Resting Energy Expenditure of Children and Adolescents With Nonalcoholic Fatty Liver Disease

Background:The mainstay of treatment for pediatric nonalcoholic fatty liver disease (NAFLD) is lifestyle modification, which includes dietary changes that lead to slow but sustained weight loss or weight stabilization in growing children. Accurate estimation of energy requirements is necessary to achieve this goal. The objective of this study was to assess the accuracy of the most commonly used equations in predicting the resting energy expenditure (REE) of children with NAFLD. Methods: This was a retrospective study performed in a single institution. The predictive accuracy of various equations was assessed by comparing their estimates against the measured REE obtained with indirect calorimetry. Accuracy was defined as an estimate within 10% of measured REE. Results: Fifty‐six children (70% male; 52% white and 36% Asian) with a median age of 13 years were included. The median measured REE was 1829 kcal/d. Of the equations studied, the Schofield had the smallest average bias (–32 kcal/d; confidence interval, –121 to 56). The Schofield and Molnar equations were the most accurate, providing REE estimates within 10% of measured in 59% of cases. The remaining equations had lower and variable predictive accuracy. The use of adjusted body weight in predictive equations did not improve the predictive accuracy. Conclusion: In a cohort of children and adolescents with NAFLD, the Schofield and Molnar equations performed best in predicting energy expenditure. However, predictive equations were often inaccurate, suggesting that clinicians should interpret their results with caution and consider using indirect calorimetry when available.     

Energy expenditure is very high in extremely obese women

To test the hypothesis that total energy expenditure (TEE) and resting energy expenditure (REE) are low in extremely obese individuals, factors that could contribute to maintenance of excess weight, a cross-sectional study was conducted in 30 weight stable, extremely obese women [BMI (mean +/- SEM) 48.9 +/- 1.7 kg/m(2)]. TEE was measured over 14 d using the doubly labeled water method, REE and the thermic effect of feeding (TEF) were measured using indirect calorimetry, and activity energy expenditure (AEE) was calculated as TEE - (REE + TEF). Body composition was determined using a 3-compartment model. Subjects were divided into tertiles of BMI (37.5-45.0; 45.1-52.0; and 52.1-77.0 kg/m(2)) for data analysis. TEE and REE increased with increasing BMI tertile: TEE, 12.80 +/- 0.5, 14.67 +/- 0.5, and 16.10 +/- 0.9 MJ/d (P < 0.01); REE, 7.87 +/- 0.2, 8.78 +/- 0.3, and 9.94 +/- 0.6 MJ/d (P < 0.001), and these values were 29-38% higher than published means of measured TEE in nonobese individuals. No significant differences were observed among BMI tertiles for AEE, TEF, or physical activity level (PAL = TEE/REE, overall mean 1.64 +/- 0.16). The Harris-Benedict and WHO equations provided the closest estimates of REE (within 3%), whereas the obese-specific equations of Ireton-Jones overpredicted (40%) and Bernstein underpredicted (21%) REE. Extremely obese individuals have high absolute values for TEE and REE, indicating that excess energy intake contributes to the maintenance of excess weight. Standard equations developed for nonobese populations provided the most accurate estimates of REE for the obese individuals studied here. REE was not accurately predicted by equations developed in obese populations.     

Energy Expenditure in Patients With Esophageal,Gastric, and Colorectal Cancer

Background: Changes in resting energy expenditure (REE) appear to be one of the causes of nutritional depletion in cancer. Assessing REE may be an important tool for providing adequate nutritional therapy to these patients. The aims of this study were to evaluate REE of patients with gastrointestinal tract cancer and to compare it to that of healthy controls. Methods: A total of 20 patients, with esophageal (n = 3), gastric (n = 9), and colorectal (n = 8) cancers, and 20 healthy subjects were included. Indirect calorimetry (IC) was used to measure REE in both groups. The “pocket” equation (30 kcal/kg) and the Harris‐Benedict equation, with correction factors of 1.3 (activity) and 1.1 (injury), were employed for assessment of the estimated total energy expenditure (TEE). Statistics included Mann‐Whitney and paired t tests, Bland Altman analysis, and multivariate regression. Results: The REE of the patients (1,274.5 kcal [1,002.9–2,174.9]) was similar to that of the controls (1,445.5 kcal [1,114.5–1,762.6], not significant), even when corrected for the amount of metabolically active tissue. The pocket equation was effective in predicting the patients' TEE, with a 1.7% (32 kcal) difference being observed in comparison with the IC results corrected with the activity factor (not significant). Conclusions: The patients with digestive tract cancers showed a similar REE to that of the controls. The current formula of 30 kcal/kg is suitable for estimating the TEE of these patients.     

Energy requirements in the eighth decade of life

BACKGROUND: Knowledge of energy requirements among relatively healthy elderly is limited. OBJECTIVES: The objectives of the study were to measure total energy expenditure (TEE)-derived energy requirements in a biracial population of older adults without limitations to daily life and to test these empirical measures against national and international recommendations. DESIGN: TEE (measured by the doubly labeled water method), resting metabolic rate (RMR), activity-related energy expenditure (AEE), and body composition were measured in 288 persons aged 70-79 y selected from the Health, Aging, and Body Composition Study. RESULTS: TEE was lower in women (approximately 530 kcal/d; P < 0.0001) than in men because of the women's lower RMR and AEE. Fat-free mass explained the sex difference in RMR, but body weight failed to account for the women's lower AEE (approximately 1 kcal x kg(-1) x d(-1); P = 0.007). Blacks had lower TEE than did whites (approximately 100 kcal/d, P = 0.03), and that was explained by blacks' lower RMR. Physical activity level (TEE/RMR) did not differ significantly between sexes and races (1.70 +/- 0.23). The World Health Organization (WHO) recommendations overestimated TEE by 10 +/- 15% (P < 0.0001) in women but not in men, and the dietary reference intakes (DRIs) were accurate to 0 +/- 14% (P = 0.1). Both WHO and DRI recommendations are based on an underestimated physical activity level, and WHO recommendations are based on overestimated RMR. CONCLUSIONS: This study of well-functioning older adults confirms the racial difference in energy metabolism and supports the use of the 2002 DRIs. Because the DRIs and WHO recommendations underestimated PAL, new predictive equations of energy requirements are proposed.     

Is the ArteACC index a valid indicator of free-living physical activity in adolescents?

OBJECTIVE: The principal aim of this study was to validate a proposed new index of physical activity, the activity-related time equivalent based on accelerometry (ArteACC), in adolescents. A secondary aim was to develop regression equations for prediction of total energy expenditure (TEE) and activity energy expenditure [AEE = 0.9 x TEE - resting metabolic rate (RMR)]. RESEARCH METHODS AND PROCEDURES: RMR and energy expenditure (EE) under standardized exercises were measured by indirect calorimetry in 36 adolescents (14 to 19 years old). TEE was measured by the doubly labeled water method, and physical activity was assessed simultaneously with an accelerometer for 14 days. AEE, AEE in relation to body weight (AEE per kilogram), and activity-related time equivalent based on energy expenditure (ArteEE = AEE/[EE reference activity - RMR]) were calculated from laboratory and free-living EE data. ArteACC was calculated as total activity counts/activity counts of reference activity. RESULTS: ArteACC was significantly related to AEE per kilogram (r = 0.57; p < 0.0001) and ArteEE (r = 0.68; p < 0.001). The absolute amount of time (minutes per day) spent in physical activity was significantly lower when calculated from ArteACC than from ArteEE (p < 0.001). TEE was significantly influenced by RMR, sex, and ArteACC (r(2) = 0.89). AEE was significantly influenced by sex and ArteACC (r(2) = 0.59). DISCUSSION: Despite an absolute difference between the two indexes, ArteEE and ArteACC, ArteACC seems to be a valid indicator of free-living physical activity. It contributed significantly, by 3.3% and 12.5%, to the explained variations in TEE and AEE, respectively.     

A practical approach to estimate resting energy expenditure in frail elderly people

Objectives: Some prediction equations of resting energy expenditure (REE) are available and can be used in clinical wards to determine energy requirements of patients. The aim of the present study was to assess the accuracy of those equations in sick elderly patients, using the Bland & Altman methods with our database of 187 REE measurements.Design: The 3 equations tested were Harris & Benedict equation of 1919, WHO/FAO/UNU equation of 1985 and Fredrix et al. equation of 1990. In addition, three models developed from the present data were tested.Results: The present study shows that the Fredrix et al equation gave an accurate prediction of REE without significant bias along the whole range of REE. It also shows that under-weight sick elderly patients (BMI ≤ 21 kg/m²) had a greater weight-adjusted REE than their normal weight counterparts.Conclusion: A simple formula using a factor multiplying body weight, i.e. 22 kcal/kg/d in under-weight and 19 kcal/kg/d in normal weight sick elderly was accurate to predicting REE and bias was not influenced by the level of REE. This model included half of the group in the range of ±10% of the difference between predicted REE and measured REE, but the confidence interval of the bias was ±400 kcal/d. Conversely, the Harris & Benedict and WHO formulae did accurately predict REE.     

Prediction of resting energy expenditure in a large population of obese children

BACKGROUND: Recommendations for energy intake in obese children rely on accurate methods for measuring energy expenditure that cannot be assessed systematically. OBJECTIVE: The aim was to establish and validate new equations for predicting resting energy expenditure (REE), specifically in obese children. DESIGN: REE (indirect calorimetry) and body composition (bioelectrical impedance analysis) were measured in 752 obese subjects aged 3-18 y. The first cohort (n=471) was used to establish predictive equations, the second (and independent) cohort (n=211) was used to validate these equations, and the third cohort, a follow-up group of children who lost weight (n=70), was used to examine predictive REE in the postobese period. REE values predicted with the use of various published equations and the new established equation were compared with measured REE by using the Bland-Altman method and Student's t tests. RESULTS: In cohort 1, significant determinants of the new prediction equations were fat-free mass in boys (model R2=0.79) and age and fat-free mass in girls (model R2=0.76). External validation conducted by using the Bland-Altman method and Student's t tests, in cohort 2, showed no significant difference between measured REE and predicted REE with the new equation. When already published equations were applied, systematical bias appeared with all published equations except for that of the World Health Organization. In cohort 3, the children who lost weight, almost all equations significantly underestimated REE. CONCLUSIONS: These new predictive equations allow clinicians to estimate REE in an obese pediatric population with sufficient and acceptable accuracy. This estimation may be a strong basis for energy recommendations in childhood obesity.     

Energy balance in cystic fibrosis when stable and during a respiratory exacerbation

Background & aims: Undernutrition is common in young adult patients with cystic fibrosis (CF) and implies an imbalance between energy intake and total energy expenditure (TEE). The aim of this study was to measure energy intake and TEE expenditure in a group of patients when they were clinically stable at home and during an exacerbation of respiratory symptoms when they were in hospital receiving intravenous antibiotics.Methods: Eleven patients aged between 15 and 40 years with moderate respiratory disease, mean FEV₁ 51.4% predicted took part. An exacerbation was defined as>15% decrease in FEV₁, an increase in sputum production and a decision to treat in hospital with intravenous antibiotics. Resting energy expenditure (REE) was measured using indirect calorimetry and energy intake by 3 day food diaries. TEE expenditure was measured using 24 h heart rate and doubly isotopically labelled water.Results: REE was higher at the beginning of an exacerbation than the end, P<0.05. There was no significant difference in TEE during the stable period compared to the exacerbation 10.53(2.39) MJ/day compared to 8.77(1.59) MJ/day using doubly isotopically labelled water. There was no difference in energy intake during the exacerbation compared to the stable period, 11.19(2.31) MJ/day compared to11.77(2.30) MJ/day.Conclusions: There was no difference in TEE and energy intake when patients were unwell in hospital compared to when they were stable at home despite an increase in REE.     

Estimation of Resting Energy Expenditure: Validation of Previous and New Predictive Equations in Obese Children and Adolescents

Objective: Accurate estimation of resting energy expenditure (REE) in childrenand adolescents is important to establish estimated energy requirements. The aim of the present study was to measure REE in obese children and adolescents by indirect calorimetry method, compare these values with REE values estimated by equations, and develop the most appropriate equation for this group.

Methods: One hundred and three obese children and adolescents (57 males, 46 females) between 7 and 17 years (10.6 ± 2.19 years) were recruited for the study. REE measurements of subjects were made with indirect calorimetry (COSMED, FitMatePro, Rome, Italy) and body compositions were analyzed.

Results: In females, the percentage of accurate prediction varied from 32.6 (World Health Organization [WHO]) to 43.5 (Molnar and Lazzer). The bias for equations was ?0.2% (Kim), 3.7% (Molnar), and 22.6% (Derumeaux-Burel). Kim's (266 kcal/d), Schmelzle's (267 kcal/d), and Henry's equations (268 kcal/d) had the lowest root mean square error (RMSE; respectively 266, 267, 268 kcal/d). The equation that has the highest RMSE values among female subjects was the Derumeaux-Burel equation (394 kcal/d). In males, when the Institute of Medicine (IOM) had the lowest accurate prediction value (12.3%), the highest values were found using Schmelzle's (42.1%), Henry's (43.9%), and Müller's equations (fat-free mass, FFM; 45.6%). When Kim and Müller had the smallest bias (?0.6%, 9.9%), Schmelzle's equation had the smallest RMSE (331 kcal/d). The new specific equation based on FFM was generated as follows: REE = 451.722 + (23.202 * FFM). According to Bland-Altman plots, it has been found out that the new equations are distributed randomly in both males and females.

Conclusion: Previously developed predictive equations mostly provided unaccurate and biased estimates of REE. However, the new predictive equations allow clinicians to estimate REE in an obese children and adolescents with sufficient and acceptable accuracy.     

加速度计对成人日常体力活动测量效度的研究

目的　对加速度计(CSA)测量成年人日常体力活动的效度进行验证并提出根据 CSA数据预测能量消耗的方程。方法　选取 72 名北京市居民,年龄(43.6±4.0)岁,男性 33 名,女性 39名,作为调查对象,佩带7天CSA,在同一期间采用双标水方法(DLW) 测量能量消耗,包括平均每天总能量消耗(TEE)、平均每天体力活动能量消耗(AEE)和体力活动水平(PAL)作为验证标准。结果通过CSA测量的平均每天活动计数(AC)与TEE、AEE和PAL之间均呈显著相关,偏相关系数 r 分别为0.31、0.30、0.26(P<0.05)。逐步多元回归分析表明,影响TEE的因素包括去脂体重或体重指数、AC(R2=0.52~0.70),影响AEE的因素包括AC、性别和去脂体重(R2=0.25~0.32)。结论　CSA能准确测量中国成年人日常体力活动模式,AC可以解释TEE和AEE的变异。     

Measured versus predicted energy expenditure in children with inactive Crohn's disease

INTRODUCTION: The aim of the study was to assess if the estimated average requirements for energy for normal children (EAR) and the Schofield equation could reliably predict energy requirements in children with inactive Crohn's disease (CD). METHODS: Twenty-three children with inactive CD were studied, median age 14.3 years (range 7.8-16.9). Resting energy expenditure (REE) was measured by indirect calorimetry and compared with that predicted using the Schofield equation (BMR). Total energy expenditure (TEE) was measured using REE and a 3-day activity diary and compared with EAR. RESULTS: REE ranged from 79% to 136% of BMR. Mean REE was not significantly greater than mean BMR (P=0.25 2-tailed t-test). TEE ranged from 72% to 163% of estimated average requirements for energy for children of that weight (EARw). EARw tended to underestimate TEE in large children and overestimate TEE in small children (Bland-Altman plot R=0.5, P=0.002). EARw was a poor predictor of TEE (R=0.35, P=0.1). EAR underestimated energy requirements by >500 kcal/day in 40% of the children. CONCLUSIONS: The Schofield equation and EAR are unreliable methods of predicting total energy requirements in children with inactive CD with a significant potential to underestimate energy needs. When energy requirements were greater than EAR it was due to physical activity and body habitus rather than raised REE.     

Energy expenditure and motor activity in rats receiving total parenteral nutrition

Rats with intravascular catheters connected to infusion systems are frequently used in the investigation of nutritional and metabolic problems. Although the animal is often referred to as "unrestrained," there is no information on the effect of the catheter assembly or total parenteral nutrition (TPN) on total (TEE), activity (AEE), and resting (REE) energy expenditure (TEE = REE + AEE). Male Fischer 344 rats were studied in an analytical respiration calorimeter. Normal unoperated rats, aseptically catheterized orally fed rats from postoperative day 1 to 7, and TPN rats were studied. Orally fed catheterized rats had weight loss, negative nitrogen balance, negative energy balance, elevated REE, and normal AEE during the first 4 postoperative days. Their weight gain, positive nitrogen balance, AEE, and REE were almost identical to those of normal rats over postoperative days 5 through 7. REE and AEE in TPN rats were similar to values in normal rats. These data indicate that catheter operation and TPN cause no abnormality in AEE and REE if adequate time is allowed for recovery from catheter operation and strict attention is given to asepsis.     

Predictive Equations Underestimate Resting Energy Expenditure in Female Adolescents with Phenylketonuria

Resting energy expenditure (REE) is often used to estimate total energy needs. The Schofield equation based on weight and height has been reported to underestimate REE in female children with phenylketonuria (PKU). The objective of this observational, cross-sectional study was to evaluate the agreement of measured REE with predicted REE for female adolescents with PKU. A total of 36 females (aged 11.5 to 18.7 years) with PKU attending Emory University's Metabolic Camp (June 2002 to June 2008) underwent indirect calorimetry. Measured REE was compared to six predictive equations using paired Student's t tests, regression-based analysis, and assessment of clinical accuracy. The differences between measured and predicted REE were modeled against clinical parameters to determine whether a relationship existed. All six selected equations significantly under predicted measured REE (P<0.005). The Schofield equation based on weight had the greatest level of agreement, with the lowest mean prediction bias (144 kcal) and highest concordance correlation coefficient (0.626). However, the Schofield equation based on weight lacked clinical accuracy, predicting measured REE within ±10% in only 14 of 36 participants. Clinical parameters were not associated with bias for any of the equations. Predictive equations underestimated measured REE in this group of female adolescents with PKU. Currently, there is no accurate and precise alternative for indirect calorimetry in this population.     

Racial differences in energy expenditure and aerobic fitness in premenopausal women

BACKGROUND: Aerobic fitness, or maximal oxygen uptake (f1.gif" BORDER="0">O(2)max), and energy expenditure (EE) may be lower in African Americans than in whites. OBJECTIVE: The objective of this study was to compare sleeping EE (SEE), resting EE (REE), free-living total EE (TEE), and f1.gif" BORDER="0">O(2)max in African American and white women after adjustment for body composition and free-living activity-related energy expenditure (AEE). DESIGN: Eighteen African American and 17 white premenopausal women were matched for weight, percentage body fat, and age. SEE and REE were measured in a room calorimeter and f1.gif" BORDER="0">O(2)max was measured on a treadmill. Fat-free mass (FFM) and fat mass (FM) (4-compartment model), AEE (doubly labeled water and SEE), and regional lean tissue (dual-energy X-ray absorptiometry) were used as adjustment variables in SEE, REE, TEE, and f1.gif" BORDER="0">O(2)max comparisons. RESULTS: The African American women had significantly more limb lean tissue and significantly less trunk lean tissue than did the white women. The African American women also had significantly lower SEE (6.9%), REE (7.5%), TEE (9.6%), and f1.gif" BORDER="0">O(2)max (13.4%) than did the white women. Racial differences persisted after adjustment for f1.gif" BORDER="0">O(2)max, AEE, FFM, and limb lean tissue but disappeared after adjustment for trunk lean tissue. The f1.gif" BORDER="0">O(2)max difference was independent of all body-composition variables and of AEE. CONCLUSIONS: African American women had lower aerobic fitness than did white women, independent of differences in lean tissue or AEE. Diminished racial differences in SEE, REE, and TEE after adjustment for trunk lean tissue suggest that low EE in African American women is mediated by low volumes of metabolically active organ mass.     

Predictive Equations Are Inaccurate in the Estimation of the Resting Energy Expenditure of Children With End‐Stage Liver Disease

Background and Objectives: Malnutrition is common in children with end‐stage liver disease (ESLD) and is associated with increased morbidity and mortality. The inability to accurately estimate energy needs of these patients may contribute to their poor nutrition status. In clinical practice, predictive equations are used to calculate resting energy expenditure (cREE). The objective of this study is to assess the accuracy of commonly used equations in pediatric patients with ESLD. Methods: Retrospective study performed at the Hospital for Sick Children. Clinical, laboratory, and indirect calorimetry data from children listed for liver transplant between February 2013 and December 2014 were reviewed. Calorimetry results were compared with cREE estimated using the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU), Schofield [weight], and Schofield [weight and height] equations. Results: Forty‐five patients were included in this study. The median age was 9 months, and the most common indication for transplantation was biliary atresia (64%). The Schofield [weight and height], FAO/WHO/UNU, and Schofield [weight] equations were compared with indirect calorimetry and found to have a mean (SD) difference of 48.8 (344.0), 59.3 (229.8), and 206.5 (502.6) kcal/d, respectively. The FAO/WHO/UNU, Schofield [weight], and Schofield [weight and height] equations introduced a mean error of 21%, 38%, and 76%, respectively. The FAO/WHO/UNU equation tended to underestimate, whereas the Schofield equations overestimated the REE. Conclusions: Commonly used predictive equations perform poorly in infants and young children with ESLD. Indirect calorimetry should be used when available to guide energy provision, particularly in children who are already malnourished.     

Measured energy expenditure of tube-fed patients with severe neurodevelopmental disabilities

OBJECTIVE: To determine measured resting energy expenditure (REE) of nonambulatory tube-fed patients with severe neurological neurodevelopmental disabilities. METHODS: Twenty patients were prospectively studied. Only steady state indirect calorimetry measurements were taken. All measurements were conducted using a canopy system. Nutritional needs were met entirely by enteral feedings via a permanent ostomy. RESULTS: REE was widely distributed from 16 kcals/kg/day to 39 kcals/kg/day. The mean REE (888+/-176 kcals/day) of the patients was significantly (p<0.01) lower than predicted as estimated by the Harris-Benedict equations (1081+/-155 kcals/day) and World Health Organization equations (1194+/-167 kcals/day). Fat-free mass (FFM) was the best parameter for predicting REE. Two predictive equations were developed that are not significantly biased and more precise (< or =15% error) than conventional predictive formulas. CONCLUSION: Conventional formulas for estimating energy expenditure are inaccurate and generally overestimate measured energy expenditure of nonambulatory patients with severe developmental disabilities.