Total energy expenditure assessed by 24-h whole-room indirect calorimeter in patients with colorectal cancer: baseline findings from the PRIMe study.

BACKGROUND: Total energy expenditure (TEE) determines energy requirements, but objective data in patients with cancer are limited. OBJECTIVES: We aimed to characterize TEE, investigate its predictors, and compare TEE with cancer-specific predicted energy requirements. METHODS: This cross-sectional analysis included patients with stages II-IV colorectal cancer from the Protein Recommendation to Increase Muscle (PRIMe) trial. TEE was assessed by 24-h stay in a whole-room indirect calorimeter before dietary intervention and compared with cancer-specific predicted energy requirements (25-30 kcal/kg). Generalized linear models, paired-samples t tests, and Pearson correlation were applied. RESULTS: Thirty-one patients (56 ± 10 y; body mass index [BMI]: 27.9 ± 5.5 kg/m2; 68% male) were included. Absolute TEE was higher in males (mean difference: 391 kcal/d; 95% CI: 167, 616 kcal/d; P < 0.001), patients with colon cancer (mean difference: 279 kcal/d; 95% CI: 73, 485 kcal/d; P = 0.010), and patients with obesity (mean difference: 393 kcal/d; 95% CI: 182, 604 kcal/d; P < 0.001). Appendicular lean soft tissue (ß: 46.72; 95% CI: 34.27, 59.17; P < 0.001) and tumor location (colon-ß: 139.69; 95% CI: 19.44, 259.95; P = 0.023) independently predicted TEE when adjusted for sex. Error between measured TEE and energy requirements predicted by 25 kcal/kg (mean difference: 241 kcal/d; 95% CI: 76, 405 kcal/d; P = 0.010) or 30 kcal/kg (mean difference: 367 kcal/d; 95% CI: 163, 571 kcal/d; P < 0.001) was higher for patients with obesity, and proportional error was observed (25 kcal/kg: r = -0.587; P < 0.001; and 30 kcal/kg: r = -0.751; P < 0.001). TEE (mean difference: 25 kcal/kg; 95% CI: 24, 27 kcal/kg) was below predicted requirements using 30 kcal/kg (-430 ± 322 kcal/d; P < 0.001). CONCLUSIONS: This is the largest study to assess TEE of patients with cancer using whole-room indirect calorimeter and highlights the need for improved assessment of energy requirements in this population. Energy requirements predicted using 30 kcal/kg overestimated TEE by 1.44 times in a controlled sedentary environment and TEE was outside of the predicted requirement range for most. Special considerations are warranted when determining TEE of patients with colorectal cancer, such as BMI, body composition, and tumor location. This is a baseline cross-sectional analysis from a clinical trial registered at clinicaltrials.gov as NCT02788955 (https://clinicaltrials.gov/ct2/show/NCT02788955).

Elevated energy costs of biomass production in mitochondrial respiration-deficient Saccharomyces cerevisia.

Microbial growth requires energy for maintaining the existing cells and producing components for the new ones. Microbes therefore invest a considerable amount of their resources into proteins needed for energy harvesting. Growth in different environments is associated with different energy demands for growth of yeast Saccharomyces cerevisiae, although the cross-condition differences remain poorly characterized. Furthermore, a direct comparison of the energy costs for the biosynthesis of the new biomass across conditions is not feasible experimentally; computational models, on the contrary, allow comparing the optimal metabolic strategies and quantify the respective costs of energy and nutrients. Thus in this study, we used a resource allocation model of S. cerevisiae to compare the optimal metabolic strategies between different conditions. We found that S. cerevisiae with respiratory-impaired mitochondria required additional energetic investments for growth, while growth on amino acid-rich media was not affected. Amino acid supplementation in anaerobic conditions also was predicted to rescue the growth reduction in mitochondrial respiratory shuttle-deficient mutants of S. cerevisiae. Collectively, these results point to elevated costs of resolving the redox imbalance caused by de novo biosynthesis of amino acids in mitochondria. To sum up, our study provides an example of how resource allocation modeling can be used to address and suggest explanations to open questions in microbial physiology.

Body composition affects the accuracy of predictive equations to estimate resting energy expenditure in older adults: An exploratory study.

BACKGROUND: To investigate the accuracy of ten different predictive equations to estimate resting energy expenditure (REE) in a sample of Brazilian older adults and develop a predictive equation for estimating REE based on body composition data. METHODS: A cross-sectional study with thirty-eight Brazilian older adults aged 60-84 years, who had their REE measured by indirect calorimetry (IC) and BC assessed by dual-energy x-ray absorptiometry (DXA). REE was compared to the estimation of ten predictive equations, and the differences between BC and anthropometric-based equations were investigated using Bland-Altman plots and Lin's concordance correlation. Accuracy was evaluated considering ±10% of the ratio between estimated and measured REE. RESULTS: The sample was composed of 57.9% men, with a mean age of 68.1 (5.8) years, and a mean REE by IC of 1528 (451) kcal. The highest accuracy was 47.4% obtained by Luhrmann and Fredrix equations, and the lowest accuracy was 13.2% reached by Weigle equation. In general, the proportion of underestimation was higher than overestimation. All anthropometric-based equations presented a good agreement with REE from IC. For those equations derived from BC, however, three of them reached only a moderate agreement. In terms of accuracy, all equations presented lower than 50% of accurate prediction of REE. CONCLUSIONS: In this sample of older adults, previous predictive equations to estimate REE did not show good accuracy, and those based on BC presented even worse results, showing that changes in BC related to aging could impact the accuracy of these equations.

Nutritional Status and Other Clinical Variables Are Associated to the Resting Energy Expenditure in Patients With Chronic Kidney Disease: A Validity Study.

Background: Estimating energy requirements (ER) is crucial for nutritional attention to chronic kidney disease (CKD) patients. Current guidelines recommend measuring ER with indirect calorimetry (IC) when possible. Due to clinical settings, the use of simple formulas is preferred. Few studies have modeled equations for estimating ER for CKD. Nevertheless, variables of interest such as nutritional status and strength have not been explored in these models. This study aimed to develop and validate a model for estimating REE in patients with CKD stages 3-5, who were not receiving renal replacement therapy (RTT), using clinical variables and comparing it with indirect calorimetry as the gold standard. Methods: In this study 80 patients with CKD participated. Indirect calorimetry (IC) was performed in all patients. The calorimeter analyzed metabolic measurements every minute for 15 min after autocalibration with barometric pressure, temperature, and humidity. Bioelectrical Impedance Analysis (BIA) was performed. Fat-free mass (FFM) was registered among other bioelectrical components. Handgrip strength (HGS) was evaluated and an average of 3 repetitions was recorded. Nutritional status was assessed with the subjective global assessment (SGA). Patients categorized as B or C were then considered as having malnutrition. Results: We analyzed 71 patients and 3 models were generated. Model 1a included FFM; Model 2a included weight; Model 3c included handgrip strength (HGS). All other variables were stepwise, computer-selected with a p < 0.01 significance level; Malnutrition was consistently associated with ER among other clinical variables in all models (p < 0.05). The model that included BIA-FFM had R 2 adjusted = 0.46, while the model that included weight (Kg) had an adjusted R 2 adjusted = 0.44. The models had moderate concordance, LC = 0.60-0.65 with the gold standard, whereas other energy expenditure estimation equations had LC = 0.36 and 0.55 with indirect calorimetry. Using these previously validated equations as a reference, our models had concordance values ranging from 0.66 to 0.80 with them. Conclusion: Models incorporating nutritional status and other clinical variables such as weight, FFM, comorbidities, gender, and age have a moderate agreement with REE. The agreement between our models and others previously validated for the CKD patient is good; however, the agreement between the latter and IC measurements is moderate. The KDOQI lowest recommendation (25 Kcals/kg body weight) considering the 22% difference with respect to the IC for total energy expenditure rather than for REE.

Predicted estimates of resting energy expenditure have limited clinical utility in patients with cirrhosis.

BACKGROUND & AIMS: Malnutrition is associated with adverse clinical outcomes in patients with cirrhosis. Accurate assessment of energy requirements is needed to optimize dietary intake. Resting energy expenditure (REE), the major component of total energy expenditure, can be measured using indirect calorimetry (mREE) or estimated using prediction equations (pREE). This study assessed the usefulness of predicted estimates of REE in this patient population. METHODS: Individual mREE data were available for 900 patients with cirrhosis (mean [±1 SD] age 55.7±11.6 years-old; 70% men; 52% south-east Asian) and 282 healthy controls (mean age 36.0±12.8 years-old; 52% men; 18% south-east Asian). Metabolic status was classified using thresholds based on the mean ± 1 SD of the mREE in the healthy controls. Comparisons were made between mREE and pREE estimates obtained using the Harris-Benedict, Mifflin, Schofield and Henry equations. Stepwise regression was used to build 3 new prediction models which included sex, ethnicity, body composition measures, and model for end-stage liver disease scores. RESULTS: The mean mREE was significantly higher in patients than controls when referenced to dry body weight (22.4±3.8 cf. 20.8±2.6 kcal/kg/24 hr; p <0.001); there were no significant sex differences. The mean mREE was significantly higher in Caucasian than Asian patients (23.1±4.4 cf. 21.7±2.9 kcal/kg/24 hr; p <0.001). Overall, 37.1% of Caucasian and 25.3% of Asian patients were classified as hypermetabolic. The differences between mREE and pREE were both statistically and clinically relevant; in the total patient population, pREE estimates ranged from 501 kcal/24 hr less to 548 kcal/24 hr more than the mREE. Newly derived prediction equations provided better estimates of mREE but still had limited clinical utility. CONCLUSIONS: Prediction equations do not provide useful estimates of REE in patients with cirrhosis. REE should be directly measured. LAY SUMMARY: People with cirrhosis are often malnourished and this has a detrimental effect on outcome. Provision of an adequate diet is very important and is best achieved by measuring daily energy requirements and adjusting dietary intake accordingly. Prediction equations, which use information on age, sex, weight, and height can be used to estimate energy requirements; however, the results they provide are not accurate enough for clinical use, particularly as they vary according to sex and ethnicity.

Resting Energy Expenditure in the Elderly: Systematic Review and Comparison of Equations in an Experimental Population.

Elderly patients are at risk of malnutrition and need an appropriate assessment of energy requirements. Predictive equations are widely used to estimate resting energy expenditure (REE). In the study, we conducted a systematic review of REE predictive equations in the elderly population and compared them in an experimental population. Studies involving subjects older than 65 years of age that evaluated the performance of a predictive equation vs. a gold standard were included. The retrieved equations were then tested on a sample of 88 elderly subjects enrolled in an Italian nursing home to evaluate the agreement among the estimated REEs. The agreement was assessed using the intraclass correlation coefficient (ICC). A web application, equationer, was developed to calculate all the estimated REEs according to the available variables. The review identified 68 studies (210 different equations). The agreement among the equations in our sample was higher for equations with fewer parameters, especially those that included body weight, ICC = 0.75 (95% CI = 0.69-0.81). There is great heterogeneity among REE estimates. Such differences should be considered and evaluated when estimates are applied to particularly fragile populations since the results have the potential to impact the patient's overall clinical outcome.

Energy expenditure during pregnancy: a systematic review.

CONTEXT: Contrary to nutritional guidelines, accumulating evidence shows that pregnant women's energy intakes remain stable throughout trimesters. Although pregnant women may eat below their needs or underreport their energy intakes, it is also relevant to question how energy requirements - estimated through measurements of energy expenditure (EE) - change throughout pregnancy. OBJECTIVE: This review examined prospective studies that measured EE during pregnancy, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: PubMed/MEDLINE, Web of Science, Embase, and CINAHL databases were searched to identify relevant publications up to November 14, 2019. STUDY SELECTION: All studies that measured EE prospectively and objectively during pregnancy were included in this systematic review. Two authors independently screened 4852 references. A total of 32 studies were included in the final analysis. DATA EXTRACTION: One author extracted data and assessed the risk of bias and a second author did so for a random sample of studies (n = 7; 22%). DATA ANALYSIS: Increases in resting EE ranged from 0.5% to 18.3% (8-239 kcal), from 3.0% to 24.1% (45-327 kcal), and from 6.4% to 29.6% (93-416 kcal) between early and mid-, mid- and late, and early and late pregnancy, respectively. Increases in total EE ranged from 4.0% to 17.7% (84-363 kcal), from 0.2% to 30.2% (5-694 kcal), and from 7.9% to 33.2% (179-682 kcal) between early and mid-, mid- and late, and early and late pregnancy, respectively. Participants were mainly of normal weight, although many studies did not report important covariates such as prepregnancy body mass index and gestational weight gain adequacy. CONCLUSIONS: Additional high-quality longitudinal studies (ie, with multiple objective measurements of EE in all periods of pregnancy while considering important confounding variables, like gestational weight gain) are required.

Prediction of resting energy expenditure in healthy older adults: A systematic review.

BACKGROUND & AIMS: Estimates of energy requirements, based on measured or predicted resting energy expenditure (REE), are needed to avoid undernutrition or overnutrition (and their clinical consequences) in elderly subjects. The aims of this systematic review were to evaluate the prediction accuracy of REE in healthy elderly subjects and to ascertain which equation is more reliable at group level and/or individual level. METHODS: Studies assessing prediction of REE in general elderly population were systematically searched using PubMed, EMBASE, Web of Science and CINAHL until March 2020. Prediction accuracy of REE was assessed at both group (bias) and individual (precision) level for each equation. RESULTS: Fourteen studies met the inclusion criteria of this systematic review. Bias was reported in 8 papers and calculated in another 5 from absolute values. There was a prevalent tendency towards an overestimation of REE across the studies. The least bias was observed for the Mifflin (-0.3%) and Harris-Benedict (+2.6%) equations, with values above 5% for the FAO/WHO/UNU, Fredrix and Muller equations. Precision widely varied between studies for the same equation. The higher precision was observed using the Harris-Benedict equation (~70%), while the Henry and Mifflin equations provided estimates within 10% of measured values in 65% and 61% of elderly individuals, respectively. CONCLUSIONS: None of the prediction equations considered provides accurate and precise REE estimates in healthy older adults. However, the best prediction is given by the Mifflin equation at group level and by the Harris-Benedict equation at individual level. Further studies with strong quality design are needed to evaluate the variability and accuracy of REE in the elderly general population.

Claims of anomalously long fasting: An assessment of the evidence from investigated cases.

BACKGROUND: Throughout history and to the present day, there have been reports of people claiming inedia, i.e., an anomalous long-term abstinence from food or from food and fluid. Some were isolated and monitored and their abstinences confirmed. This raises the question of whether there may be an anomaly with wide implications that science has overlooked. On the other hand, there have been cases of exposed fraud. The reports on the studies are scattered and it can be difficult to judge their rigor and the strength and implications of their evidence. A critical evaluation seems useful. OBJECTIVES: The objectives were to obtain an overview of investigated cases of claimed inedia, to assess the anomaly of the claims and study results, to assess the quality of the studies, and to identify deception methods to inform future safeguards. METHOD: I developed criteria for differentiating normal from anomalous nutrition and fasting and for assessing the quality of inedia studies. Studies found through a systematic search were then assessed and the features of cases of fraud extracted. RESULTS: 47 eligible investigations of 38 claimants were found. Out of the 38 cases, results were assessed as (seemingly) anomalous in 11, with nine cases of monitored food and fluid deprivation ranging from 14 to 68 days (median 28 days), and two cases of food deprivation for 365 and 411 days. In 17 cases, anomaly was assessed as not confirmed due to issues with study design or reporting. Fraud was established in 10 cases. Deception methods were creative. Post-1900 studies were also assessed for quality. Quality was not considered adequate in any. CONCLUSIONS: I consider the evidential status of inedia unconfirmed as no assessed study had both anomalous findings and impeccable quality. However, quality was often downgraded due to reporting issues and it cannot be concluded in reverse that all claimants with anomalous results were able to deceive the investigators. The results of many studies are curious and demand further research. The conducted analysis provides guidance for improving rigor and transparency in future studies.

Evaluating steady-state resting energy expenditure using indirect calorimetry in adults with overweight and obesity.

BACKGROUND: Determining a period of steady state (SS) is recommended when estimating resting energy expenditure (REE) using a metabolic cart. However, this practice may be unnecessarily burdensome and time-consuming in the research setting. AIM: The aim of the study was to evaluate the use of SS criteria, and compare it to alternative approaches in adults with overweight and obesity. METHODS: In this cross-sectional, ancillary analysis, participants enrolled in a bariatric (study 1; n = 13) and lifestyle (study 2; n = 51) weight loss intervention were included. Indirect calorimetry was performed during baseline measurements using a metabolic cart for 25 min, including a 5-min stabilization period at the start. SS was defined as the first 5-min period with a coefficient of variation (CV) ≤10% for both VO2 and VCO2 (hereafter REE5-SS). Body composition was measured using bioelectrical impedance analysis in study 2 participants only. REE5-SS was compared against the lowest CV (REECV-lowest), 5-min time intervals (REE6-10, REE11-15, REE16-20, REE21-25), 4-min and 3-min SS intervals (REE4-SS and REE3-SS), and time intervals of 6-15, 6-20 and 6-25 min (REE6-15, REE6-20, and REE6-25) using repeated measures ANOVA and Bland-Altman analysis to test for bias, limits of agreement and accuracy (±6% measured REE). RESULTS: Participants were 54 ± 13 years old, mostly women (75%) and had a BMI of 35 ± 5 kg/m2. Overall, 54/63 (84%) of participants reached REE5-SS, often (47/54, 87%) within the first 10-min (6-15 min). Alternative approaches to estimating REE had a relatively low bias (-16 to 13 kcals), narrow limits of agreement and high accuracy (83-98%) when compared to REE5-SS, in particular, outperforming standard prediction equations (e.g., Mifflin St. Joer). CONCLUSION: Indirect calorimetry measurements that utilize the 5-min SS approach to estimate REE are considered the gold-standard. Under circumstances of non-SS, it appears 4-min and 3-min SS periods, or fixed time intervals of atleast 5 min are accurate and practical alternatives for estimating REE in adults with overweight and obesity. However, future trials should validate alternative methods in similar populations to confirm these findings.

Energy Expenditure in Older People Hospitalized for an Acute Episode.

Weight loss and worsening of nutritional state is a frequent downfall of acute hospitalization in older people. It is usually accepted that acute inflammation is responsible for hypercatabolism. However, several studies suggest, on the contrary, a reduction in resting energy expenditure (REE). This study aimed to obtain a reliable measure of REE and total energy expenditure (TEE) in older patients hospitalized for an acute episode in order to better assess patients' energy requirements and help understand the mechanisms of weight loss in this situation. Nineteen hospitalized older patients (mean age 83 years) with C-reactive protein (CRP) level >20mg/L were recruited. REE and TEE were measured using gold standard methods of indirect calorimetry and doubly labeled water (DLW), respectively. REE was then compared to data from a previous study on aged volunteers from nursing homes who were free of an acute stressor event. Energy requirements measured by DLW were confirmed at 1.3 × REE. Energy intake covered the needs but did not prevent weight loss in these patients. TEE was not increased in hospitalized patients and was not influenced by inflammation, while the relationship between REE and inflammation was uncertain. Our results suggest that lean mass remains the major determinant of REE in hospitalized older people and that weight loss may not be explained solely by a state of hypercatabolism.

Total energy expenditure in patients with colorectal cancer: associations with body composition, physical activity, and energy recommendations.

BACKGROUND: Total energy expenditure (TEE) data in patients with early-stage cancer are scarce, precluding an understanding of energy requirements. OBJECTIVE: The objective was to cross-sectionally characterize TEE in patients with colorectal cancer (CRC) and to compare measured TEE with energy recommendations. It was hypothesized that TEE would differ according to body mass, body composition, and physical activity level (PAL) and current energy recommendations would have poor individual-level accuracy. METHODS: Patients with newly diagnosed CRC had resting energy expenditure (REE) measured by indirect calorimetry and TEE by doubly labeled water. Hypermetabolism was defined as REE > 110% of that predicted from the Mifflin St.-Jeor equation. Body composition was assessed via DXA. Physical activity was determined as the ratio of TEE to REE (TEE:REE) (PAL) and residual activity energy expenditure (RAEE). TEE was compared with energy recommendations of 25-30 kcal/d and Dietary Reference Intakes (DRIs) using Bland-Altman analyses. Patients were stratified according to median BMI, PAL, and sex-specific ratio of fat mass (FM) to fat-free mass (FFM). RESULTS: Twenty-one patients (M:F 14:7; mean ± SD BMI: 28.3 ± 4.9 kg/m2, age: 57 ± 12 y) were included. Most (n = 20) had stage II-III disease; 1 had stage IV. Approximately half (n = 11) were hypermetabolic; TEE was not different in those with hypermetabolism and REE as a percentage of predicted was not correlated with TEE. Mean ± SD TEE was 2473 ± 499 kcal/d (range: 1562-3622 kcal/d), or 29.7 ± 6.3 kcal/kg body weight (range: 20.4-48.5 kcal/kg body weight). Mean ± SD PAL was 1.43 ± 0.27. The energy recommendation of 25 kcal/kg underestimated TEE (-12.6% ± 16.5%, P = 0.002); all energy recommendations had wide limits of agreement (the smallest was DRI with measured PAL: -21.2% to 29.3%). Patients with higher BMI and FM:FFM had higher bias using kilocalories per kilogram recommendations; bias from several recommendations was frequently lower (i.e. underestimation) in patients with higher PAL and RAEE. CONCLUSIONS: TEE variability was not reflected in energy recommendations and error was related to body weight, body composition, and physical activity. This trial was registered at clinicaltrials.gov as NCT03131921.

Transformation of atrazine by photolysis and radiolysis: kinetic parameters, intermediates and economic consideration.

Four techniques, UV254 nm photolysis, vacuum ultraviolet (VUV172 nm) photolysis, combined UV254 nm/VUV185 nm photolysis and gamma (γ) radiolysis were used to induce the transformation of atrazine in aqueous solution. The effects of dissolved oxygen (atrazine concentration 1 × 10-4 mol L-1 and 4.6 × 10-7 mol L-1) and matrix (high purity water/purified wastewater, atrazine concentration 4.6 × 10-7 mol L-1) and the electric energy requirements were investigated. The calculation of the energy input in cases of the photolyses was based on the lamp's power. In radiolysis, the absorbed dose (J kg-1) was the basis. In UV photolysis, atrazine transforms to atrazine-2-hydroxy; this product practically does not degrade during UV photolysis; due to this reason, the mineralisation is very slow. This and some other products of atrazine decomposition degrade only in radical reactions. Dissolved oxygen usually slightly enhances the degradation rate. At 10-7 mol L-1 concentration level, the matrix, high purity water/purified wastewater, has not much influence on the degradation rates in UV photolysis and radiolysis. In the VUV and UV/VUV systems, considerable matrix effects were observed. Comparing the electric energy requirements of the four degradation processes, radiolysis was found to be the economically most feasible method, requiring 1-2 orders of magnitude less electric energy than UV/VUV, VUV and UV photolysis.

The use of whole body calorimetry to compare measured versus predicted energy expenditure in postpartum women.

BACKGROUND: Accurate assessment of energy expenditure may support weight-management recommendations. Measuring energy expenditure for each postpartum woman is unfeasible; therefore, accurate predictive equations are needed. OBJECTIVES: This study compared measured with predicted resting energy expenditure (REE) and total energy expenditure (TEE) in postpartum women. METHODS: This was a longitudinal observational study. REE was measured at 3 mo postpartum (n = 52) and 9 mo postpartum (n = 49), whereas TEE was measured once at 9 mo postpartum (n = 43) by whole body calorimetry (WBC). Measured REE (REEWBC) was compared with 17 predictive equations; measured TEE plus breast milk energy output (ERWBC) was compared with the estimated energy requirements/Dietary Reference Intakes equation (EERDRI). Fat and fat-free mass were measured by dual-energy X-ray absorptiometry. Group-level agreement was assessed by the Pearson correlation, paired t test, and Bland-Altman (bias) analyses. Individual-level accuracy was assessed with the use of Bland-Altman limits of agreement, and by the percentage of women with predicted energy expenditure within 10% of measured values ("accuracy"). RESULTS: The cohort was primarily Caucasian (90%). At a group level, the best equation predicting REEWBC was the DRI at 3 mo postpartum (-7 kcal, -0.1%; absolute and percentage bias, respectively), and the Harris-Benedict at 9 mo postpartum (-17 kcal, -0.5%). At an individual level, the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) height and weight equation was the most accurate at 3 mo postpartum (100% accuracy) and 9 mo postpartum (98% accuracy), with the smallest limits of agreement. Equations including body composition variables were not more accurate. Compared with ERWBC, EERDRI bias was -36 kcal, with inaccurate predictions in 33% of women. CONCLUSIONS: Many REE predictive equations were accurate for group assessment, with the FAO/WHO/UNU height and weight equation having the highest accuracy for individuals. EERDRI performed well at a group level, but inaccurately for 33% of women. A greater understanding of the physiology driving energy expenditure in the postpartum period is needed to better predict TEE and ultimately guide effective weight-management recommendations.

Methods for data analysis of resting energy expenditure measured using indirect calorimetry.

OBJECTIVES: The aim of this study was to test the accuracy of different methods of resting energy expenditure (REE) data analysis using indirect calorimetry (IC) during traditional (30 min) and abbreviated (10 min) protocols. METHODS: Fifteen women and 15 men (21-34 y of age) completed two consecutive 30-min IC measurements. Body composition was measured using dual-energy x-ray absorptiometry. The reference method for REE analysis was 5 min in steady state (SS) during 30 min (first 5 min discarded). REE measurements were randomized to define a reference or testing method. An interval method was defined using 25, 20, and 15 min (with first 5, 10, and 15 min discarded, respectively), during 30 min, and 5 min (first 5 min discarded) during 10-min intervals. The SS method was defined using 5 min in SS (first 5 min discarded) during 30 min, 5, 4, and 3 min in SS during 10-min (first 5 min discarded) intervals. RESULTS: Interval methods during 30 min and SS and interval methods during 10 min demonstrated large bias with significantly high REEs compared to the reference method (78.8-109.0 kcal/d, all P < 0.001). Testing methods demonstrated large upper limits of agreement between 225.2 and 322.8 kcal/d. No mean differences (P > 0.05), small bias (14.3 kcal/d), and narrow limits of agreement (-125.8 to 154.4 kcal/d) were observed between 5-min SS during 30 min and the reference method. CONCLUSIONS: All interval methods and SS methods during 10 min overestimated REE. We recommend using 5-min SS during 30 min. The measurement may be repeated until all participants achieve SS.

Energy expenditure associated with walking speed and angle of turn in children.

PURPOSE: Recent studies have suggested that turning is power intensive. Given the sporadic and irregular movement patterns of children, such findings have important implications for the assessment of true energy expenditure associated with habitual physical activity. The purpose of this study was to investigate the influence of walking speed and angle, and their interaction, on the energy expenditure of healthy children. METHODS: 20 children (10.1 ± 0.5 years; 10 boys) participated in the study. On two separate days, participants completed a turning protocol involving 3-min bouts of walking at one of the 16 speed (2.5, 3.5, 4.5, and 5.5 km h- 1) and angle (0°, 45°, 90°, and 180°) combinations, interspersed by 3 min seated rest. The movement involved 5 m straight walking interspaced with prescribed turns with speed dictated by a digital, auditory metronome. Breath-by-breath gas exchange was measured, in addition to tri-axial acceleration and magnetic field intensity recorded at 100 Hz. RESULTS: Mixed models revealed a significant main effect for speed (p < 0.006) and angle (p < 0.006), with no significant interaction between speed and angle (p > 0.006). Significant differences to straight-line walking energy expenditure within speed were established for 3.5 and 5.5 km h- 1 for 180° turns (~ 13% and ~ 30% increase, respectively). CONCLUSION: These findings highlight the importance of accounting for the magnitude and frequency of turns completed when estimating children's habitual physical activity and have significant implications for the assessment of daily energy expenditure.

Assessment of parenteral nutrition prescription in Canadian acute care settings.

BACKGROUND: Parenteral nutrition (PN) prescription can be challenging in patients with complex conditions and has potential complications. OBJECTIVE: To assess PN prescription, monitoring, and PN-related complications in a Canadian acute care setting. METHODS: This was a prospective cohort study in which patients receiving PN were assessed by an auditor for nutritional status, PN-related prescription, monitoring, and complications. In addition, length of stay and mortality were recorded. RESULTS: 147 patients (mean ± SD 56.1 ± 16.4 y) with complex diseases (Charlson comorbidity index, median [p25-p75] 2 [1-4]) were enrolled. Before starting PN, 18.6%, 63.9%, and 17.5% of patients were classified as subjective global assessment A, B, and C, respectively. Body mass index remained unchanged during the period on PN. On average, 89% and 73% of patients received <90% of their energy and protein requirements, respectively, but 65% received oral or enteral nutrition at some point during PN. The average daily energy provided by PN increased and stabilized on day 10, reaching 87.2 ± 20.1% of the requirements. Line sepsis (6.8% of patients) and hyperglycemia (6.9%) were the most common complications. The overall mortality was 15.6%. For those alive, length of stay was 30 (range: 4-268) d. PN was discontinued because of transitioning to an oral diet (56.6%), enteral nutrition (17.6%), home PN (14.7%), palliative care (5.1%), death (4.4%), or other (1.5%). CONCLUSION: Most patients were malnourished at the start of PN. Energy and protein provided from PN were less than requirements, and the goals were reached with delay. Mortality was high, possibly as a result of complex diseases.

Energy expenditure of rugby players during a 14-day in-season period, measured using doubly labelled water.

Criterion data for total energy expenditure (TEE) in elite rugby are lacking, which prediction equations may not reflect accurately. This study quantified TEE of 27 elite male rugby league (RL) and rugby union (RU) players (U16, U20, U24 age groups) during a 14-day in-season period using doubly labelled water (DLW). Measured TEE was also compared to estimated, using prediction equations. Resting metabolic rate (RMR) was measured using indirect calorimetry, and physical activity level (PAL) estimated (TEE:RMR). Differences in measured TEE were unclear by code and age (RL 4369 ± 979; RU 4365 ± 1122; U16, 4010 ± 744; U20, 4414 ± 688; U24, 4761 ± 1523 Kcal day- 1). Differences in PAL (overall mean 2.0 ± 0.4) were unclear. Very likely differences were observed in RMR by code (RL 2366 ± 296; RU 2123 ± 269 Kcal day- 1). Differences in relative RMR between U20 and U24 were very likely (U16, 27 ± 4; U20, 23 ± 3; U24, 26 ± 5 Kcal kg- 1 day- 1). Differences were observed between measured and estimated TEE, using Schofield, Cunningham and Harris-Benedict equations for U16 (187 ± 614, unclear; - 489 ± 564, likely and - 90 ± 579, unclear Kcal day- 1), U20 (- 449 ± 698, likely; - 785 ± 650, very likely and - 452 ± 684, likely Kcal day- 1) and U24 players (- 428 ± 1292; - 605 ± 1493 and - 461 ± 1314 Kcal day- 1, all unclear). Rugby players have high TEE, which should be acknowledged. Large inter-player variability in TEE was observed demonstrating heterogeneity within groups, thus published equations may not appropriately estimate TEE.

Cost effectiveness of phosphorus removal processes in municipal wastewater treatment.

Meeting stringent phosphorus (P) discharge standards remains one of the major challenges for wastewater utilities due to increased economic burdens associated with advanced (i.e., secondary, tertiary) treatment processes. In a trade-off between higher treatment cost and enhanced P removal, it is critical for the treatment plants to be able to select the most appropriate technology. To this end, established/emerging high performing P removal/recovery technologies (e.g., Modified University of Cape Towne process, Bardenpho process, membrane bioreactors, IFAS-EBPR, struvite recovery, tertiary reactive media filtration) were identified and full-scale treatment plant designs were developed. Using advanced mathematical modeling techniques, six different treatment configurations were evaluated in terms of performance and cost effectiveness ($/lb of P removed). Results show that the unit cost for P removal in different treatment alternatives range from $42.22 to $60.88 per lb of P removed. The MUCT BNR + tertiary reactive media filtration proved to be one of the most cost effective configurations ($44.04/lb P removed) delivering an effluent with total P (TP) concentration of only 0.05 mg/L. Although struvite recovery resulted in significant reduction in biosolids P, the decrease in effluent TP was not sufficient to meet very stringent discharge standards.

Supplemental parenteral nutrition in intensive care patients: A cost saving strategy.

BACKGROUND & AIMS: The Swiss supplemental parenteral nutrition (SPN) study demonstrated that optimised energy provision combining enteral nutrition (EN) and SPN reduces nosocomial infections in critically ill adults who fail to achieve targeted energy delivery with EN alone. To assess the economic impact of this strategy, we performed a cost-effectiveness analysis using data from the SPN study. METHODS: Multivariable regression analyses were performed to characterise the relationships between SPN, cumulative energy deficit, nosocomial infection, and resource consumption. The results were used as inputs for a deterministic simulation model evaluating the cost-effectiveness of SPN administered on days 4-8 in patients who fail to achieve ≥60% of targeted energy delivery with EN by day 3. Cost data were derived primarily from Swiss diagnosis-related case costs and official labour statistics. RESULTS: Provision of SPN on days 4-8 was associated with a mean decrease of 2320 ± 338 kcal in cumulative energy deficit compared with EN alone (p < 0.001). Logistic regression analysis showed that each 1000 kcal decrease in cumulative energy deficit was associated with a 10% reduction in the risk of nosocomial infection (odds ratio 0.90; 95% confidence interval 0.83-0.99; p < 0.05). The incremental cost per avoided infection was -63,048 CHF, indicating that the reduction in infection was achieved at a lower cost. CONCLUSION: Optimisation of energy provision using SPN is a cost-saving strategy in critically ill adults for whom EN is insufficient to meet energy requirements.