Resting energy expenditure in children and adolescents: agreement between calorimetry and prediction equations

Validade da equação de Henry e Rees que estima a taxa metabólica de repouso em adolescentes masculinos

OBJETIVO: Analisar a validade da equação de predição da taxa metabólica de repouso proposta por Henry e Rees (1991) em adolescentes do sexo masculino. MÉTODOS: Estudo transversal, com amostra de conveniência constituída de 52 meninos, entre dez e 17 anos, sendo mensuradas a massa corporal e a calorimetria indireta. A massa corporal foi substituída na equação de Henry e Rees para determinar a taxa metabólica de repouso predita. A calorimetria indireta foi determinada pelos valores do consumo de O2 e produção de CO2, e usada na equação de Weir (1949), considerada método padrão para o cálculo da taxa metabólica de repouso. Todas as medidas foram realizadas pela manhã, com o indivíduo em jejum de seis horas, em posição supina e em repouso muscular. Realizaram-se os seguintes procedimentos estatísticos: teste t pareado; erro constante (com diferença aceita entre as médias <5%) e, para análise da concordância entre os dois métodos, o procedimento gráfico de Bland e Altman. RESULTADOS: A equação proposta por Henry e Rees não apresentou diferença significativa em relação ao método padrão, assim como o erro constante entre as médias foi <5%. Porém, a análise gráfica de Bland e Altman revelou que não há concordância entre a equação e o método padrão. CONCLUSÕES: A equação de Henry e Rees deve ser utilizada com prudência no cálculo da taxa metabólica de respouso para adolescentes com características similares as do grupo estudado.

Dietary intakes assessed by 24-h recalls in peri-urban African adolescents: validity of energy intake compared with estimated energy expenditure

BACKGROUND/OBJECTIVE

The objective of this study is to determine the relative validity of reported energy intake (EI) derived from multiple 24-h recalls against estimated energy expenditure (EE(est)). Basal metabolic rate (BMR) equations and physical activity factors were incorporated to calculate EE(est).

SUBJECTS/METHODS

This analysis was nested in the multidisciplinary PhysicaL Activity in the Young study with a prospective study design. Peri-urban black South African adolescents were investigated in a subsample of 131 learners (87 girls and 44 boys) from the parent study sample of 369 (211 girls and 158 boys) who had all measurements taken. Pearson correlation coefficients and Bland-Altman plots were calculated to identify the most accurate published equations to estimate BMR (P<0.05 statistically significant). EE(est) was estimated using BMR equations and estimated physical activity factors derived from Previous Day Physical Activity Recall questionnaires. After calculation of EE(est), the relative validity of reported energy intake (EI(rep)) derived from multiple 24-h recalls was tested for three data subsets using Pearson correlation coefficients. Goldberg's formula identified cut points (CPs) for under and over reporting of EI.

RESULTS

Pearson correlation coefficients between calculated BMRs ranged from 0.97 to 0.99. Bland-Altman analyses showed acceptable agreement (two equations for each gender). One equation for each gender was used to calculate EE(est). Pearson correlation coefficients between EI(rep) and EE(est) for three data sets were weak, indicating poor agreement. CPs for physical activity groups showed under reporting in 87% boys and 95% girls.

CONCLUSION

The 24-h recalls measured at five measurements over 2 years offered poor validity between EI(rep) and EE(est).

Gasto energético em adolescentes asmáticos com excesso de peso: calorimetria indireta e equações de predição

OBJETIVO: Comparar o gasto energético medido por calorimetria indireta com o estimado por equações de predição entre adolescentes asmáticos e não asmáticos. MÉTODOS: Trata-se de estudo transversal com 69 adolescentes de 10 a 18 anos. Foram comparados três grupos pareados (asmáticos com excesso de peso, asmáticos eutróficos e não asmáticos com excesso de peso). Para avaliação nutricional utilizaram-se medidas antropométricas e de composição corporal. O gasto energético foi medido por calorimetria indireta e estimado por fórmulas de predição. RESULTADOS: Cada grupo foi composto por 23 adolescentes, dos quais 10 do sexo feminino, com média de idade de M=12,4, DP=2,4 anos. O gasto energético de repouso, pela calorimetria indireta nos asmáticos com excesso de peso, foi de M=1550,2, DP=547,2kcal/dia; nos asmáticos eutróficos, M=1540,8, DP=544,2kcal/dia; e nos não asmáticos com excesso de peso, M=1697,2, DP=379,8kcal/dia, com resultado semelhante entre os grupos, mesmo quando ajustado pela massa magra e massa gorda (f=0,186; p=0,831). Obtiveram-se achados semelhantes entre o gasto energético medido pela calorimetria indireta e o estimado pelas fórmulas de predição, com exceção da fórmula de Harris-Benedict, que subestimou o gasto energético nos asmáticos eutróficos e nos não asmáticos com excesso de peso. CONCLUSÃO: O gasto energético de repouso não foi estatisticamente diferente entre os grupos asmáticos e não asmáticos, mesmo quando ajustado pela massa magra e massa gorda. Para os três grupos, as equações de predição são úteis para estimar o gasto energético de repouso e o gasto energético total.

Variable dietary management of methylmalonic acidemia: metabolic and energetic correlations

BACKGROUND

Isolated methylmalonic acidemia (MMA) is managed by dietary protein restriction and medical food supplementation. Resting energy expenditure (REE) can be depressed in affected individuals for undefined reasons.

OBJECTIVE

The objective was to document the spectrum of nutritional approaches used to treat patients with MMA, measure REE, and analyze the dependence of REE on body composition, biochemical, and nutritional variables.

DESIGN

Twenty-nine patients with isolated MMA (22 mut, 5 cblA, 2 cblB; 15 males, 14 females; age range: 2-35 y) underwent evaluation. REE was measured with open-circuit calorimetry and compared with predicted values by using age-appropriate equations.

RESULTS

Nutritional regimens were as follows: protein restriction with medical food (n = 17 of 29), protein restriction with medical food and supplemental isoleucine or valine (n = 5 of 29), or the use of natural protein alone for dietary needs (n = 7 of 29). Most mut patients had short stature and higher percentage fat mass compared with reference controls. Measured REE decreased to 74 ± 13.6% of predicted (P < 0.001) in the ≤ 18-y group (n = 22) and to 83 ± 11.1% (P = 0.004) in patients aged >18 y (n = 7). Linear regression modeling suggested that age (P = 0.001), creatinine clearance (P = 0.01), and height z score (P = 0.04) accounted for part of the variance of measured REE per kilogram of fat-free mass (model R² = 0.66, P < 0.0001).

CONCLUSIONS

There is wide variation in the dietary treatment of MMA. Standard predictive equations overestimate REE in this population primarily due to their altered body composition and decreased renal function. Defining actual energy needs will help optimize nutrition and protect individuals from overfeeding. This trial is registered at clinicaltrials.gov as NCT00078078.

The mass-specific energy cost of human walking is set by stature

The metabolic and mechanical requirements of walking are considered to be of fundamental importance to the health, physiological function and even the evolution of modern humans. Although walking energy expenditure and gait mechanics are clearly linked, a direct quantitative relationship has not emerged in more than a century of formal investigation. Here, on the basis of previous observations that children and smaller adult walkers expend more energy on a per kilogram basis than larger ones do, and the theory of dynamic similarity, we hypothesized that body length (or stature, Lb) explains the apparent body-size dependency of human walking economy. We measured metabolic rates and gait mechanics at six speeds from 0.4 to 1.9 m s–1 in 48 human subjects who varied by a factor of 1.5 in stature and approximately six in both age and body mass. In accordance with theoretical expectation, we found the most economical walking speeds measured (J kg–1 m–1) to be dynamically equivalent (i.e. similar U, where U=velocity2/gravity · leg length) among smaller and larger individuals. At these speeds, stride lengths were directly proportional to stature whereas the metabolic cost per stride was largely invariant (2.74±0.12 J kg–1 stride–1). The tight coupling of stature, gait mechanics and metabolic energy expenditure resulted in an inverse relationship between mass-specific transport costs and stature (Etrans/Mb∝Lb–0.95, J kg–1 m–1). We conclude that humans spanning a broad range of ages, statures and masses incur the same mass-specific metabolic cost to walk a horizontal distance equal to their stature.

Review of prediction models to estimate activity-related energy expenditure in children and adolescents

Purpose. To critically review the validity of accelerometry-based prediction models to estimate activity energy expenditure (AEE) in children and adolescents. Methods. The CINAHL, EMBASE, PsycINFO, and PubMed/MEDLINE databases were searched. Inclusion criteria were development or validation of an accelerometer-based prediction model for the estimation of AEE in healthy children or adolescents (6–18 years), criterion measure: indirect calorimetry, or doubly labelled water, and language: Dutch, English or German. Results. Nine studies were included. Median methodological quality was 5.5 ± 2.0 IR (out of a maximum 10 points). Prediction models combining heart rate and counts explained 86–91% of the variance in measured AEE. A prediction model based on a triaxial accelerometer explained 90%. Models derived during free-living explained up to 45%. Conclusions. Accelerometry-based prediction models may provide an accurate estimate of AEE in children on a group level. Best results are retrieved when the model combines accelerometer counts with heart rate or when a triaxial accelerometer is used. Future development of AEE prediction models applicable to free-living scenarios is needed.

Taxa metabólica basal em universitários: comparação entre valores medidos e preditos

OBJETIVO: Comparar a taxa metabólica basal medida por recursos de calorimetria indireta com a taxa metabólica basal estimada por equações de predição em universitários. MÉTODOS: A amostra foi constituída por 48 voluntários (23 moças e 25 rapazes) na faixa etária entre 20 e 25 anos. A taxa metabólica basal medida por calorimetria indireta foi comparada à taxa metabólica basal estimada pelas equações de predição propostas pela World Health Organization e por Henry & Rees. As informações foram analisadas mediante o teste t pareado, coeficiente de correlação intraclasse, desvio-padrão das diferenças e técnica de Bland-Altman. RESULTADOS: Não ocorreram diferenças significativas entre os valores da taxa metabólica basal medidos e estimados por ambas as equações de predição. Os coeficientes de correlação intraclasse entre os valores medidos e estimados foram significativos em linguagem estatística nos dois gêneros e mais elevados nos rapazes, e a magnitude do desvio-padrão das diferenças foi similar em ambos os gêneros. A técnica de Bland-Altman sugere comportamento de variabilidade similar entre a taxa metabólica basal medida e predita por ambas as equações, porém a taxa metabólica basal predita pela equação de Henry & Rees apresentou coincidências mais elevadas, sobretudo entre as moças. CONCLUSÃO: Mediante indicadores estatísticos mais conservadores, conclui-se que a taxa metabólica basal medida por recursos de calorimetria indireta e predita por ambas as equações não apresentam diferenças significativas. No entanto, ao considerar procedimentos estatísticos aparentemente de maior sensibilidade na detecção de eventuais diferenças entre os valores medidos e preditos, verificou-se algum comprometimento quanto à potencialidade das equações para estimar a taxa metabólica basal, apresentando viés entre 12,5% e 15,6% em comparação com a taxa metabólica basal medida por recursos de calorimetria indireta.

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.

Validation of predictive equations for resting energy expenditure in obese adolescents

BACKGROUND

When the resting energy expenditure (REE) of overweight and obese adolescents cannot be measured by indirect calorimetry, it has to be predicted with an equation.

OBJECTIVE

The aim of this study was to examine the validity of published equations for REE compared with indirect calorimetry in overweight and obese adolescents.

DESIGN

Predictive equations based on weight, height, sex, age, fat-free mass (FFM), and fat mass were compared with measured REE. REE was measured by indirect calorimetry, and body composition was measured by dual-energy X-ray absorptiometry. The accuracy of the REE equations was evaluated on the basis of the percentage of adolescents predicted within 10% of REE measured, the mean percentage difference between predicted and measured values (bias), and the root mean squared prediction error (RMSE).

RESULTS

Forty-three predictive equations (of which 12 were based on FFM) were included. Validation was based on 70 girls and 51 boys with a mean age of 14.5 y and a mean (+/-SD) body mass index SD score of 2.93 +/- 0.45. The percentage of adolescents with accurate predictions ranged from 74% to 12% depending on the equation used. The most accurate and precise equation for these adolescents was the Molnar equation (accurate predictions: 74%; bias: -1.2%; RMSE: 174 kcal/d). The often-used Schofield-weight equation for age 10-18 y was not accurate (accurate predictions: 50%; bias: +10.7%; RMSE: 276 kcal/d).

CONCLUSIONS

Indirect calorimetry remains the method of choice for REE in overweight and obese adolescents. However, the sex-specific Molnar REE prediction equation appears to be the most accurate for overweight and obese adolescents aged 12-18 y. This trial was registered at www.trialregister.nl with the Netherlands Trial Register as ISRCTN27626398.

Validação das equações que estimam a taxa metabólica de repouso em adolescentes meninas

OBJETIVOS: O objetivo deste estudo é analisar a validade das equações de predição da taxa metabólica de repouso (TMR) propostas por Harris e Benedicti (1919), Schofield (1985), WHO/FAO/UNU (1985), Henry e Rees (1991), Molnár e cols. (1995), Tverskaya e cols. (1998) e Müller e cols. (2004) em adolescentes meninas. SUJEITOS E MÉTODOS: Para tanto, avaliaram-se 51 meninas entre 10 e 17 anos, sendo mensuradas as seguintes variáveis: massa corporal, estatura, massa gorda (absoluta e percentual) e massa magra (absoluta e percentual), bem como os valores do consumo de VO2 e produção de VCO2 que foram substituídos na equação de Weir (1949) considerada, neste estudo, como método padrão da TMR. Realizaram-se os seguintes procedimentos estatísticos: teste "t" pareado (p < 0,05); erro constante (EC) com diferença menor que 5% e análise gráfica de Bland e Altman (1986). RESULTADOS: As equações propostas por Tverskaya e cols. (1998) e Müller e cols. (2004) foram as únicas que apresentaram diferenças significativas entre as médias. No entanto, somente as equações propostas por Henry e Rees (1991) e Molnár e cols. (1995) obtiveram erro constante inferior a 5%. Porém, as análises gráficas de Bland e Altman (1986) revelaram que, independentemente da equação, não há concordância entre as equações e o método padrão. CONCLUSÕES: O estudo indicou que as equações não aprovaram nos critérios estipulados e que, portanto, não possuem validade no cálculo da TMR.

Interplay between weight loss and gut microbiota composition in overweight adolescents

The aim of this study was to determine the influence of an obesity treatment program on the gut microbiota and body weight of overweight adolescents. Thirty-six adolescents (13-15 years), classified as overweight according to the International Obesity Task Force BMI criteria, were submitted to a calorie-restricted diet (10-40%) and increased physical activity (15-23 kcal/kg body weight/week) program over 10 weeks. Gut bacterial groups were analyzed by quantitative real-time PCR before and after the intervention. A group of subjects (n=23) experienced >4.0 kg weight loss and showed significant BMI (P=0.030) and BMI z-score (P=0.035) reductions after the intervention, while the other group (n=13) showed <2.0 kg weight loss. No significant differences in dietary intake were found between both groups. In the whole adolescent population, the intervention led to increased Bacteroides fragilis group (P=0.001) and Lactobacillus group (P=0.030) counts, and to decreased Clostridium coccoides group (P=0.028), Bifidobacterium longum (P=0.031), and Bifidobacterium adolescentis (P=0.044) counts. In the high weight-loss group, B. fragilis group and Lactobacillus group counts also increased (P=0.001 and P=0.007, respectively), whereas C. coccoides group and B. longum counts decreased (P=0.001 and P=0.044, respectively) after the intervention. Total bacteria, B. fragilis group and Clostridium leptum group, and Bifidobacterium catenulatum group counts were significantly higher (P<0.001-0.036) while levels of C. coccoides group, Lactobacillus group, Bifidobacterium, Bifidobacterium breve, and Bifidobacterium bifidum were significantly lower (P<0.001-0.008) in the high weight-loss group than in the low weight-loss group before and after the intervention. These findings indicate that calorie restriction and physical activity have an impact on gut microbiota composition related to body weight loss, which also seem to be influenced by the individual's microbiota.

Dietary intakes of children with Crohn's disease

Approximately 25 % of individuals with Crohn's disease (CD), a life-long relapsing-remitting disease, are diagnosed during childhood and adolescence. Symptoms of CD, including abdominal pain, nausea and diarrhoea, can lead to reduced food intake, which may negatively have an impact on nutritional status during this critical period of growth and development. The aims of the present study were to assess the growth and adequacy of dietary intakes of children with CD at Sydney Children's Hospital, Randwick, and compare with healthy controls. Sixty-three subjects aged 10-16 years were recruited, including: children with active CD (n 18), children with CD in remission (n 23) and healthy controls (n 22). Dietary intake was assessed using a FFQ and compared with current Australian recommended dietary intakes (RDI). Growth and dietary intakes were compared between groups. Subjects with active CD had lower weight and BMI Z scores than children in remission and controls. The energy intakes of children with active CD and those in remission were significantly lower than estimated energy requirements (P = 0.001 and P = 0.03 respectively). Children with active CD did not meet the RDI for Fe and their Ca intake was lower than the RDI (P = 0.04). In conclusion, the dietary intake of children with active CD was impaired, with inadequate intakes of energy, Ca and Fe. Reduced energy intakes during active disease may contribute to poor weight gain and impaired growth. Quantifying nutrient intake and ascertaining requirements for nutritional supplementation are essential components of successful management in paediatric CD.

Shifts in clostridia, bacteroides and immunoglobulin-coating fecal bacteria associated with weight loss in obese adolescents

OBJECTIVE

To evaluate the effects of a multidisciplinary obesity treatment programme on fecal microbiota composition and immunoglobulin-coating bacteria in overweight and obese adolescents and their relationship to weight loss.

DESIGN

Longitudinal intervention study based on both a calorie-restricted diet (calorie reduction=10-40%) and increased physical activity (calorie expenditure=15-23 kcal/kg body weight per week) for 10 weeks.

PARTICIPANTS

Thirty-nine overweight and obese adolescents (BMI mean 33.1 range 23.7-50.4; age mean 14.8 range, 13.0-16.0).

MEASUREMENTS

BMI, BMI z-scores and plasma biochemical parameters were measured before and after the intervention. Fecal microbiota was analyzed by fluorescent in situ hybridization. Immunoglobulin-coating bacteria were detected using fluorescent-labelled F(ab')2 antihuman IgA, IgG and IgM.

RESULTS

Reductions in Clostridium histolyticum and E. rectale-C. coccoides proportions significantly correlated with weight and BMI z-score reductions in the whole adolescent population. Proportions of C. histolyticum, C. lituseburense and E. rectale-C. coccoides dropped significantly whereas those of the Bacteroides-Prevotella group increased after the intervention in those adolescents who lost more than 4 kg. Total fecal energy was almost significantly reduced in the same group of adolescents but not in the group that lost less than 2.5 kg. IgA-coating bacterial proportions also decreased significantly in participants who lost more than 6 kg after the intervention, paralleled to reductions in C. histolyticum and E. rectale-C. coccoides populations. E. rectale-C. coccoides proportions also correlated with weight loss and BMI z-score reduction in participants whose weight loss exceeded 4 kg.

CONCLUSIONS

Specific gut bacteria and an associated IgA response were related to body weight changes in adolescents under lifestyle intervention. These results suggest interactions between diet, gut microbiota and host metabolism and immunity in obesity.

Is it necessary to measure resting energy expenditure in clinical practice in children?

We compared measured resting energy expenditure (MREE) and predicted resting energy expenditure (PREE) in 398 chronically ill children and found a wide variability for %MREE/PREE (standard deviation +/- 27.2). Bland-Altman analysis also suggested poor agreement between MREE and PREE (mean bias, 43.2 kcal; range, -645 to 1118.1 kcal). Our findings suggest that resting energy expenditure should be measured in chronically ill children.

Effect of exocrine pancreatic function on resting energy expenditure in cystic fibrosis

AIM

To prove the hypothesis that exocrine pancreatic function determines resting energy expenditure (REE) in cystic fibrosis (CF).

METHOD

Thirty-eight CF individuals, 9-34 (19.98 +/- 1.0) years, were divided into three groups: Six pancreatic sufficient patients (PS; group A), 21 pancreatic insufficient patients (PI), whose pulmonary function was comparable to that of group A (group B1) and 11 PI patients, whose pulmonary function was significantly worse than that of group A (group B2). REE was estimated by indirect calorimetry. Predicted REE was based on Schofield equations. Measured REE was expressed as % of the predicted. BMI, BMI z-scores, serum albumin, cholesterol and triglycerides levels were related to REE. Results were expressed as mean +/- standard error.

RESULTS

Groups B1 and B2 had significantly higher REE% (111.7 +/- 2.75% and 119.94 +/- 3.8, respectively) as opposed to group A (98.9 +/- 3.81%; p = 0.022 and 0.035, respectively) whose REE% was similar to that predicted. REE% between group B1 and B2 was not statistically significant. In groups A, B1 and B, mean FEV1% was 86.33 +/- 10.1%, 90.24 +/- 4.39%, 44.54 +/- 3.47%, respectively, mean BMI was 25.6 +/- 2.06, 19.48 +/- 0.64 and 20.09 +/- 8.8, respectively, BMI z-scores were 0.75 +/- 0.51, -0.52 +/- 0.24 and -1.07 +/- 0.37, respectively. Significant correlation was demonstrated between REE%, BMI z-scores and cholesterol levels in group A.

CONCLUSION

Clinically stable CF patients, who had comparable pulmonary function, exhibited increased REE% only in the presence of exocrine pancreatic insufficiency. REE% strongly correlated with BMI z-scores in pancreatic sufficiency. These findings support the hypothesis that pancreatic rather than pulmonary function may determine nutritional status as well as REE in CF.

Comparison of equations for estimating resting metabolic rate in healthy subjects over 70 years of age

INTRODUCTION

There is a lack of validation studies of formulas for estimating resting metabolic rate (RMR) in healthy subjects over 70 years of age. Indirect calorimetry allows measuring RMR (RMRm), but is time consuming and costly and therefore formula are generally used to estimate RMR (RMRe). We assessed the degree of agreement between RMRm and RMRe predicted by five popular equations: Harris-Benedict (HB), Mifflin-St Jeor (MJ), Owen (OW), World Health Organization (WHO/FAO/UNU) and Lührmann (LM) in a cohort of elderly subjects.

METHODS

In 119 healthy subjects, aged 70-98 yr, RMRm was obtained by indirect calorimetry and RMRe by the HB, MJ, OW, WHO/FAO/UNU and LM equations. Means were compared by paired t-test. The Bland and Altman method was used to assess agreement between RMRm and RMRe. Accuracy was defined as the % of individuals whose RMRe was within +/-10% of RMRm.

RESULTS

The HB showed the lowest mean RMRe-RMRm difference (-40.9 kcal/day), followed by LM (+44.8 kcal/day) and WHO/FAO/UNU (+53 kcal/day). The HB performed the best of the five equations, having 72.4% of the cases within+/-10% of RMRm. In 18.7% of male subjects and 20% of female subjects HB underestimated the measured values.

CONCLUSIONS

Large discrepancies exist between RMRm and RMRe in subjects above 70 years of age. HB performs best, but still tends to underestimate in both sexes. In order to develop more accurate equations to estimate RMR in elderly subjects it would be worthwhile to examine whether additionally specific markers of body composition should be taken into consideration.

Predictive validity of an age-specific MET equation among youth of varying body size

The purpose of this study was to cross-validate the age-specific Freedson MET equation among children and adolescents of varying body size. Sixty-seven children (41 boys; 26 girls) between 6 and 13 years completed five 3-min trials (1.6, 3.2, 4.0, 4.8, and 6.4 km h(-1)) on a motorized treadmill. During each trial, participants wore an Actigraph accelerometer while oxygen consumption was assessed by indirect calorimetry. Using the Actigraph activity counts, predicted MET values were determined with the age-specific Freedson equation and were compared with measured MET values using dependent t tests. Participants were divided into body size categories based on their calculated body surface area (BSA, m2) (small: BSA<or=0.96 m2; medium: 0.96 m2<BSA<or=1.20 m2; large: BSA>1.20 m2) to determine if body size influenced the difference between measured and predicted MET values. The measured MET value was similar to the predicted MET value at the slowest treadmill speed (1.6 km h(-1)) (2.3 vs. 2.3 METs); however, the measured MET value was lower than the predicted MET value at the remaining speeds (3.2, 4.0, 4.8, and 6.4 km h(-1)) (P<0.001). With the exception of the fastest treadmill speed (6.4 km h(-1)), the mean difference between the measured and predicted MET values was greater between the two smaller BSA categories compared to the largest BSA category. The results suggest that the age-specific Freedson child equation significantly overestimates energy expenditure (METs) during locomotor speeds between 3.2 and 6.4 km h(-1). This effect was primary observed among relatively smaller children.

Avaliação da eficiência da nutrição parenteral quanto à oferta de energia em pacientes oncológicos pediátricos

OBJETIVO: Avaliar a eficiência da nutrição parenteral administrada a pacientes oncológicos pediátricos quanto à oferta de energia, indicações e principais dificuldades no procedimento. MÉTODOS: Estudo observacional descritivo, realizado entre julho de 2003 e julho de 2004 no Instituto de Oncologia Pediátrica da Universidade Federal de São Paulo. Critérios de inclusão: pacientes com câncer recebendo nutrição parenteral nas unidades de internação. A análise da adequação energética foi efetuada usando-se equações preditivas para o cálculo do gasto energético basal ajustado para a progressão inicial. RESULTADOS: Foram 41 episódios de nutrição parenteral de, 1.016, internações (4%): 54% do sexo masculino, com mediana de uso de 10 dias (1-51). Demonstrou-se que em 56% dos episódios não se atingiu o gasto energético basal ajustado; 26% ficaram entre 100% e 120% e 18% acima de 120%. A média do gasto energético basal ajustado foi 106%, com desvio-padrão de 38% e a mediana 96%. Os motivos associados às dificuldades para atingir o gasto energético basal foram intolerância metabólica, via de nutrição parenteral não exclusiva, suspensão ou interrupção da sua administração, prescrição sem discussão com nutricionista e uso de via periférica. A principal indicação foi por toxicidade gastrintestinal. O volume desprezado de nutrição parenteral demonstrou-se superior a 10% em 17 de 35 episódios (49%). Proteção contra luz ambiente (capa), avaliada em 19 pacientes durante os dias da administração, detectou ausência em 37 de 315 dias (12%). CONCLUSÃO: A oferta de energia não contemplou as necessidades de alta porcentagem de pacientes, principalmente devido à gravidade do quadro clínico, às interrupções e ao uso de via não exclusiva, reduzindo o período disponível para administração da nutrição. A eficiência dos procedimentos por atuação de equipe multidisciplinar poderia reduzir o prejuízo, garantindo uma oferta mais adequada, aumentando os benefícios da nutrição parenteral.

Experimental demonstration of human weight homeostasis: implications for understanding obesity

The existence of a set-point for homeostatic control of human body weight is uncertain. To investigate its existence, technically difficult determinations of energy expenditure must be performed: this has resulted in contradictory reports. The present study was performed with new methods in two stages (77 and 133d respectively). Two healthy male subjects with rigorously controlled physical activity ingested three standardized diets of processed foods from the same manufacturer. Hypo-, iso- and hyperenergetic diets containing 6255kJ (1494kcal), 10073kJ (2406kcal) and 13791kJ (3294kcal) respectively were ingested during alternate periods; changes in body weight were measured. A new index of energy expenditure was calculated as the amount of weight lost in an 8h overnight period (WL8H). A digital scale was used in stage 1 and a mechanical scale in stage 2. The change in body weight in response to the isoenergetic diet differed according to the circumstances. In basal conditions, it was associated with weight stability. After weight loss from energy restriction, the isoenergetic diet led to weight gain. After weight gain from overeating, it led to weight loss. Diets of higher energy content were associated with greater WL8H (F>20; P<0·0001 for both subjects). Measurement variability was lower using a mechanical scale. The present study demonstrates the existence of a homeostatic control of human weight and describes a new index of energy expenditure measured in weight units. It also demonstrates that strict dietary supervision for months is possible. Investigation of the human body weight set-point is vital in understanding obesity.

How accurate are predictive formulas calculating energy expenditure in adolescent patients with anorexia nervosa?

BACKGROUND & AIMS

To compare resting energy expenditure, measured by indirect calorimetry, to values estimated by different predictive formulas in adolescent patients with anorexia nervosa.

METHODS

We studied 22 female in-patients with a mean age of 14.7 years (SD 1.2). Resting energy expenditure was measured by indirect calorimetry (Deltatrac II MBM-200). We compared measured resting energy expenditure to values estimated by several predictive formulas [Fleisch, Harris-Benedict, FAO, Schofield-HW, Schebendach] using the intraclass correlation coefficient and the Bland-Altman method.

RESULTS

Body mass index increased significantly (P<0.001). Measured resting energy expenditure increased during hospitalization (P<0.05). All formulas overestimated resting energy expenditure with respect to indirect calorimetry except the Schebendach formula. The intraclass correlation between indirect calorimetry and the formulas were poor (0.09-0.20). We observed a poor clinical agreement (Bland-Altman).

CONCLUSIONS

Body mass index and resting energy expenditure increased during hospitalization. The majority of the predictive formulas overestimate resting energy expenditure in adolescent patients with anorexia nervosa. Therefore, indirect calorimetry may be a very useful tool for calculating caloric requirements in these patients.

Effects of sibutramine on thermogenesis in obese patients assessed via immersion calorimetry

Glucose utilization studies show that sibutramine-induced thermogenesis is mediated via selective sympathetic activation of brown adipose tissue. The goal of the present study was to use a new calorimetry method in which resting metabolic rate is enhanced to evaluate the effects of sibutramine treatment on thermogenesis. Sixty obese women were included in the study. Subjects were divided into 2 equal groups-the placebo and sibutramine treatment groups. The sibutramine group was given sibutramine 10 mg daily for 12 wk. At baseline and at the end of the 12-wk treatment period, thermogenic measurements were taken with the use of water immersion calorimetry. Subjects were examined at weeks 4, 8, and 12 of treatment to identify adverse effects. Body mass index, measured at 31.5+/-2.05 kg/m2 in the placebo group, decreased to 30.4+/-2.94 kg/m(2) after 12 wk (P=.07). In the sibutramine group, it decreased from 33.5+/-4.1 kg/m(2) to 30.9+/-4.8 kg/m(2) (P<.05). In the sibutramine group, mean thermogenic response changed from a baseline value of 1.27+/-0.29 kcal/kg/h to 1.44+/-0.13 kcal/kg/h after 12 wk of treatment. In the placebo group, the baseline value was 1.56+/-0.27 kcal/kg/h; it changed to 1.33+/-0.36 kcal/kg/h at the end of 12 wk. The findings of this study suggest that sibutramine treatment promotes thermogenesis, thus facilitating weight loss. Calorimetry enhances resting metabolism through more efficient heat transfer from the body.

Resting energy expenditure in cystic fibrosis as an indicator of disease severity

BACKGROUND

An imbalance of energy expenditure has been reported in Cystic Fibrosis (CF). High-energy diets, in combination with pancreatic enzymes, do not always compensate for energy requirements. The aim of this study was to investigate the relation between Resting Energy Expenditure (REE) and disease severity in CF.

METHODS

REE was measured with indirect calorimetry in a group of 38 clinically stable CF patients (32 with pancreatic insufficiency and 6 with pancreatic sufficiency). Correlations between REE and pulmonary function as well as clinical status were studied.

RESULTS

Increased REE expressed as a percentage of predicted (REE%) was demonstrated in pancreatic insufficient CF patients (PI) (113.3+/-2.5%), as compared to pancreatic sufficient (98.9+/-2.5%) and healthy subjects. The elevated REE% in the PI group was not affected by gender and exhibited a strong correlation with the clinical status of the patients (r=-0.641).

CONCLUSIONS

Our data analysis supports the argument that the percentage of predicted REE is an objective indicator of disease severity and progression as well as energy requirements in the assessment of CF patients.

Comparison of resting energy expenditure in bronchopulmonary dysplasia to predicted equation

OBJECTIVE

Children with bronchopulmonary dysplasia (BPD) often suffer from growth failure because of disturbances in energy balance with an increase of resting energy expenditure (REE). Evaluation of REE is a useful tool for nutritional management. Indirect calorimetry is an elective method for measuring REE, but it is time consuming and requires rigorous procedure. The objective of this study was to test accuracy of prediction equation to evaluate REE in BPD children.

PATIENTS AND METHODS

Fifty-two children aged 4-10 years with BPD (30 boys and 22 girls) and 30 healthy lean children (20 boys and 10 girls) were enrolled. In this study, indirect calorimetry was compared to four prediction equations (Schoffield-W, Schoffield-HW, Harris-Benedict and Food and Agriculture Organization equation) using Bland-Altman pair wise comparison.

RESULTS

The Harris-Benedict equation was the best equation to predict REE in children with BPD, and Schoffield-W was the best in healthy children. For the children with chronic lung disease of prematurity the Harris-Benedict equation showed the lowest mean predicted REE-REE measured by indirect calorimetry difference (difference = 15 kcal/day; limits of agreement -266 and 236 kcal/day; 95% confidence interval for the bias -207 to 177 kcal/day), and graphically, the best agreement. For the group of healthy children, it was the Schofield-W equation (-2.9 kcal/day; limits of agreement -275 and 269 kcal/day; 95% confidence interval for the bias -171 to 165 kcal/day), and graphically, the best agreement.

CONCLUSION

Differences in prediction equation are minimal compared to calorimetry. Prediction equation could be useful in the management of children with BPD.

Resting energy expenditure in severely burned children: Analysis of agreement between indirect calorimetry and prediction equations using the Bland–Altman method

INTRODUCTION

Knowledge of a child's resting energy expenditure (REE) is essential in optimizing nutritional support for severely burned children. The provision of adequate nutritional support is vital in order to avoid the consequences of malnutrition or overfeeding. Nutritional requirements for severely burned children are often based on equations for estimates of REE. The accuracy of the predictive equations of REE has been questioned and many authors have advocated the measurement of REE. This study tests the hypothesis that estimates of REE vary significantly from measured REE (MREE) in a population of severely burned children, and are not accurate for determining nutritional requirements.

METHODS

In 91 severely burned children aged between 3 and 18 years, REE was measured by indirect calorimetry (MREE) at the height of the hypermetabolic response and compared with predicted equations (PREE) from the Food and Agriculture/World Health Organization/United Nations University (FAO/WHO/UNU), Schofield-HW and Harris-Benedict. Agreement between indirect calorimetry and predicted equations was assessed following the Bland-Altman method.

RESULTS

In the entire cohort group, predicted REE from all three equations were significantly lower compared to MREE (p<0.05). There was poor agreement between the MREE and predicted using all three equations. The Schofield-HW equation showed the lowest mean MREE-PREE difference: 635+/-526 kcal/day (limits of agreement -608 and 1878 kcal/day; 95% confidence interval for the bias 525-745 kcal/day). Additionally, all three equations under predicted REE and were not significantly different from one another (p=0.98).

CONCLUSIONS

Until more accurate predicted equations are developed, we recommend indirect calorimetry measurements for determining resting energy expenditure in severely burned children.

An environmental approach to obesity prevention in children: Medical College of Georgia FitKid Project year 1 results

OBJECTIVE

To test the hypothesis that third grade children (mean age = 8.7, SD = 0.5) who attended an 8-month after-school program would exhibit favorable changes in body composition, cardiovascular fitness, blood pressure, total cholesterol, and high-density lipoprotein-cholesterol compared with children in control condition.

RESEARCH METHODS AND PROCEDURES

Subjects were 61% African-American, 31% white, and 8% other racial background from 18 public schools. Sixty-eight percent were eligible for free or reduced price lunch. Percentage body fat and bone mineral density were assessed by DXA, cardiovascular fitness by heart rate response to a step test, resting blood pressure with a Dinamap, and non-fasting total cholesterol and high-density lipoprotein-cholesterol by finger stick. Data pre- and post-intervention were available for 447 children. Children in the nine intervention schools who attended at least 40% of the after-school sessions were compared with control subjects.

RESULTS

Compared with the control subjects and after controlling for race, sex, free/reduced price lunch status, and school-level covariates, youths in the intervention group showed a relative reduction of percentage body fat [-0.76 (95% confidence interval (CI), -1.42, -0.09)], a greater relative gain in bone mineral density [0.008 (95% CI, 0.001, 0.005)], and a greater relative reduction in heart rate response to the step test [-4.4 (95% CI, -8.2, 0.6)]. The other outcome variables showed non-significant trends in favor of the intervention subjects.

DISCUSSION

These results are promising in light of the potential impact on the emerging childhood obesity epidemic. The Medical College of Georgia FitKid Project has the potential to be institutionalized because it is built on the existing infrastructure in most public schools in the U.S.

Relação entre diferentes índices de atividade física e preditores de adiposidade em adolescentes de ambos os sexos

OBJETIVO: Determinar a relação entre diferentes índices de atividade física e preditores de adiposidade em adolescentes de ambos os sexos. MÉTODOS: Foram avaliadas 111 crianças (57 meninos e 54 meninas), com idade média de 11,62 ± 0,72. Como preditores de adiposidade foram determinados o IMC, percentagem de gordura corporal e a relação cintura/quadril (RCQ). Quanto aos indicadores de atividade física, calcularam-se o gasto energético total (GET), nível de atividade física habitual (NAFH), nível de atividade física (NAF) e gasto energético com atividade física (GEat) através do questionário de Bouchard e, para a taxa metabólica basal (TMB), a equação de Schofield-HW. RESULTADOS: A amostra apresentou diferenças significativas entre os sexos para idade, % de gordura corporal, RCQ, NAFH, NAF, TMB com p < 0,05. Para os meninos o GET, NAF, TMB e GEat apresentaram correlação significativa com o IMC (r = 0,86; r = 0,70; r = 0,91; r = 0,78) e % de gordura (r = 0,78; r = 0,61; r = 0,90; r = 0,70) com p < 0,01, respectivamente, e o GET, TMB, GEat apresentaram correlação significativa com o RCQ (r = 0,28; r = 0,45 e r = 0,28) com p < 0,05. Para as meninas o GET, NAF, TMB, GEat apresentaram valores significativos com o IMC (r = 0,86; r = 0,82; r = 0,78; r = 0,85); em % de gordura todos os indicadores GET, NAFH, NAF, TMB e GEat foram significativos (r = 0,73; r = -0,29; r = 0,66; r = 0,74; r = 0,70) com p < 0,05. CONCLUSÃO: Os diferentes indicadores de nível de atividade física apresentaram significativa correlação com os preditores de adiposidade com exceção do RCQ para as meninas. O aumento da massa corporal demonstrou relação significância com o aumento do dispêndio energético em função da maior necessidade de energia para movimentar o corpo.

Caloric requirement for refeeding inpatients with anorexia nervosa: the contribution of anxiety exercise, and cigarette smoking

BACKGROUND

Refeeding inpatients with anorexia nervosa (AN) is costly, stressful, and can precipitate the refeeding syndrome. Caloric intake is usually increased gradually from a low starting point until a steady weight gain is achieved. There is no reliable equation that predicts the number of calories required for a weight gain. It was our clinical suspicion that anxiety, exercise, and cigarette smoking might increase the caloric need for refeeding.

METHOD

We conducted an observational cohort study of 17 females with AN admitted to an inpatient eating disorder unit for refeeding. We estimated the energy intake by observation, the caloric expenditure due to exercise with a triaxial accelerometer, the number of cigarettes smoked by history, and the anxiety by the Beck Anxiety Inventory (BAI).

RESULTS

Neither anxiety, exercise, or cigarette smoking predicted the caloric requirement for refeeding, individually or in combination.

DISCUSSION

Our data suggest that the caloric requirement for weight gain during refeeding is not predicted by the patient's anxiety, exercise or smoking habits. The standard methods of estimating caloric requirements for refeeding remain indirect calorimetry and previous history.

Cognitive eating restraint scores are associated with body fatness but not with other measures of dieting in women

Nearly 50% of women report dieting to lose weight, but the ability of cognitive eating restraint (CER) scores to separate women based on indicators of restricted intake has not been adequately demonstrated. We examined the ability of the CER subscale of the eating inventory to distinguish differences in resting energy expenditure (REE), body composition, cortisol, dietary intake, and physical activity, in a group of women. Subjects (20.4+/-2.3 years) were divided into high (score>9; n=31) and low (score< or =9; n=34) CER groups based on questionnaire responses. Indirect calorimetry was used to measure REE and dual-energy X-ray absorptiometry to measure body composition. Salivary and 24-hour urinary cortisol were measured by bioassays. Food frequency questionnaires and 4-day food records, physical activity recalls, and anthropometric measures were completed. Women in the high CER group possessed more fat mass (p<0.05) and higher body fat percent (p<0.05) and consumed more servings of fruits and vegetables per day (p<0.05) compared to women in the low CER group. Differences in other indicators were not observed between CER groups. Our findings suggest that cognitive restraint and body fatness may not be independent of one another.

Prediction equations for resting energy expenditure in overweight and normal-weight black and white children

BACKGROUND

Accurate estimation of children's resting energy expenditure (REE) is important for planning dietary therapy.

OBJECTIVE

Our objective was to compare the utility of 5 REE prediction equations in a diverse sample of young children.

DESIGN

REE was obtained in 502 black and white girls and boys aged 6-11 y by using indirect calorimetry at 4 US sites. Measured REE and REE predicted from the equations were compared.

RESULTS

None of the equations provided both accurate and unbiased estimates of REE. Two new sets of sex-specific equations including race as a factor were generated and evaluated. One set used easily measured variables-females: REE = 0.046 x weight - 4.492 x 1/height(2) - 0.151 x race + 5.841; males: REE = 0.037 x weight - 4.67 x 1/height(2) - 0.159 x race + 6.792-and accounted for 72% and 69%, respectively, of REE variance. The other set used body-composition variables-females: REE = 0.101 x fat-free mass + 0.025 x fat mass + 0.293 x height(3) - 0.185 x race + 1.643; males: REE = 0.078 x fat-free mass + 0.026 x fat mass - 2.646 x 1/height(2) - 0.244 x race + 4.8-and accounted for 75% and 71%, respectively, of REE variance. When split by race and adiposity, the small bias generated could be corrected to within 0.25 MJ (60 kcal) of the mean measured value.

CONCLUSION

Sex-specific equations must take race into account to predict REE adequately in children.

Minnesota leisure time activity questionnaire and doubly labeled water in adolescents

PURPOSES

To validate the energy expenditure estimated from The Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) with total energy expenditure (TEE) measured by doubly labeled water (DLW), and to present and examine the validity of an extended version of the MLTPAQ with additional questions about inactivity during leisure time (eMLTPAQ), in a sample of Swedish 15-yr-old adolescents.

METHODS

Thirty-five 15-yr-old adolescents were interviewed using the eMLTPAQ. In addition to anthropometry, indirect calorimetry was measured to assess basal metabolic rate, and TEE was assessed by the DLW method over a 14-d period.

RESULTS

Energy expenditure calculated from MLTPAQ correlated well with TEEDLW (r=0.49, P<0.01), and the correlation increased when including questions about inactivity (r=0.73, P<0.01). However, eMLTPAQ underestimated TEE in 34 of the 35 students, with a mean difference between the methods of 2.8 MJ.d(-1) (95% limits of agreement: -0.1 to 5.6 MJ.d(-1)), which mainly was explained by a relative high intensity in the time which remained unreported.

CONCLUSION

eMLTPAQ is valid in ranking adolescents energy expenditure and in describing patterns of leisure time physical activities.

Is there an advantage in normalising the results of the Helicobacter pylori [13C]urea breath test for CO2 production rate in children?

The urea breath test (UBT) is a non-invasive diagnostic test to detect the presence of Helicobacter pylori in the stomach, and is the simplest way to confirm eradication after treatment. The test is based on the capacity of H. pylori to secrete the enzyme urease, which hydrolyses urea to ammonia and carbon dioxide. The aim of this study was to determine whether there is an advantage in expressing the results of UBTs in terms of urea hydrolysis rate (UHR), rather than breath 13C enrichment alone. Retrospective analysis of data collected between 1995 and 2002 from 260 patients undergoing UBTs was performed. The cut-offs for positive tests using breath 30-minute enrichment (E30), UHR calculated using VCO2 estimated from height and weight (H/WT) and VCO2 estimated from weight only were determined using two-graph receiver operator characteristic (TG-ROC) analysis. The cut-off points were 3.5/1000 or 38.7 ppm 13C excess, 7.04 micromol/h and 7.08 micromol/h, respectively. There was no advantage in expressing the results as UHR (theta0, Theta-zero, where sensitivity = specificity = 0.97 (UHR H/WT), 0.98 (UHR WT) and 1.00 (E30)) rather than breath 13CO2 enrichment alone. Differences in the extent of H. pylori colonisation and urease activity are more important than variation in VCO2 in determining breath 13CO2 enrichment in the UBT.

Enteral and parenteral nutrition in the care of patients with short-bowel syndrome

Short-bowel syndrome is a challenging entity for the gastroenterologist, requiring integration of medical, nutritional, surgical and psychological therapies. Treatment must be based on the patient's age, remaining gastrointestinal anatomy, baseline nutritional status and underlying general health as well as the numerous complications which may arise. This chapter reviews physiological alterations that occur with short-bowel syndrome and how therapies can be tailored to most adequately meet the needs of these patients. Emphasis on early stages of therapy to enhance intestinal adaptation is focused on as management during this time has a significant impact on the long-term outcome of these patients.

Assessment of energy expenditure in children and adolescents

PURPOSE OF THE REVIEW

This is a review on recent studies regarding methodological aspects of assessment of energy expenditure in children and adolescents.

RECENT FINDINGS

A variety of methods used for assessment of different components of energy expenditure has been validated and used in children and adolescents. Reference values derived from representative groups of healthy children and adolescents are now available. Variations in the different components of energy expenditure and physical activity have been proposed to be associated with weight gain, and the prevalence of overweight and obesity. However, recent cross-sectional and longitudinal data in children and adolescents do not provide strong evidence for this idea. In contrast, hypermetabolism, which is frequently seen in critically ill children, may contribute to their tissue catabolism. In this case beta blockade seems to be a way to increase 'metabolic economy' and thus to reduce tissue catabolism. In chronically ill children and adolescents (e.g. patients with cystic fibrosis and sickle cell anemia) energy expenditure is also frequently increased and group specific algorithms are needed for predicting energy expenditure when measurement facilities are not available.

SUMMARY

Methods for assessment of the different components of energy expenditure have been validated in children and adolescents. The combined use of these methods together with detailed analyses of body composition is recommended for future studies. In patients with acute or chronic illness measurements of energy expenditure are necessary if disease-specific algorithms are not available.

[Influence of energy expenditure on childhood obesity]

OBJECTIVES

To study differences in resting energy expenditure (REE) according to its determining factors (sex, weight, body fat mass, lean body mass) and in the oxidation of energy substrates in obese and non-obese children.

PATIENTS AND METHODS

We studied 71 children (39 obese and 32 non-obese) aged from 4.1 to 13.6 years. The male/female ratio was 34/37. Energy expenditure (EE) was measured by using open circuit indirect calorimetry. The oxidation of energy substrates was calculated from oxygen consumption, carbon dioxide production, and urinary nitrogen excretion from urea. Body composition was determined by anthropometry.

RESULTS

REE (kcal/day), adjusted for anthropometric parameters and body composition, was higher in boys than in girls. The absolute REE was significantly higher in obese than in non-obese children (1512.82 6 234.47 vs 1172.59 6 190.20) and was higher or the same when adjusted for its determinants. Compared with the non-obese group, the obese group presented a significantly higher percentage of fat oxidation (57.15 6 10.68 vs 51.08 6 13.61, p 5 0.04), a lower percentage of carbohydrate oxidation (30.10 6 9.85 vs 36.34 6 13.61, p 5 0.03) and a lower respiratory quotient (0.79 6 0.03 vs 0.82 6 0.04, p 5 0.02). No differences were found between male and female subjects in the percentages of carbohydrate, fat, and protein oxidation.

CONCLUSIONS

We obtained the followings conclusions: a) When adjusted for anthropometric measurements and body composition, REE was significantly higher in boys than in girls; b) REE was higher in obese than in non-obese children, after adjustment for lean body mass; and c) Compared with the control group, obese children presented a higher percentage of fat oxidation, a lower percentage of carbohydrate oxidation, and a lower respiratory quotient.