering the values adjusted by ANCOVA. If a statistical difference was found, post hoc Bonferroni was applied. The significance level was p < 0.05 for all tests., Results: The main results indicated that men showed a higher RMR than women, and the most discrepant equations were Cunningham, Tinsley (b), and Johnstone compared to IC. Tinsley's (a) equation indicated greater precision in measuring the RMR in CM overestimated it by only 1.9%, and BIA and the Harris-Benedict in CW overestimated RMR by only 0.1% and 3.4%, respectively., Conclusions: The BIA and Harris-Benedict equation could be used reliably to measure the RMR of females, while Tinsley (a) is the most reliable method to measure the RMR of males when measuring with IC is unavailable. By knowing which RMR equations are closest to the gold standard, these professionals can prescribe a more assertive diet, training, or ergogenic resources. An assertive prescription increases performance and can reduce possible deleterious effects, maximizing physical sports performance.

Prader-Willi syndrome (PWS) is a rare disorder characterised by varying nutritional phases that occur throughout the lifespan, ranging from failure to thrive to hyperphagia. If uncontrolled, the imbalance between energy intake and expenditure results in obesity development and increased morbidity and mortality risk. Although measures of energy requirements for accurate nutrition assessment are vital, the evidence appears sparse and heterogeneous; hence, the aim of this review was to examine the available literature on energy expenditure predicted or measured using various methods in individuals with PWS. Studies were sought that presented methods and results on resting energy expenditure or basal metabolic rate. A narrative synthesis was completed to present the study characteristics and results. Methods of determining energy requirements included predictive equations and indirect calorimetry. Differences amongst ages, growth hormone therapy, fasting status, and measures in which results were presented were limitations to appropriately summarising and identifying trends in energy expenditure. Indirect calorimetry was identified as the most accurate method; however, it is not widely available in all settings. Further research is encouraged to support the development of valid and reliable predictive equations that will better inform and improve the efficiency of clinical practice in supporting people with PWS.

The progression of Duchenne muscular dystrophy (DMD)requires the assessment of nutritional disturbances at each stage of the disease. The purpose of this study was to assess the nutritional status in various ages of boys with DMD using screening and in-depth evaluation methods. Body composition by Dual X-ray Absorptiometry (DXA), basal metabolic rate (BMR) by indirect calorimetry, a questionnaire of nutritional status-Pediatric Nutrition Screening Tool (PNST)-and laboratory parameters were performed. In the cohort of 93 boys aged 8.54 (5.9-12.6 years), inappropriate nutritional status occurred in 41.8% of boys (underweight 11.8%, overweight 16.0%, and obesity 14.0%). In the 10-13 age group, the occurrence of overweight and underweight was the highest. Based on PNST, 15.1% of patients were at nutritional risk (≥2 points)-the most in the 14-17 age group (29%). A negative correlation was identified between PNST and z-scores of body weight, BMI, and FFMI (r Spearman = -0.49, -0.46, and -0.48, respectively; p < 0.05). There were no differences between BMR results from indirect calorimetry and calculations from the Schofield formula for any age group. In obese boys, the caloric requirement in indirect calorimetry was significantly lower than that indicated by the calculations according to the Schofield formula ( p < 0.028). Inappropriate nutritional status occurred in almost half of the children with DMD. The age group in which nutritional disorders were most frequently identified was 10-13 years old. PNST could be considered a tool for screening malnutrition after testing a larger group of DMD patients.

Background and Objectives: Resting energy expenditure (REE) assessments can help inform clinical treatment decisions in adolescents with elevated body mass index (BMI), but current equations are suboptimal for severe obesity. We developed a predictive REE equation for youth with severe obesity and obesity-related comorbidities and compared results to previously published predictive equations., Methods: Data from indirect calorimetry, clinical measures, and body composition per Dual x-ray absorptiometry (DXA) were collected from five sites. Data were randomly divided into development (N = 438) and validation (N = 118) cohorts. A predictive equation was developed using Elastic Net regression, using sex, race, ethnicity, weight, height, BMI percent of the 95th%ile (BMIp95), waist circumference, hip circumference, waist/hip ratio, age, Tanner stage, fat and fat-free mass. This equation was verified in the validation cohort and compared with 11 prior equations., Results: Data from the total cohort (n = 556, age 15 ± 1.7 years, 77% female, BMIp95 3.3 ± 0.94) were utilized. The best fit equation was REE = -2048 + 18.17 × (Height in cm) - 2.57 × (Weight in kg) + 7.88 × (BMIp95) + 189 × (1 = male, 0 = female), R 2  = 0.466, and mean bias of 23 kcal/day., Conclusion: This new equation provides an updated REE prediction that accounts for severe obesity and metabolic complications frequently observed in contemporary youth., (© 2024 World Obesity Federation.)

Abstract Aims: To evaluate the nutritional status, resting energy expenditure, caloric and protein intake, and evolution of biochemical parameters in three stages of chronic kidney disease: pre-dialytic, at the beginning of the dialysis treatment, and 30 days after starting treatment. Methods: The chi-square and Student’s t tests were used to compare the variables, and analysis of repeated measurements was used to compare the data obtained in the three moments evaluated. The results were discussed at the 5% level of significance. Results: We evaluated 35 patients, 60% female and 60% with diabetes mellitus. There was a decrease in midarm circumference and serum albumin. Inflammatory state and caloric and protein intake increased. There was no significant difference in resting energy expenditure in the three moments. The serum urea and serum albumin, handgrip strength, and protein consumption after 30 days from the start of dialysis were greater in the peritoneal dialysis patients, when compared to the hemodialysis population. Conclusion: there was a decrease in midarm circumference and serum albumin and an increase in protein intake after dialysis. The peritoneal dialysis patients had higher muscle strength, even with lower protein intake. Resting energy expenditure was not different between dialysis methods and the moments evaluated.

The determination of energy requirements in clinical practice is based on basal metabolic rate (BMR), frequently predicted by equations that may not be suitable for individuals with severe obesity. This systematic review and meta-analysis examined the accuracy and precision of BMR prediction equations in adults with severe obesity. Four databases were searched in March 2021 and updated in May 2023. Eligible studies compared BMR prediction equations with BMR measured by indirect calorimetry. Forty studies (age: 28-55 years, BMI: 40.0-62.4 kg/m 2 ) were included, most of them with a high risk of bias. Studies reporting bias (difference between estimated and measured BMR) were included in the meta-analysis (n = 20). Six equations were meta-analyzed: Harris & Benedict (1919); WHO (weight) (1985); Owen (1986); Mifflin (1990); Bernstein (1983); and Cunningham (1980). The most accurate and precise equations in the overall analysis were WHO (-12.44 kcal/d; 95%CI: -81.4; 56.5 kcal/d) and Harris & Benedict (-18.9 kcal/d; 95%CI -73.2; 35.2 kcal/d). All the other equations tended to underestimate BMR. Harris & Benedict and WHO were the equations with higher accuracy and precision in predicting BMR in individuals with severe obesity. Additional analyses suggested that equations may perform differently according to obesity BMI ranges, which warrants further investigation., (© 2024 World Obesity Federation.)

The increasing preference for indoor exercise spaces highlights the relationship between indoor thermal environments and physiological responses, particularly concerning thermal comfort during physical activity. Determining the metabolic heat production rate during exercise is essential for optimizing the thermal comfort, well-being, and performance of individuals engaged in physical activities. This value can be determined during the activity using several methods, including direct calorimetry measurement, indirect calorimetry that uses analysis of respiratory gases, or approximations using collected data such as speed, body mass, and heart rate. The study aimed to calculate the metabolic heat production rate by infrared thermal evaluation (ITE) based on the body's thermal balance approach and compare it with the values determined by indirect calorimetry (IC). Fourteen participants volunteered for the study, using a cycling ergometer in a controlled climatic chamber. After the familiarization sessions, maximal O 2 intake levels (VO 2max ) were determined through maximal graded exercise tests. Subsequently, constant work rate exercise tests were performed at 60% of VO 2max for 20 min. The metabolic heat production rates were calculated by IC and ITE for each athlete individually. Respiratory gases were used to determine IC, while body skin and core temperatures, along with physical environmental data, were applied to calculate ITE using the human body thermal balance approximation of ASHRAE. According to the results, heat storage rates were misleading among the body's heat transfer modes, particularly during the first 8 min of the exercise. ITE showed a moderate level of correlation with IC (r: 0.03-0.86) with a higher level of dispersion relative to the mean (CV%: 12-84%). Therefore, a new equation (ITE new ) for the heat storage rates was proposed using the experimental data from this study. The results showed that ITE new provided more precise estimations for the entire exercise period (p > 0.05). Correlations between ITE new and IC values were consistently strong throughout the exercise period (r: 0.62-0.85). It can be suggested that ITE new values can predict IC during the constant work rate steady-state exercise., (© 2024. The Author(s) under exclusive licence to International Society of Biometeorology.)

Introduction: The US Army Load Carriage Decision Aid (LCDA) metabolic model is used by militaries across the globe and is intended to predict physiological responses, specifically metabolic costs, in a wide range of dismounted warfighter operations. However, the LCDA has yet to be adapted for vest-borne load carriage, which is commonplace in tactical populations, and differs in energetic costs to backpacking and other forms of load carriage., Purpose: The purpose of this study is to develop and validate a metabolic model term that accurately estimates the effect of weighted vest loads on standing and walking metabolic rate for military mission-planning and general applications., Methods: Twenty healthy, physically active military-age adults (4 women, 16 men; age, 26 ± 8 yr old; height, 1.74 ± 0.09 m; body mass, 81 ± 16 kg) walked for 6 to 21 min with four levels of weighted vest loading (0 to 66% body mass) at up to 11 treadmill speeds (0.45 to 1.97 m·s -1 ). Using indirect calorimetry measurements, we derived a new model term for estimating metabolic rate when carrying vest-borne loads. Model estimates were evaluated internally by k -fold cross-validation and externally against 12 reference datasets (264 total participants). We tested if the 90% confidence interval of the mean paired difference was within equivalence limits equal to 10% of the measured walking metabolic rate. Estimation accuracy, precision, and level of agreement were also evaluated by the bias, standard deviation of paired differences, and concordance correlation coefficient (CCC), respectively., Results: Metabolic rate estimates using the new weighted vest term were statistically equivalent ( P < 0.01) to measured values in the current study (bias, -0.01 ± 0.54 W·kg -1 ; CCC, 0.973) as well as from the 12 reference datasets (bias, -0.16 ± 0.59 W·kg -1 ; CCC, 0.963)., Conclusions: The updated LCDA metabolic model calculates accurate predictions of metabolic rate when carrying heavy backpack and vest-borne loads. Tactical populations and recreational athletes that train with weighted vests can confidently use the simplified LCDA metabolic calculator provided as Supplemental Digital Content to estimate metabolic rates for work/rest guidance, training periodization, and nutritional interventions., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)

Metabolic rate has been used in thermophysiological models for predicting the thermal response of humans. However, only a few studies have investigated the association between an individual's trait-like thermal sensitivity and resting energy expenditure (REE), which resulted in inconsistent results. This study aimed to explore the association between REE and perceived thermal sensitivity. The REE of healthy adults was measured using an indirect calorimeter, and perceived thermal intolerance and sensation in the body were evaluated using a self-administered questionnaire. In total, 1567 individuals were included in the analysis (women = 68.9%, age = 41.1 ± 13.2 years, body mass index = 23.3 ± 3.3 kg/m2, REE = 1532.1 ± 362.4 kcal/d). More women had high cold intolerance (31.8%) than men (12.7%), and more men had high heat intolerance (23.6%) than women (16.1%). In contrast, more women experienced both cold (53.8%) and heat (40.6%) sensations in the body than men (cold, 29.1%; heat, 27.9%). After adjusting for age, fat-free mass, and fat mass, lower cold intolerance, higher heat intolerance, and heat sensation were associated with increased REE only in men (cold intolerance, P for trend = .001; heat intolerance, P for trend = .037; heat sensation, P = .046), whereas cold sensation was associated with decreased REE only in women (P = .023). These findings suggest a link between the perceived thermal sensitivity and REE levels in healthy individuals., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The utility of using indirect calorimetry (IC) to estimate energy needs and methods for its application to this purpose remain unclear. This systematic review investigated whether using IC to estimate energy expenditure in critically ill patients is more meaningful for improving survival than other estimation methods., Methods: Comprehensive searches were conducted in MEDLINE using PubMed, Cochrane Central Register of Controlled Trials, and Igaku-Chuo-Zasshi up to March 2023., Results: Nine RCTs involving 1178 patients were included in the meta-analysis. The evidence obtained suggested that energy delivery by IC improved short-term mortality (risk ratio, 0.86; 95% confidence interval [CI], 0.70 to 1.06). However, the use of IC did not appear to affect the length of ICU stay (mean difference [MD], 0.86; 95% CI, -0.98 to 2.70) or the duration of mechanical ventilation (MD, 0.66; 95% CI, -0.39 to 1.72). Post hoc analyses using short-term mortality as the outcome found no significant difference by target calories in resting energy expenditure, whereas more frequent IC estimates were associated with lower short-term mortality and were more effective in mechanically ventilated patients., Conclusions: This updated meta-analysis revealed that the use of IC may improve short-term mortality in patients with critical illness and did not increase adverse events.

Background: Predicting energy requirements for older adults is compromised by the underpinning data being extrapolated from younger adults., Objectives: To generate and validate new total energy expenditure (TEE) predictive equations specifically for older adults using readily available measures (age, weight, height) and to generate and test new physical activity level (PAL) values derived from 1) reference method of indirect calorimetry and 2) predictive equations in adults aged ≥65 y., Methods: TEE derived from "gold standard" methods from n = 1657 (n = 1019 females, age range 65-90 y), was used to generate PAL values. PAL ranged 1.28-2.05 for males and 1.26-2.06 for females. Physical activity (PA) coefficients were also estimated and categorized (inactive to very active) from population means. Nonlinear regression was used to develop prediction equations for estimating TEE. Double cross-validation in a randomized, sex-stratified, age-matched 50:50 split, and leave one out cross-validation were performed. Comparisons were made with existing equations., Results: Equations predicting TEE using the Institute of Medicine method are as follows: For males, TEE = -5680.17 - 17.50 × age (years) + PA coefficient × (6.96 × weight [kilograms] + 44.21 × height [centimeters]) + 1.13 × resting metabolic rate (RMR) (kilojoule/day). For females, TEE = -5290.72 - 8.38 × age (years) + PA coefficient × (9.77 × weight [kilograms] + 41.51 × height [centimeters]) + 1.05 × RMR (kilojoule/day), where PA coefficient values range from 1 (inactive) to 1.51 (highly active) in males and 1 to 1.44 in females respectively. Predictive performance for TEE from anthropometric variables and population mean PA was moderate with limits of agreement approximately ±30%. This improved to ±20% if PA was adjusted for activity category (inactive, low active, active, and very active). Where RMR was included as a predictor variable, the performance improved further to ±10% with a median absolute prediction error of approximately 4%., Conclusions: These new TEE prediction equations require only simple anthropometric data and are accurate and reproducible at a group level while performing better than existing equations. Substantial individual variability in PAL in older adults is the major source of variation when applied at an individual level., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: 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., Methods: 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., Results: 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])., Conclusion: Implementation of a higher-protein formula protocol to patients with COVID-19 modestly reduced volume administration without impacting protein and energy delivery., (© 2024 The Authors. Journal of Parenteral and Enteral Nutrition published by Wiley Periodicals LLC on behalf of American Society for Parenteral and Enteral Nutrition.)

Objective: This report aimed to describe the results of total daily energy expenditure (TDEE) assessed by doubly labeled water ( DLW TDEE) and the adequacy of the dietary reference intakes (DRI) equations to estimate energy requirements ( DRI ER)., Methods: A cross-sectional and observational study in a convenience sample of 40 healthy Brazilian adults (≥20 years; 21 women) living in a tropical urban region. Basal metabolic rate (BMR) was measured by indirect calorimetry, DLW TDEE was compared with DRI ER using individual calculated physical activity level (PAL =  DLW TDEE/BMR) in its estimation., Results: BMR (5043 ± 548 kJ/day in women and 6213 ± 656 kJ/day in men), DLW TDEE (8372 ± 1324 kJ/day and 11 453 ± 1834 kJ/day), and PAL (1.66 ± 0.17 and 1.85 ± 0.30, respectively) were significantly higher in men. The DRI ER significantly overestimated DLW TDEE by 13.7 ± 8.3% and 12.7 ± 10.7% in women and men, respectively., Conclusion: In the present sample of relatively active urban Brazilian subjects, the DRI ER yielded inaccurate estimation of DLW TDEE. More data from low- and moderate-income countries are necessary to develop accurate estimates of TDEE., (© 2023 Wiley Periodicals LLC.)

Background: Many equations to estimate the resting energy expenditure (REE) of patients with burns are currently available, but which of them provides the best guide to optimize nutrition support is controversial. This review examined the bias and precision of commonly used equations in patients with severe burns., Methods: A systematic search of the PubMed, Web of Science, Embase, and Cochrane Library databases was undertaken on June 1, 2023, to identify studies comparing predicted REE (using equations) with measured REE (by indirect calorimetry [IC]) in adults with severe burns. Meta-analyses of bias and calculations of precisions were performed in each predictive equation, respectively., Results: Nine eligible studies and 12 eligible equations were included. Among the equations, the Toronto equation had the lowest bias (26.1 kcal/day; 95% CI, -417.0 to 469.2), followed by the Harris-Benedict equation × 1.5 (1.5HB) and the Milner equation. The Ireton-Jones equation (303.4 kcal/day; 95% CI, 224.5-382.3) acceptably overestimated the REE. The accuracy of all of the equations was <50%. The Ireton-Jones equation had the relatively highest precision (41.2%), followed by the 1.5HB equation (37.0%) and the Toronto equation (34.7%)., Conclusion: For adult patients with severe burns, all of the commonly used equations for the prediction of REE are inaccurate. It is recommended to use IC for accurate REE measurements and to use the Toronto equation, 1.5HB equation, or Ireton-Jones equation as a reference when IC is not available. Further studies are needed to propose more accurate REE predictive models., (© 2024 The Authors. Journal of Parenteral and Enteral Nutrition published by Wiley Periodicals LLC on behalf of American Society for Parenteral and Enteral Nutrition.)

Background: 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., Methods: 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., Results: 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/m 2 ; 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., Conclusion: 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., (© 2024 American Society for Parenteral and Enteral Nutrition.)

Objectives: Using equations to predict resting metabolic rate (RMR) has yielded different degrees of validity, particularly when sex and different physical activity levels were considered. Therefore, the purpose of the present study was to determine the validity of several different predictive equations to estimate RMR in female and male adults with varying physical activity levels., Method: We measured the RMR of 50 adults (26 females and 24 males) evenly distributed through activity levels varying from sedentary to ultra-endurance. Body composition was measured by dual X-ray absorptiometry and physical activity was monitored by accelerometry. Ten equations to predict RMR were applied (using Body Mass [BM]: Harris & Benedict, 1919; Mifflin et al., 1990 [Mifflin BM ]; Pontzer et al., 2021 [Pontzer BM ]; Schofield, 1985; FAO/WHO/UNU, 2004; and using Fat-Free Mass (FFM): Cunningham, 1991; Johnstone et al., 2006; Mifflin et al., 1990 [Mifflin FFM ]; Nelson et al. 1992; Pontzer et al., 2021 [Pontzer FFM ]). The accuracy of these equations was analyzed, and the effect of sex and physical activity was evaluated using different accuracy metrics., Results: Equations using BM were less accurate for females, and their accuracy was influenced by physical activity and body composition. FFM equations were slightly less accurate for males but there was no obvious effect of physical activity or other sample parameters. Pontzer FFM provides higher accuracy than other models independent of the magnitude of RMR, sex, activity levels, and sample characteristics., Conclusion: Equations using FFM were more accurate than BM equations in our sample. Future studies are needed to test the accuracy of RMR prediction equations in diverse samples., (© 2023 The Authors. American Journal of Human Biology published by Wiley Periodicals LLC.)

Background/objectives: Resting energy expenditure (REE) constitutes the largest component of total energy expenditure and undergoes an age-related decline that is unexplained by decreased fat-free mass. Phase angle (PhA) is a cellular health indicator that is possibly associated with REE. We investigated the association of REE and PhA in hospitalized older adults., Subjects/methods: This single-center, cross-sectional analysis utilized the baseline data from a prospective longitudinal study and included 131 eligible patients aged ≥70 years. The REE was measured using indirect calorimetry, and PhA and body composition were assessed using bioelectrical impedance. The association between REE, PhA, and body composition was examined, and REE was compared using previously reported PhA cutoff values., Results: In this cohort with a mean (±standard deviation) age of 87.4 (±7.0) years, 34.4% of the participants were men. REE and PhA correlated strongly (r: 0.562, p < 0.001) and significantly after adjusting for age and sex (r: 0.433, p < 0.001). Multivariate analysis showed a significant independent association between REE and PhA and skeletal muscle mass (standardized β [95% CI]; 28.072 [2.188-53.956], p = 0.035) without any significant interaction between PhA and age on REE. The low PhA group had a significantly lower REE (kcal/day; 890 [856-925] vs. 1077 [1033-1122], p < 0.001), and this remained significant after adjusting for age, sex, and skeletal muscle mass index., Conclusions: PhA is associated with REE in older adults. Adjusting REE calculation algorithms based on PhA values and correcting predicted REE according to PhA may aid in determining more accurate energy requirements., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Purpose: Caffeine is a stimulant with well-recognized performance and metabolic benefits, however, there is a lack of studies investigating the time-of-day influence in the properties of caffeine to enhance fat oxidation in women. Thus, the aim of the present study was to evaluate the influence of the time of the day on the effect of caffeine on the maximal rate of fat oxidation during aerobic exercise in trained women., Methods: Fourteen female athletes (25.5 ± 7.1 years) took part in a randomized, crossover, double-blind study. All participants undertook four different experimental trials combining the ingestion of 3 mg/kg caffeine and a placebo either in the morning (8.00-10.00 h) and in the evening (17.00-19.00 h) realizing an incremental test on a cycle ergometer with 3 min stages at workloads from 30 to 70% of maximal oxygen uptake (VO 2max ). Substrate oxidation rates were measured by indirect calorimetry. In each trial, the maximum rate of fat oxidation (MFO) and the intensity that elicited MFO (Fatmax) were measured., Results: In comparison to placebo, MFO was significantly higher with caffeine both in the morning (0.24 ± 0.13 vs 0.30 ± 0.14 g/min; p < 0.001; ES = 0.79) and in the evening (0.21 ± 0.08 vs 0.28 ± 0.10 g/min; p = 0.002; ES = 0.72). No time-of-day effect on the capacity of caffeine to increase MFO was found (all p = 0.336) CONCLUSION: The intake of 3 mg/kg of caffeine increased the use of fat as a fuel during exercise independently of the time-of-day in trained women., Trial Registration: The study was registered in ClinicalTrials.gov with the following ID: NCT05880186 by 15 May 2023., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Albeit being a major determinant of exercise-related energy expenditure (EE), there is a lack of research on the excess post-exercise oxygen consumption (EPOC) after different exercise modalities in older adults. This study compared the EPOC after isocaloric bouts of resistance (RE) and aerobic (AE) exercise. Methods: The EE during exercise was determined through telemetric indirect calorimetry in ten physically active participants aged 63 to 82 years (5 women, 73 ± 6 years, 70.5 ± 9.9 kg, 161 ± 8 cm). The target EE in AE corresponded to values achieved during RE, and the EPOC was assessed for 30 min in the supine position. Results: The EE during AE and RE were 126.0 ± 30.7 kcal and 123.9 ± 30.6 kcal, respectively. The time to achieve the target EE was 2.3 times shorter in AE vs . RE. The EPOC magnitude was greater after AE (7.9 ± 2.4 L, 40.1 ± 11.1 kcal) than RE (5.9 ± 1.8 L, 26.9 ± 11.5 kcal). Conclusion: Older adults showed greater EPOC after isocaloric sessions of AE vs . RE. Additionally, AE had better temporal efficiency than RE to elicit a given EE.

We propose a novel method for assessing metabolic flexibility (MF) through indirect calorimetry. A total of twenty healthy volunteers (10 females; 10 males) aged 45-65 were categorized into a Low-Intensity activity group (LI, 0-1 session of 1 h per week) and a High-Intensity activity group (HI, 5-6 sessions of 2 h per week). Volunteers underwent a stepwise exercise test on a cycle ergometer, connected to a calorimeter, to examine respiratory gas exchange to evaluate peak fatty acid Oxidation (PFO) and peak carbohydrate oxidation (PCO). Circulating peroxisome proliferator-activated receptor α (PPARα) biomarkers, docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio and N -oleoylethanolamine (OEA), and the endocannabinoid- 2-arachidonoylglycerol (2-AG), were evaluated. We developed two MF parameters: the MF index (MFI), calculated by the product of PFO normalized per kg of fat-free mass (FFM) and the percentage of VO 2max at PFO, and the peak energy substrates' oxidation (PESO), computed by summing the kilocalories from the PFO and PCO, normalized per kg FFM. The MFI and PESO were significantly different between the HI and LI groups, showing strong correlations with the circulating bioactive substances. Higher DHA/EPA ratio ( p ≤ 0.05) and OEA ( p ≤ 0.01), but lower 2-AG levels ( p ≤ 0.01) were found in the HI group. These new parameters successfully established a functional link between MF and the balance of PPARα/endocannabinoid systems.

Objectives: Patients undergoing hematopoietic stem cell transplantation may present with metabolic alterations that can have an effect on their energy expenditure and nutritional status. This project aimed to compare the pre- and posttransplant energy expenditures of patients undergoing hematopoietic stem cell transplantation as well as related factors., Methods: This prospective study was conducted at a single center. Patients, undergoing autograft or allograft, were evaluated before transplantation and on the 10th and 17th d posttransplantation. Energy expenditure was measured by indirect calorimetry. Diet intake was assessed by a 24-h dietary recall. Infectious and noninfectious complications were analyzed between days 1 to 10 after transplantation and days 11 to 17 after transplantation. Paired model analyses were carried out to identify the pretransplantation and posttransplantation periods., Results: Twenty patients were evaluated with a mean age of 45.6 ± 17.2 y; a majority were male sex (65%), and the most frequent diagnoses were chronic myeloid leukemia (25%) and multiple myeloma (25%). Energy expenditure increased by 15% posttransplantation, and the energy requirement per kilogram of weight was 23 kcal/kg at day 10 after transplantation. Throughout the posttransplantation period, 45% of the patients required nutritional therapy. Negative energy and negative protein balance were observed at all analyzed times. Phase angle (P = 0.018), fever (P = 0.014), mucositis grades I to II (P = 0.018), and the total number of infectious and noninfectious events (P = 0.043) were associated with an increase in energy expenditure at day 10 after transplantation., Conclusions: Energy expenditure increased after transplantation compared with pretransplantation in 50% of patients. Phase angle, fever, grades I to II mucositis, and infectious and noninfectious events were associated with increased energy expenditure at day 10 after transplantation., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses or interpretation of data, in the writing of the manuscript, or in the decision to publish the results., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background & Aims: Weight reduction programs in people with overweight or obesity can be informed by indirect calorimetry (IC) which is the gold standard to measure basal metabolic rate (BMR). Since IC is labor intensive and expensive, predictive equations are often used as an alternative. In this study the accuracy rate was assessed and bias statistics of predictive equations were compared to IC among subjects with overweight or obesity. Secondly, differences in clinical features between individuals with over-, accurate or underestimation of their BMR were evaluated., Methods: This cross sectional study included 731 subjects from the outpatient obesity clinic of the Antwerp University Hospital, Belgium. Fourteen equations were evaluated. Overestimation and underestimation was defined as >10 % and <10 % of measured BMR., Results: In the total population, mean age was 43 ± 13 years, mean BMI 35.6 ± 5.8 kg/m 2 and 79.5 % were female. The highest accuracy rates were reached by the Henry (73 %), Ravussin (73 %) and Mifflin St. Jeor (73 %) equations. In the total population, the Mifflin St. Jeor and Henry equation were unbiased. The Akern, Livingston and Ravussin equations were biased to underestimation. All other equations were biased to overestimation. Subjects with an underestimation of BMR had significantly higher waist-hip ratio (1.02 ± 0.13 vs 0.91 ± 0.11; P < 0.001), higher visceral adipose tissue (239 ± 96 vs 162 ± 93; P < 0.001), lower fat free mass (kg) (67.6 (45.4-95.9) vs 54.0 (39.6-95.5); P < 0.001) and a higher prevalence of the Metabolic Syndrome (24 (77.4) vs 112 (37.5); P < 0.001). Individuals with an overestimation of BMR had significantly higher subcutaneous adipose tissue (545 ± 149 vs 612 ± 149; P < 0.05), lower fasting plasma insulin (81 (10-2019) vs 67 (27-253); P < 0.001) and lower 2-h plasma glucose (132 (30-430) vs 116 (43-193); P < 0.001) during OGTT., Conclusions: In this study, the Henry and Mifflin St. Jeor equations have the highest accuracy and lowest bias to estimate the basal metabolic rate in a Caucasian, predominantly female, population living with overweight or obesity. Visceral and subcutaneous adipose tissue and presence of metabolic syndrome were significantly different in individuals with over- or underestimation of BMR., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

A traumatic brain injury (TBI) is one of the most common pediatric traumas among children in the United States. Appropriate nutrition support, including the initiation of early enteral nutrition, within the first 48 h after injury is crucial for children with a TBI. It is important that clinicians avoid both underfeeding and overfeeding, as both can lead to poor outcomes. However, the variable metabolic response to a TBI can make determining appropriate nutrition support difficult. Because of the dynamic metabolic demand, indirect calorimetry (IC) is recommended, instead of predictive equations, to measure energy requirements. Although IC is suggested and ideal, few hospitals have the technology available. This case review discusses the variable metabolic response, identified using IC, in a child with a severe TBI. The case report highlights the ability of the team to meet measured energy requirements early, even in the setting of fluid overload. It also highlights the presumed positive impact of early and appropriate nutrition provision on the patient's clinical and functional recovery. Further research is needed to investigate the metabolic response to TBIs in children and the impact optimal feedings based on the measured resting energy expenditure have on clinical, functional, and rehabilitation outcomes., (© 2023 The Authors. Nutrition in Clinical Practice published by Wiley Periodicals LLC on behalf of American Society for Parenteral and Enteral Nutrition.)

Background: Patients experiencing persistent critical illness have poor short-term and long-term outcomes and consume disproportionate amounts of health care resources. Nutrition optimization may improve outcomes, though few data exist on resting energy expenditure and nutrition requirements. We hypothesized that increased energy surplus per day is associated with increased intensive care unit (ICU) length of stay (LoS) in critically ill patients., Methods: Patients from a single ICU at Royal London Hospital were included in this retrospective cohort study., Exposure: energy surplus measured by serial indirect calorimetry (IC) and nutrition intake., Inclusion Criteria: mechanical ventilation of ≥3 days and expected to remain ventilated., Primary Outcome: ICU LoS., Results: Across 30 patients (median LoS 21 days), increased ICU LoS was associated with actual daily energy intake surplus to resting energy expenditure (REE) (R 2 0.16; P < 0.005). Median REE was less than predicted energy requirements: 24 kcal per day per kilogram of ideal body weight (IBW) (interquartile range [IQR], 20-28) vs 28 kcal/day/kg IBW (IQR, 26-29) (P < 0.001). Patients with COVID-19 had a median energy surplus (actual intake- REE) + 344 kcal/day (IQR 35-517) vs -57 kcal/day (IQR -324 to 211) in other patients (P = 0.011); however, they had a median LoS of 44 days (IQR 26-58) vs 10 days (IQR 7-24), respectively (P < 0.001). Patients with obesity had a median energy deficit of -32 kcal/day (IQR -384 to 335) vs +234 kcal/day (IQR -79 to 499) for nonobese patients (P = 0.021)., Conclusion: Overfeeding represents an easily modifiable factor to improve outcomes in patients experiencing persistent critical illness, for which IC may be useful., (© 2023 The Authors. Journal of Parenteral and Enteral Nutrition published by Wiley Periodicals LLC on behalf of American Society for Parenteral and Enteral Nutrition.)

Determining resting metabolic rate (RMR) is an important aspect when calculating energy requirements for professional rugby union players. Prediction equations are often used for convenience to estimate RMR. However, the accuracy of current prediction equations for professional rugby union players remains unclear. The aims of this study were to examine the RMR of professional male rugby union players compared to nine commonly used prediction equations and develop and validate RMR prediction equations specific to professional male rugby union players. One hundred and eight players (body mass (BM) = 102.9 ± 13.3 kg; fat-free mass (FFM) = 84.8 ± 10.2 kg) undertook Dual-energy X-ray Absorptiometry scans to assess body composition and indirect calorimetry to determine RMR. Mean RMR values of 2585 ± 176 kcal∙day -1 were observed among the group with forwards (2706 ± 94 kcal·day -1 ), demonstrating significantly ( p < 0.01; d = 1.93) higher RMR compared to backs (2465 ± 156 kcal·day -1 ), which appeared to be due to their higher BM and FFM measures. Compared to the measured RMR for the group, seven of the nine commonly used prediction equations significantly ( p < 0.05) under-estimated RMR (-104-346 kcal·day -1 ), and one equation significantly ( p < 0.01) over-estimated RMR (192 kcal·day -1 ). This led to the development of a new prediction equation using stepwise linear regression, which determined that the strongest predictor of RMR for this group was FFM alone ( R 2 = 0.70; SEE = 96.65), followed by BM alone ( R 2 = 0.65; SEE = 104.97). Measuring RMR within a group of professional male rugby union players is important, as current prediction equations may under- or over-estimate RMR. If direct measures of RMR cannot be obtained, we propose the newly developed prediction equations be used to estimate RMR within professional male rugby union players. Otherwise, developing team- and/or group-specific prediction equations is encouraged.

Background: The accurate assessment of resting energy expenditure (REE) is essential for personalized nutrition, particularly in critically ill children. Indirect calorimetry (IC) is the gold standard for measuring REE. This methodology is based on the measurement of oxygen consumption (VO 2 ) and carbon dioxide production (VCO 2 ). These parameters are integrated into the Weir equation to calculate REE. Additionally, IC facilitates the determination of the respiratory quotient (RQ), offering valuable insights into a patient's carbohydrate and lipid consumption. IC validation is limited to spontaneously breathing and mechanically ventilated patients, but it is not validated in patients undergoing non-invasive ventilation (NIV). This study investigates the application of IC during NIV-CPAP (continuous positive airway pressure) and NIV-PS (pressure support)., Methods: This study was conducted in the Pediatric Intensive Care Unit of IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, between 2019 and 2021. Children < 6 years weaning from NIV were enrolled. IC was performed during spontaneous breathing (SB), NIV-CPAP, and NIV-PS in each patient. A Bland-Altman analysis was employed to compare REE, VO 2 , VCO 2 , and RQ measured by IC., Results: Fourteen patients (median age 7 (4; 18) months, median weight 7.7 (5.5; 9.7) kg) were enrolled. The REE, VO 2 , VCO 2 , and RQ did not differ significantly between the groups. The Limits of Agreement (LoA) and bias of REE indicated good agreement between SB and NIV-CPAP (LoA +28.2, -19.4 kcal/kg/day; bias +4.4 kcal/kg/day), and between SB and NIV-PS (LoA -22.2, +23.1 kcal/kg/day; bias 0.4 kcal/kg/day)., Conclusions: These preliminary findings support the accuracy of IC in children undergoing NIV. Further validation in a larger cohort is warranted.

Objective: To study the severity of systemic metabolic dysfunction in various types of stroke and determine the parameters of optimal energy and protein supply for this category of patients in the presence of severe neurological deficit (National Institutes of Health Stroke Scale - NIHSS score of 15 points or more) during different periods of the disease., Material and Methods: The retrospective study included 512 patients with acute cerebrovascular accident (ACVA) who received nutritional support (NS) for 10 days or more: 367 (71.7%) people with ischemic stroke (IS) and 145 (28.3%) - with hemorrhagic stroke (HS). The course of stroke in all patients included in the study was accompanied by severe and extremely severe neurological disorders (15 points or more on the NIHSS scale). Energy expenditure and the severity of the catabolic reaction of the body were studied by dynamic assessment of indirect calorimetry indicators and actual nitrogen losses., Results: More than 99% of patients received tube feeding. Using the method of indirect calorimetry, the ranges of energy expenditure during stroke were determined: for IS - 1600-2100 kcal/day (24-26 kcal/kg/day), for HS - 1900-2600 kcal/day (26-30 kcal/kg/day) in depending on the period of the disease. The average nitrogen losses at all stages of the disease in patients with IS and HS were comparable. In IS, these amounts were 19 g/day (0.25 g/kg/day), which corresponds to 119 g/day of protein (1.56 g/kg/day of protein), and in HS patients lost an average of 18.9 g/day of nitrogen (0.24 g/kg/day) or 118 g/day of protein (1.5 g/kg/day of protein). The maximum nitrogen losses were observed in the period from 10 to 20 days of illness and amounted to 24.7 g/day in patients with HS (0.31 g/kg/day or 1.93 g/kg/day protein), and in patients with IS - 24.5 g/day (0.29 g/kg/day or 1.81 g/kg/day protein)., Conclusion: An identified trend towards a decrease in mortality in patients with acute stroke with energy supply in the amount of 27-28 kcal/kg/day and protein consumption in the amount of 1.3-1.4 g/kg/day compared with patients receiving 20-21 kcal/kg /day and 1-1.2 g/kg/day of protein requires further prospective randomized studies.