Decrease In Resting Energy Expenditure Research Articles

Energy availability modulates regional blood flow via estrogen-independent pathways in regularly menstruating young women

PurposeThis study aimed to investigate the impact of short-term low energy availability (LEA) on vascular function in young, regularly menstruating women.MethodsParticipants were 19 women, aged 22.9 ± 4.2 years, with body mass index 18–30 kg·m2. They were divided into two groups and completed two conditions in a crossover design: a 3-day control condition (CON) with an energy availability of 45 kcals·kgFFM−1·day−1 and a 3-day LEA condition of 15 kcals·kgFFM−1 day–1. Assessments were conducted during the early follicular phase of the menstrual cycle. Outcome measures included forearm blood flow (FBF), heart rate, blood pressure, arterial stiffness, resting energy expenditure (REE), metabolic blood markers and body composition.ResultsSignificant time-by-condition interactions were found for resting FBF (p = .004), REE (p = .042), triiodothyronine (p = .006), β-hydroxybutyrate (p = .002) and body mass (p < .001). Resting FBF was 1.43 ± 1.01 and 1.31 ± 0.61 (arbitrary units) at pre and post, respectively, in LEA and 1.52 ± 0.7 and 1.76 ± 0.57 at pre and post in CON. The LEA condition led to a decrease in triiodothyronine (pre: 1.54 ± 0.28, post: 1.29 ± 0.27 ng ml−1), REE (pre: 1588 ± 165, post: 1487 ± 160 kcals day−1) and body mass (pre: 61.4 ± 7.5, post: 59.6 ± 7.3 kg). Changes in resting FBF were significantly correlated with changes in REE in the LEA condition (r = 0.53; p = 0.02).ConclusionShort-term LEA modifies regional blood flow and this might contribute to the observed decreased in REE. Findings emphasize the need for careful management of energy availability in populations at risk of LEA.

Resting energy expenditure depends on energy intake during weight loss in people with obesity: a retrospective cohort study.

Resting energy expenditure (REE) decreases if there is reduced energy intake and body weight (BW). The decrease in REE could make it difficult for patients with obesity to maintain decreased BW. This study aimed to investigate the correlation among changes in REE, energy intake, and BW during the weight loss process in patients with obesity. We conducted a retrospective cohort study of patients hospitalized for the treatment of obesity in Japan. Patients received fully controlled diet during hospitalization and performed exercises if able. REE was measured once a week using a hand-held indirect calorimetry. Energy intake was determined by actual dietary intake. Of 44 inpatients with obesity, 17 were included in the analysis. Their BW decreased significantly after 1 week (-4.7 ± 2.0 kg, P < 0.001) and 2 weeks (-5.7 ± 2.2 kg, P < 0.001). The change in REE after 1 and 2 weeks was positively correlated with the energy intake/energy expenditure ratio (r = 0.66, P = 0.004 at 1 week, r = 0.71, P = 0.002 at 2 weeks). Using a regression equation (y = 0.5257x - 43.579), if the energy intake/energy expenditure ratio within the second week was 82.9%, the REE after 2 weeks was similar to the baseline level. There was no significant correlation between the change in REE and BW. Our data suggest that changes in REE depend on energy intake/energy expenditure ratio and that the decrease in REE can be minimized by matching energy intake to energy expenditure, even during the weight loss process.

Relationships Between Resting Energy Expenditure and Transcranial Doppler Measurements in Patients With and Without Brain Death.

Introduction Brain metabolism deteriorates during brain death, suggesting that cerebral metabolic measurements could serve as a prognostic factor. The application of transcranial Doppler can be useful in evaluating patients evolving to brain death. Resting energy expenditure is lower than expected in patients with brain death, and this is caused by the decrease in cerebral blood flow and consequently lower oxygen supply. The primary aim of this retrospective study is to investigate the early metabolic changes in patients with clinical criteria of brain death and examine if these changes are related to a gradual decrease in blood flow velocities in the middle cerebral artery. Methods All consecutive patients from 1st June 2018 to 30th April 2022, admitted to the ICU with brain injury and a GCS ≤8, were included retrospectively in the study. Patients were allocated into two groups: Group A, patients without clinical signs of brain death (n = 32), and Group B, patients with brain death (n = 34). In each group, three sets of metabolic measurements were performed concomitantly with cerebral blood flow velocities using transcranial Doppler (a) upon admission to the ICU, (b) once hemodynamic stabilization was obtained, and (c) 48 hours after their hemodynamic stabilization or when brain death was confirmed by clinical criteria. Resting energy expenditure (REE) measurements were performed using a metabolic computer. Cerebral blood flow velocities were measured after a period of 30 min using a 2-MHZ 2D ultrasound probe. Results Brain-dead patients had a significant decrease in their metabolic parameters as the cerebral blood flow velocities recorded with the transcranial Doppler deteriorated, (REE Group A = 1667.65 ± 597 vs Group B = 1376.12 ± 615, p = 0.05 and REE predictedGroup A = 113.19 ± 44.9 vs Group B = 93.29 ± 41.5, p = 0.066 for measurement 1;REE Group A = 1844 ± 530.9 vs Group B = 1219.97 ± 489, p < 0.001 and REE predictedGroup A = 124.38 ± 39 vs Group B = 81.35 ± 30.4, p < 0.001 for measurement 2; REE Group A = 1750.97 ± 414, p < 0.001 and REE predicted Group A = 116.38 ± 19.2 vs Group B = 56.09 ± 19.6, p < 0.001 for measurement 3).Multiple stepwise regression analysis revealed a strong relationship between age, the worsening of the blood flow velocities pattern, and the decrease in REE (multiple R = 0.264, F = 5.55, p = 0.009).Furthermore, a statistically significant correlation was found between temperature and REE (correlation coefficient = 0.500, 0.674, 0.784 for measurements 1, 2, and 3, respectively, and p < 0.001 for all measures). Conclusions In brain-dead patients, the gradual decrease in cerebral blood flow leads to a decrease in REE as well as thermogenetic control. These changes can be detected early after the patient's admission to the ICU.

Resting energy expenditure in preterm newborns with bronchopulmonary dysplasia.

Greater energy expenditure is reported in newborns with bronchopulmonary dysplasia (BPD). This study assessed resting energy expenditure (REE) in newborns with BPD. BPD was classified as mild and moderate/severe. REE was assessed using indirect calorimetry between the time points of the discontinuation of oxygen (O2) (T1) and at term-equivalent age (T2) in preterm newborns with BPD. The moderate group (10 newborns) presented with higher REE (kcal/kg/day) after discontinuation of mechanical ventilation and a decrease of 18% between the two time points; 72.7 and 59.6kcal/kg/day at T1 and T2 respectively (p value 0.08). No differences were observed in REE in the mild BPD group between timepoints; 50.9-56.4kcal/kg/day at T1 and T2 respectively (p value 0.73). Newborns with BPD presented different metabolic behaviors depending on the classification criteria: those classified as having moderate BPD showed a decrease in REE toward term-equivalent age.

A Randomized Clinical Trial to Compare a Precision Nutrition Intervention Targeting a Reduction in Postprandial Glycemic Response to Meals With a Low-Fat Diet for Weight Loss

ObjectivesThe primary aim is to compare the effects of a low-fat diet vs a personalized diet on % weight loss at 6-months. Secondary outcomes include body composition (fat mass [FM] and fat free mass [FFM]), resting energy expenditure (REE) and adaptive thermogenesis (AT).MethodsThe Personal Diet Study was a 6-month, single-center, randomized clinical trial in adults with pre-diabetes and moderately controlled type 2 diabetes who were overweight or obese. Participants were randomized to follow either a hypocaloric low-fat diet, with < 25% energy intake from total fat (Standardized), or a hypocaloric personalized diet determined by a machine learning algorithm which predicts PPGR to meals (Personalized). Participants in both arms received behavioral counseling and logged dietary intake and physical activity into a smartphone app. Participants in the Personalized arm received real-time feedback as color-coded scores based on pre-consumed meals entered into the smartphone app. T-tests were used to assess group differences.ResultsA total of 200 adults (Standardized: n = 97 vs. Personalized: n = 103) contributed data (mean [SD]: age, 58 [11] years; 67% female; BMI, 34.0 [4.8] kg/m2; HbA1c, 5.8 [0.6]%; Metformin use, 21.0%). There were no significant group differences in mean % weight loss (Standardized: −4.4 [4.8]% vs Personalized: −3.3 [5.4]%; p = 0.19), mean absolute change in FM (Standardized: −2.7 [3.4] kg vs. Personalized: −1.6 [3.5] kg; p = 0.18), and AT between the two arms (Standardized: −54.7 [177] kcal/d vs. Personalized: 26.2 [199] kcal/d; p = 0.078). However, the Standardized arm lost significantly more FFM (−1.4 [1.6] kg vs. −0.45 [2.0] kg; p = 0.03) and had a greater decrease in REE (−111.0 [195.0] kcal/d vs. 1.93 [215.0] kcal/d; p = 0.02) compared to Personalized.ConclusionsA personalized diet to minimize PPGR had no greater effect on % weight loss compared to a low-fat diet at 6-months. Future precision nutrition trials may require deeper phenotyping of individuals or the development of body weight-specific algorithms.Funding SourcesSupported by grants from the American Heart Association 17SFRN33590133.

The effect of selective hypothermia of the cerebral cortex on metabolism in patients with prolonged impairment of consciousness

BACKGROUND: Selective craniocerebral hypothermia, used in the acute period of brain damage, ensures the development of positive clinical effects (rapid and persistent reduction of neurological deficit, increased consciousness, and maintenance of normothermy in feverish patients). The safety and efficacy of craniocerebral hypothermia in the acute period of cerebrovascular lesions prompted the use of craniocerebral cooling in patients with chronic disorders of consciousness. For this category of patients, the craniocerebral hypothermia technique has been developed, which requires careful study including its effect on overall metabolism.&#x0D; AIMS: To determine the nature of the metabolic response to craniocerebral hypothermia procedures in patients in a vegetative state and minimal conscious state.&#x0D; MATERIALS AND METHODS: A pilot study was conducted from February 3, 2021 until March 3, 2022. This study included 34 patients who were in a state of chronic disorders of consciousness, CRS-R score of 8 (vegetative state and minimally conscious state), after severe brain damage (stroke, 25; brain injury, 5; anoxic brain injuries, 4). Hypothermia was induced using the ATG-01 device, lowering the temperature of the scalp to 47C with a cooling procedure lasting for 120 min. The indirect calorimetry method was conducted before cooling and after 105 min of the craniocerebral hypothermia session. Statistical analysis was performed using the program StatTech v. 2.6.5 (StarTech LLC, Russia).&#x0D; RESULTS: Craniocerebral cooling provided a decrease in the temperature of the frontal cortex of the large hemispheres already after 30 min from 36.4C to 34.90.41C in the left hemisphere and 34.70.47C in the right hemisphere. By the 120th minute, the temperature in the left hemisphere reached 34.00.40C, and that in the right hemisphere reached 33.30.51C, decreasing by 2.4C and 3.1C, respectively. Subsequently, 30 min after the completion of craniocerebral hypothermia, the brain temperature remained lowered by 0.7C. Changes in the level of metabolism under the influence of craniocerebral hypothermia were of a multidirectional nature. In 24 patients (70.59%), the resting energy expenditure (REE) index increased to varying degrees by the end of the cooling procedure, and in 10 participants, it decreased. A significant spread of data allowed only a descriptive analysis of the results obtained during a 120-min craniocerebral hypothermia session.&#x0D; CONCLUSIONS: Chronic disorders of consciousness are largely associated with severe damage of the cerebral cortex. It can be assumed that in patients who reacted with a decrease in REE to the induction of hypothermia, at least metabolic activity in the intact parts of the cerebral cortex was preserved to a certain extent, which may indicate some level of rehabilitation potential. The lack of expression of the reactions of the general metabolism to craniocerebral cooling may be due to the fact that the severe damage to the cerebral cortex excluded the selectivity of hypothermic exposure.

Effect of Intermittent Fasting (18/6) on Energy Expenditure, Nutritional Status, and Body Composition in Healthy Adults.

Objective This study was aimed at evaluating the effect of intermittent fasting of Ramadan on resting energy expenditure (REE), body composition, and nutritional status. Methods The study was conducted on a total of 27 adults (16 females, 11 males) who were fasting (18 h) in the Ramadan month (May 6–June 3) of 2019. REE was measured using the indirect calorimeter. Dietary energy and nutrient intakes were evaluated by 3-day food records in baseline and post-Ramadan. Body composition and some metabolic parameters were analyzed simultaneously with REE measurements. All measurements were performed two times at baseline, and post-Ramadan. Results Body weight (−2.9% vs. −1.4%), body mass index (BMI) (−3.1% vs. −2.1%), fat-free mass (−2.7% vs. −1.4%), and hydration status were decreased in both males and females after the Ramadan fasting (p < 0.05). REEs (kcal/d) of the participants were 1708.1 ± 262.50 kcal/d and 1596.5 ± 302.27 kcal/d at baseline and post-Ramadan, respectively (6.5%) (p < 0.05). This decrease in REE (kcal/d) in females was greater than that in males (−8.1% vs. −4.6%). However, no statistically significant difference was found in sleep duration (h), physical activity levels, dietary energy and nutrient intakes, and blood pressures (mm Hg) of both genders compared to baseline (p > 0.05). Conclusion Intermittent circadian fasting may lead to a decreased energy expenditure and a change in fat-free mass in healthy individuals, and this effect is interpreted as gender-dependent.

Comparative assessment of energy metabolism, body composition and metabolic features in children with hypothalamic and simple obesity

Background: Hypothalamic obesity often develops after surgical treatment of craniopharyngioma and is characterized by rapid weight gain, high frequency of metabolic disorders, body composition specificity and resistance to standard lifestyle modification approaches and medication therapy of obesity. Recent studies show that one of the mechanisms, explaining weight gain in these children is decrease in resting energy expenditure (REE).Aims: To compare REE, body composition parameters, and the frequency of metabolic disorders in children with hypothalamic and simple obesity.Materials and methods: The study included 60 obese children aged 7 to 17 years, divided into two groups. The study group included 20 children with hypothalamic obesity, developed after craniopharyngioma treatment. The control group consisted of 40 children with simple obesity. Body composition, REE, and metabolic disorders were associated in all children.Results: Children with hypothalamic obesity showed a significant decrease of resting energy expenditure. The average decrease in REE was 13.1%, but in single patients it reached 33.4%. The percentage of fat mass in hypothalamic and simple obesity does not differ significantly (39.7% [36.2; 42.6] vs 38.8 % [35.9; 43.2]; p=0.69). Screening for metabolic disorders revealed a high prevalence of metabolic disorders in hypothalamic obesity: impaired glucose tolerance - in 10%; dyslipidemia - 55%, insulin resistance-50%, non-alcoholic fatty liver disease - 60 %.Conclusions: Children with hypothalamic obesity showed a significant decrease of resting energy expenditure. When planning a diet in this group of patients it is preferable to use indirect calorimetry. Hypothalamic obesity even at an early age is associated with a high frequency of metabolic disturbance. Hypothalamic obesity in children is not associated with more pronounced hyperinsulinemia and insulin resistance compared to the simple obesity.

Body Weight Changes in Hyperthyroidism: Timing and Possible Explanations during a One Year Repeated Measurement Study

Background: Weight gain during treatment of hyperthyroidism is a frequent and for many patients unwanted outcome. With this repeated measurement study, we explored the timing of weight changes during the first year of antithyroid drug (ATD) treatment and assessed the correlation between body weight changes and changes in thyroid hormones, resting energy expenditure (REE), physical activity level, and energy efficiency. Methods: Patients with new onset hyperthyroidism were investigated every second month during the first year of ATD treatment. At each investigation, the following were measured: body weight, thyroid hormone concentrations, physical activity level, and daily number of steps, REE, and exercise performance. Results: Two men and eleven women, all sedentary, mean age 49(SD: 9.3) years were included. Significant changes after 1 year occurred for body weight (68.9–74.1 kg), thyroid hormones (free T3 [fT3] 17.5 to 4.42 pmol/L), REE (1,630–1,484 kcal/24 h), and energy efficiency at lower (50 W) workloads (16.0–17.6%). In individual patients, only REE and fT3 correlated to changes in body weight. Physical activity level did not change during treatment. Conclusion: In this study, treatment of hyperthyroidism was associated with marked increase in body weight in the patients. This increase correlated to a decrease in REE and only to a negligible extent to changes in energy efficiency and not at all to changes in physical activity level of daily living.

Early changes in appetite and energy expenditure are not associated to body weight and fat losses in pre-menopausal women living with overweight/obesity

The aim of the study was to investigate whether early changes (1-week) in energy balance-related measures would predict changes in body weight (BW) and fat losses in women living with overweight/obesity. BW, body composition (DXA), resting energy expenditure (REE)(indirect calorimetry), olfactory performance (Sniffin' Sticks), appetite and palatability (visual analogue scale) were measured at baseline, after a 1-week of caloric restriction as well as post-intervention (at 10 and 20 weeks) in a group of 30 women living with overweight/obesity. A significant decrease in REE (p=0.033) was noted after 1 week. Fasting desire to eat (p=0.004), hunger (p=0.001) and prospective food consumption (p=0.001) all increased after 1 week. Similarly, significant increases in AUC SQ for desire to eat (p=0.01), hunger (p=0.005) and prospective food consumption (p=0.001) were noted after 1 week. However, these early changes were not associated to final BW or FM losses at the end of the weight loss intervention. Despite significant changes in REE and appetite soon after the onset of a BW loss intervention, these early changes do not seem to predict final BW or FM losses at the end of the program in women living with overweight/obesity.

P112 Body composition and resting energy expenditure in IBD patients receiving biological therapy

Abstract Background As a feature of changing phenotype of IBD in the last decade, we observe increased rates of obesity and increased BMI values as well as changes in body composition. Special interest is the impact of biological therapy on body composition and prevalence of obesity in IBD patients, since the data on this topic are limited. The aim of this study was to determine body composition and resting energy expenditure of patients treated with biological therapy. Methods The study included 74 patients (39 male and 35 female) at the Clinical Hospital Center Zagreb (52 patients with Crohn’s disease and 22 with ulcerative colitis) treated with infliximab/adalimumab/ustekinumab/vedolizumab. Resting energy expenditure was measured by the indirect calorimetry (Cosmed Quark CPET) and compared with the predicted resting energy expenditure calculated using Harris-Benedict equation. Detailed medical and nutritional anamnesis was taken and we measured the following body composition parameters using TANITA body composition analyser, BC-420MA: body mass index (BMI), fat mass (FM), visceral fat rating (VFR), muscle mass (MM) and skeletal muscle mass index (SMI) was calculated. Results Increased BMI was observed in 32% of the patients, while 41% of the whole sample had an increased FM. The mean value of skeletal muscle index (SMI) was 9,061,15 kg m−2 and it revealed the presence of moderate sarcopenia in 32 patients (43%), of which 30 were men. Indirect calorimetry (IC) obtained the value of resting energy expenditure (REE), with the measured REE (1569,81240,95 kcal) on average significantly lower than predicted (1640,36255,28 kcal), t(73)=−3.023, p &amp;lt; 0.05. The results of this study revealed a significant prevalence of moderate sarcopenia in men, increased body mass and fat mass, and slightly lowered resting energy expenditure. There was no significant difference between body composition parameters and REE between different types of biological therapy. Conclusion The incidence of classical forms of malnutrition in this group of patients is significantly lower in comparison with standard therapy and previous experience. Most of the patients were well nourished and we observed trends toward overweight and sarcopenic obesity in some patients. A slight decrease in REE in the whole sample could be a reflection of impact of biological therapy on fat tissue and profound modulation of lipid metabolism as well as decreased muscle mass and physical activity level of the patients.

The effects of chemotherapy on energy metabolic aspects in cancer patients: A systematic review

Cancer survival rates have increased significantly creating more awareness for comorbidities affecting the Quality of Life. Chemotherapy may induce serious metabolic alterations. These complications can create an energy imbalance, worsening prognosis. The effect of chemotherapy on energy metabolism remains largely unknown. The purpose of this systematic review is to determine the impact of chemotherapy on energy metabolism, creating more insight in a patients' energy requirements. We identified relevant studies up to May 2nd, 2019 using PubMed and Web of Science. Studies including all types of cancer and stages were selected. Only patients that underwent chemotherapy whether or not followed by surgery or radiotherapy were selected. Maximum follow-up was set at 6 months. Resting energy expenditure (REE), measured by indirect calorimetry (IC) or predicted by the Harris-Benedict equation (HBEq), was our primary outcome. Results regarding body composition were considered as secondary outcome parameter. 16 studies were selected, including 267 patients. Overall, a significant decrease in REE [-1.5% to-24.91%] 1-month post-chemotherapy was reported. Two studies on breast cancer conducted a 3 and 6-month follow-up and found an increase in REE of 4.01% and 5.72% (p<.05), revealing a U-shaped curve in the expression of REE. Changes are accompanied by (non)significant variations in body composition (Fatmass (FM) and Fatfree Mass (FFM)). HBEq tends to underestimate REE by 4.03%-27.1%. Alterations in REE, accompanied by changes in body composition, are found during and after chemotherapy in all cancer types and stages, revealing a U-shaped curve. Changes in FFM are suggested to induce variations in REE concomitant to catabolic effects of the disease and administered drug. HBEq tends to underestimate REE, stressing the need for adequate assessment to meet patients' energy requirements and support dietary needs.

Changes in Energy Expenditure of Patients with Obesity Following Bariatric Surgery: a Systematic Review of Prospective Studies and Meta-analysis.

We herein summarize the available literature on the effects of bariatric surgery (BS) on energy expenditure in individuals with obesity. We conducted a systematic literature review, and 35 prospective studies met our inclusion criteria. The findings indicate that BS contributes to increased diet-induced thermogenesis (DIT) and decreased total energy expenditure (TEE) and resting energy expenditure (REE) in patients with obesity. The meta-analysis demonstrated a significant decrease in TEE and REE within 6months following BS. With the sustained decrease in REE, there was no further decrease in TEE between the 6- and 12-month follow-up. Increased DIT might explain the variance between the patterns of REE and TEE change. The postoperative decrease in REE/FFM and increase in REE/BW were observed. The changes in substrate utilization might be consistent with the change in the respiration quotient postoperatively.

Association of FTO and ADRB2 gene variation with energy restriction induced adaptations in resting energy expenditure and physical activity.

BackgroundEnergy restriction induces adaptations in resting energy expenditure (REE) and physical activity; inter-individual variability could be ascribed to genetic predisposition.The aim was to examine if changes in REE and physical activity as a result of weight loss were affected by candidate single nucleotide polymorphisms (SNPs).Methods148 subjects (39 men, 109 women), mean ± SD age: 41 ± 9 year; body mass index (BMI): 31.9 ± 3.0 kg/m2, followed a very low energy diet for 8 weeks. SNPs were selected from six candidate genes: ADRB2, FTO, MC4R, PPARG2, PPARD and PPARGC1A. REE (ventilated hood) and physical activity (tri-axial accelerometer) were assessed before and after the diet. General linear modelling included gender, age and additional relevant covariates for all parameters.ResultsThe heterozygotic genotype of FTO was associated with a higher amount of physical activity (1.71 Mcounts/d; CI 1.62–1.81) compared to the homozygotic major genotype (1.50 Mcounts/d; CI 1.40–1.59) (P < 0.001) while the homozygotic risk allele genotype was not different (1.56 Mcounts/d; CI 1.39–1.74) at baseline; moreover, a similar pattern was observed after energy restriction. Carrying the homozygotic minor genotype of ADRB2 was associated with a larger decrease in REE (P < 0.05) and greater adaptive thermogenesis (P < 0.05) after weight loss.ConclusionCarrying the minor ADRB2 allele homozygous was associated with a larger diet induced metabolic adaptation in energy expenditure and suggest a central role for reduced lipid mobilization. Carrying the risk allele of FTO homozygous was not associated with lower physical activity at baseline or after weight loss. Heterozygous carriers of one FTO risk allele showed greater physical activity before and after weight loss which might protect them in part from the higher obesity risk associated with FTO.

No consistent evidence of a disproportionately low resting energy expenditure in long-term successful weight-loss maintainers

Evidence in humans is equivocal in regards to whether resting energy expenditure (REE) decreases to a greater extent than predicted for the loss of body mass with weight loss, and whether this disproportionate decrease in REE persists with weight-loss maintenance. We aimed to1) determine if a lower-than-predicted REE is present in a sample of successful weight-loss maintainers (WLMs) and 2) determine if amount of weight loss or duration of weight-loss maintenance are correlated with a lower-than-predicted REE in WLMs. Participants (18-65 y old) were recruited in 3 groups: WLMs (maintaining ≥13.6 kg weight loss for ≥1 y, n=34), normal-weight controls [NCs, body mass index (BMI; in kg/m2) similar to current BMI of WLMs, n=35], and controls with overweight/obesity (OCs, BMI similar to pre-weight-loss maximum BMI of WLMs, n=33). REE was measured (REEm) with indirect calorimetry. Predicted REE (REEp) was determined via 1) a best-fit linear regression developed with the use of REEm, age, sex, fat-free mass, and fat mass from our control groups and 2) three standard predictive equations. REEm in WLMs was accurately predicted by equations developed from NCs and OCs (±1%) and by 3 standard predictive equations (±3%). In WLMs, individual differences between REEm and REEp ranged from -257 to +163 kcal/d. A lower REEm compared with REEp was correlated with amount of weight lost (r=0.36, P<0.05) but was not correlated with duration of weight-loss maintenance (r=0.04, P=0.81). We found no consistent evidence of a significantly lower REE than predicted in a sample of long-term WLMs based on predictive equations developed from NCs and OCs as well as 3 standard predictive equations. Results suggest that sustained weight loss may not always result in a substantial, disproportionately low REE. This trial was registered at clinicaltrials.gov as NCT03422380.

Resistance training during a 12-week protein supplemented VLCD treatment enhances weight-loss outcomes in obese patients

This investigation evaluated the efficacy by which resistance training enhances body composition, metabolic, and functional outcomes for obese patients undergoing a 12-week medically supervised hypocaloric treatment. This was a single-blind, randomized, parallel-group prospective trial. Morbidly obese patients were prescribed a 12-week proprietary very low calorie diet (VLCD) treatment (Optifast®) with supplemental protein (1120kcals/day) and were placed in one of two groups for 14 weeks: 1) Standard Treatment Control (CON) (n=5) or 2) Resistance Training (RT) (n=6). Both groups underwent a pedometer-based walking program; however only RT performed resistance training 3 days/week for 12 weeks. Body composition, resting energy expenditure (REE), neuromuscular function, and serum biomarkers were measured at weeks 0, 6, and 13. Both groups exhibited a significant loss of total body mass (TBM) (CON:-19.4±2.3kg, p=0.0009 vs. RT:-15.8±1.5kg, p=0.0002) and fat mass (FM) (CON:-14.7±1.8kg, p=0.0002 vs. RT:-15.1±2.1kg, p=0.0002) with no group differences. CON lost 4.6±0.8kg (p=0.004) of lean mass (LM) while RT demonstrated no changes. Group differences were found for the relative proportion of total weight-loss due to FM-loss (CON: 75.6±3.4% vs. RT: 96.0±6.0%, p=0.03) and LM-loss (CON: 24.4±3.2% vs. RT: 4.0±6.5%, p=0.03). CON demonstrated a 328.6±72.7kcal/day (-14.3±2.4%) (p=0.02) decrease in REE while RT exhibited a non-significant decrease of 4.6±1.6% (p=0.78). RT demonstrated greater improvements in all measures of contractile function and strength when compared to CON (p<0.05). At post-treatment, RT exhibited greater serum free fatty acids (p=0.01), glycerol (p=0.003), and β-hydroxybutyrate (p=0.005) than CON. Resistance training was advantageous for weight-loss composition by preservation of LM without compromising overall weight- or fat-loss in morbidly obese men and women undergoing a protein supplemented VLCD. These changes accompanied positive adaptations for resting metabolism and muscular function.

Nutritional status, energy expenditure, and protein oxidative stress after kidney transplantation

ABSTRACTObjectives: To evaluate the association between nutritional status, resting energy expenditure (REE), and protein oxidative stress in patients after kidney transplantation (KT).Methodology: The study evaluated 35 patients transplanted at the time of hospital discharge and 3 months after regarding: body composition, REE (by indirect calorimetry), and injury factor (IF); serum urea, creatinine, glucose, albumin, total protein, advanced oxidation protein products (AOPP), vitamin C.Results: Three months after discharge, there was an improvement in renal function, nutritional status, and oxidative stress, with a standardization in the REE/kg. There was an increase in body weight, mainly in fat mass. The correlations showed that a greater cold ischemia time resulted in a deeper decline in vitamin C; a longer hospital length stay resulted in a greater reduction in AOPP; the higher preoperative body weight showed greater increases in body fat and glucose after transplantation. For decreases in REE and IF, there were increases in total protein. Finally, at hospital discharge there was a greater gain in weight, lower albumin, and total protein among individuals who had rejection episodes.Discussion: The KT improves many of metabolic abnormalities, with the improvement of nutritional status, oxidative stress, and normalization of REE.

Impact of metabolic syndrome on resting energy expenditure in patients with chronic kidney disease

Resting energy expenditure (REE) changes in patients with chronic kidney disease (CKD) may contribute to mortality increase. The obesity and inflammation is associated with high REE and when not compensated by adequate intake, may determine an unfavorable clinical outcome in this population. We aimed to evaluate the influence of metabolic syndrome (MetS) on REE in CKD patients. One hundred eighty-three patients were stratified according to glomerular filtration rate (GFR) and divided in groups: without CKD (GFR>60ml/min/1.73m2) and CKD (GFR<60ml/min/1.73m2) and according to the presence or absence of MetS. REE was measured by indirect calorimetry; body composition was assessed by bioelectrical impedance analysis and blood and urine were collected for biochemical tests. REE was lower in the group with CKD compared with those without CKD (1293±364 vs 1430±370kcal/d, P=0.01). The group with CKD without MetS showed decrease in REE compared to the groups without CKD, regardless the presence of Mets, and those with CKD and MetS (1173±315 vs 1392±324 vs 1460±410 vs 1424±376kcal/d, P<0.05, respectively). Multivariate analysis showed an independent association of CKD in determining REE when adjusted for lean body mass. The inclusion of MetS as an independent variable in the same analysis model neutralized the impact of CKD on the REE (P=0.19). Patients without MetS, REE correlated with estimated GFR and the protein equivalent (r=0.33, P<0.01, r=0.21, P=0.04, respectively), whereas in MetS patients, these correlations were not observed. The presence of CKD is independently associated with reduced REE. The observed decrease in REE is reversed in patients with MetS independent of renal function.

Age-Dependent Changes in Resting Energy Expenditure (REE): Insights from Detailed Body Composition Analysis in Normal and Overweight Healthy Caucasians.

Age-related changes in organ and tissue masses may add to changes in the relationship between resting energy expenditure (REE) and fat free mass (FFM) in normal and overweight healthy Caucasians. Secondary analysis using cross-sectional data of 714 healthy normal and overweight Caucasian subjects (age 18–83 years) with comprehensive information on FFM, organ and tissue masses (as assessed by magnetic resonance imaging (MRI)), body density (as assessed by Air Displacement Plethysmography (ADP)) and hydration (as assessed by deuterium dilution (D2O)) and REE (as assessed by indirect calorimetry). High metabolic rate organs (HMR) summarized brain, heart, liver and kidney masses. Ratios of HMR organs and muscle mass (MM) in relation to FFM were considered. REE was calculated (REEc) using organ and tissue masses times their specific metabolic rates. REE, FFM, specific metabolic rates, the REE-FFM relationship, HOMA, CRP, and thyroid hormone levels change with age. The age-related decrease in FFM explained 59.7% of decreases in REE. Mean residuals of the REE-FFM association were positive in young adults but became negative in older subjects. When compared to young adults, proportions of MM to FFM decreased with age, whereas contributions of liver and heart did not differ between age groups. HOMA, TSH and inflammation (plasma CRP-levels) explained 4.2%, 2.0% and 1.4% of the variance in the REE-FFM residuals, but age and plasma T3-levels had no effects. HMR to FFM and MM to FFM ratios together added 11.8% on to the variance of REE-FFM residuals. Differences between REE and REEc increased with age, suggesting age-related changes in specific metabolic rates of organs and tissues. This bias was partly explained by plasmaT3-levels. Age-related changes in REE are explained by (i) decreases in fat free mass; (ii) a decrease in the contributions of organ and muscle masses to FFM; and (iii) decreases in specific organ and tissue metabolic rates. Age-dependent changes in the REE-FFMassociation are explained by composition of FFM, inflammation and thyroid hormones.

Hypermetabolism: should cancer types, pathological stages and races be considered in assessing metabolism and could elevated resting energy expenditure be the therapeutic target in patients with advanced cancer?

Hypermetabolism, defined as elevated resting energy expenditure (REE), was common in cancer cachectic patients1 as published before in cancer patients2 and might result in poor outcomes. In this study, there was no significant difference in age, cancer type, gender, cancer treatment and inflammation between elevated REE group and normal REE group. As authors indicated, the small sample size, the heterogeneous population and the selection bias could have some impacts on the findings. Regarding the sample size, a moderately large study, including 714 cancer patients, suggested that cancer type, pathological stage and duration of disease are contributors to metabolic activity.2 To keep the homogeneity of the study population, Wu et al. enrolled 56 male patients as newly diagnosed with esophageal cancer and showed that the rate of weight loss positively correlated with the ration of REE to body weight and high-sensitivity C-reactive protein.3 In addition, it is well known that less than 5% of cancer patients participate in clinical studies and that non-enrollment in cancer research was associated with older age and sex (female),4 which might facilitate the selection bias. In this study, hypermetabolism is more common in non-Caucasian patients than in Caucasian patients.1 Interestingly, non-Caucasian healthy subjects had a lower REE compared with Caucasian healthy subjects,5 and a similar trend was observed in obese patients.6 It is still controversial whether racial background influences metabolic response in various pathophysiological conditions such as obesity, diabetes and cancer cachexia. At present, the number of cachexia research is critically lacking compared with that of obesity research, and7 no other evidence has been published on racial differences in REE among cancer patients, in particular cancer cachectic patients. It remains unclear whether hypermetabolism could be the therapeutic target in advanced cancer patients; however, recently, Ma et al. reported that administration of omega-3 polyunsaturated fatty acids resulted in a significant decrease in REE and a significant increase in overall survival in patients with pancreatic cancer.8 As sustained hypermetabolism leads to muscle wasting, some drugs such as ghrelin agonists, selective androgen receptor molecules, megestrol acetate, activin receptor antagonists, espindolol, and fast skeletal muscle troponin inhibitors,9 as well as physical exercise,10 which are promising for the treatment or the prevention of muscle wasting, could be the candidates as therapeutic options for this condition. To clarify the pathophysiology of hypermetabolism in cancer patients, validation studies on larger samples, various cancer types, different pathological stages and races are needed. In addition, hypermetabolism could be the therapeutic target at least in a sub-population of cancer patients. To confirm it, further research is needed.