Characteristics of body composition and resting energy expenditure in lean young women

The number of lean young women has been increasing. Fear of being fat may induce unnecessary attempts to reduce body weight, which can cause several types of illness. Many investigations have demonstrated dysfunction of the hypothalamus and metabolic differences in patients with anorexia nervosa. However, it is unclear whether there are any differences in physical characteristics between women with lower body weight and no illness compared to those of normal body weight. In this study, we investigated the differences in body composition, biochemical parameters, and resting energy expenditure (REE) between young women with low and normal body mass index (BMI). Twenty lean women (BMI<18.5 kg/m(2)) and 20 normal women (18.5≤BMI<25 kg/m(2)) were recruited for this study. Body composition, biochemical parameters, and REE (REEm: measurement of REE) were measured, and the REE (REEe: estimation of REE) was estimated by using a prediction model. Marked differences were found in body composition. All of the values of blood analysis were in the normal ranges in both groups. REEm (kcal/d and kcal/kg BW/d) was significantly lower in lean than in normal women, but there were no significant differences in the REEm to fat free mass (FFM) ratio between the two groups. In addition, there was good agreement between REEm and REEe obtained from the specific metabolic rates of four tissue organs. These data indicate that the lean women without any illness have normal values of biochemical parameters and energy metabolism compared to women with normal BMI.     

Effects of Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis.

BACKGROUND: To determine the extent and effects of increased metabolic demand represented by Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis (CF). METHODS: The study comprised 18 stable children with CF, of whom 10 (6 male/4 female) were colonized with Pseudomonas species and 8 (4 male/4 female) were not. The groups were of similar age range and genotype. Measured resting energy expenditure (REE) was performed by open circuit indirect calorimetry and compared with predicted REE calculated from standard equations. Body composition was determined by dual-energy x-ray absorptiometry, including lean body mass (LBM), fat mass (FM), bone mineral density (BMD), and anterior-posterior spine density (APS); these were compared using z-scores. Routine pulmonary function testing assessed forced vital capacity, forced expiratory volume in 1 second (FEV1), and forced expiratory flow over middle half of vital capacity (FEF25% to 75%); these were compared as percent predicted. RESULTS: As expected, results of pulmonary function testing showed significant deterioration among the children colonized with Pseudomonas species when compared with the children who were not, while standard anthropometry showed no differences in weight, height, or weight-for-height percentile and respective z-scores. Although a trend of lower LBM was noted among the children colonized with Pseudomonas species, no significant differences were found between these children and children who were not colonized with Pseudomonas species when z-scores for LBM, FM, BMD, or APS were compared during body composition analysis. In addition, neither REE as kilocalories per day (kcal/d) nor REE expressed as a percent predicted by standard equations discriminated between subgroups of children colonized with Pseudomonas species and children who were not. However, metabolic demand, expressed as resting energy expenditure in kilocalories per kilogram (kcal/kg) of LBM (REE/LBM), revealed significant differences between children colonized with Pseudomonas species and children who were not (75.4+/-4.4 vs 58.6+/-2.9 kcal/kg, p < .05). CONCLUSIONS: The effect of Pseudomonas colonization on metabolic demand in children with CF can be accurately assessed by expressing resting energy expenditure as kilocalorie per kilogram of LBM, the active metabolic component of the body. The 50% increase in REE/LBM seen in the children colonized with Pseudomonas species represents the metabolic demand from the inflammatory burden and work of breathing resulting from the effects of the Pseudomonas colonization. The trend of a lower LBM in the children colonized with Pseudomonas species makes this finding even more dramatic.     

New equation for the prediction of resting energy expenditure during pregnancy

ObjectiveThe equation for the prediction of resting energy expenditure (REE) during pregnancy is unknown. The aim of this prospective longitudinal study was to determine a new equation for prediction of REE in pregnancy.MethodsA total of 152 randomly recruited healthy pregnant Czech women (nonsmokers, not users of chronic medications or abusers of alcohol or drugs, normoglycemic, euthyroid, and not anemic) were divided into two cohorts: group 1 (n = 31) was used for determination of the equation for calculation of pregnant REE and group 2 (n = 121) for cross-validation of this formula. The REE of the pregnant women in both study groups was examined by indirect calorimetry (REE-IC) along with anthropometry after 12 h of fasting in four periods of pregnancy. A statistical comparison of three basic equations (Harris Benedict, Schofield, and Kleiber) was used for the prediction of REE.ResultsThrough correlation analysis and linear regression, a new predictive equation of REE during pregnancy (P REE) was derived from the Harris Benedict equation. We observed high concordance between values from P REE and REE-IC in group 2. Analysis of alternative predictive equations of REE with the addition of kilocalories and a corrected multiplication factor for each stage of pregnancy expressed low concordance.ConclusionsThe equation for REE in kilocalories during pregnancy, P REE = 346.43943 + 13.962564 × W + 2.700416 × H ? 6.826376 × A (W, weight; H, height; A, age), with SD 116 kcal/d, corresponds closely to REE-IC and maternal changes in each phase of pregnancy. P REE can be applied for prediction of REE during gestation.     

Regional lean body mass and resting energy expenditure in non-obese adults

Summary Objective To study the effect of regional lean body mass (LBM) on resting energy expenditure (REE). Design Cross-sectional study in a homogenous group of 26 young healthy non-obese subjects. Methods Regional body composition was assessed by dual-energy X-ray absorptiometry (DEXA). REE was measured by indirect calorimetry. Results REE showed positive relationships with whole body LBM (LBM_b; r=0.89) as well as with regional LBM (LBM_trunk = LBM_t, r = 0.88, and LBM_arms+legs = LBM_e for LBM_extremities, r = 0.89) with non-zero intercepts (between 1.86 and 2.83 MJ/d). REE per kg LBM_b falls as LBM_b increases (r = 0.77). By contrast, REE adjusted for regional distribution of LBM (i. e. the ratio of LBM_t to LBM_e) increases as LBM_b increases (r = 0.91) showing a near-zero intercept (i. e. 0.048 MJ/d). Adjusting REE for LBM_b as well as for the ratio of LBM_t to LBM_e can be used for comparison between subjects. Conclusions Our data suggest that regional distribution of LBM is a determinant of REE. Assessment of LBM_t and LBM_e by DEXA provides a possibility to adjust for the non-linearity of REE on LBM_b. Received: 11 April 2001, Accepted: 12 June 2001     

Influence of resting energy expenditure on weight gain in adolescents taking second-generation antipsychotics

Background & aims

: Weight gain is an undesirable side effect of second-generation antipsychotics (SGAs). We performed this study to examine the influence of SGAs on resting energy expenditure (REE) and the relationship of REE to weight gain in adolescent patients.

Methods

Antipsychotic-naïve or quasi-naïve (<72 h of exposure to antipsychotics) adolescent patients taking olanzapine, quetiapine, or risperidone in monotherapy were followed up for one year. We performed a prospective study (baseline, 1, 3, 6, and 12 months after treatment) based on anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry (Deltatrac™ II MBM-200) to measure REE. We also analyzed metabolic and hormonal data and adiponectin concentrations.

Results

Forty-six out of the 54 patients that started treatment attended at least 2 visits, and 16 completed 1 year of follow-up. Patients gained 10.8 ± 6.2 kg (60% in the form of fat mass) and increased their waist circumference by 11.1 ± 5.0 cm after 1 year of treatment. The REE/kg body mass ratio decreased (p = 0.027), and the REE/percentage fat-free mass (FFM) ratio increased (p = 0.007) following the fall in the percentage of FFM during treatment. Weight increase was significantly correlated with the REE/percentage FFM ratio at all the visits (1–3–6–12 months) (r = 0.69, p = 0.004 at 12 months).

Conclusions

SGAs seem to induce a hypometabolic state (reflected as decreased REE/kg body mass and increased REE/percentage FFM). This could explain, at least in part, the changes in weight and body composition observed in these patients.     

A longitudinal study of resting energy expenditure relative to body composition during puberty in African American and white children

BACKGROUND: Body composition and resting energy expenditure (REE) have not been examined longitudinally during puberty. OBJECTIVE: The purpose of this longitudinal study was to examine the influence of pubertal maturation on REE relative to body composition in African American and white children. DESIGN: The study included 92 white and 64 African American children (mean age at baseline: 8.3 and 7.9 y, respectively) from Birmingham, AL. The children had 2-5 annual measurements of fat mass (FM), lean mass (LM), and REE. The Tanner stages of the children ranged from 1 to 5. Mixed-model repeated-measures analyses were used to test the change in REE relative to body composition with increasing Tanner stage among ethnic and sex groups. RESULTS: LM increased from Tanner stage 1 to subsequent stages. FM relative to LM decreased from Tanner stage 1 to stages 3, 4, and 5 but not from stage 1 to stage 2. The African American children had relatively higher limb LM and lower trunk LM than did the white children. REE declined with Tanner stage after adjustment for ethnicity, sex, FM, and LM. This decline was significant from Tanner stage 1 to stages 3, 4, and 5 but not to Tanner stage 2. After adjustment for age, Tanner stage, FM, and LM or LM distribution, REE was significantly higher in white than in African American children (by approximately 250 kJ/d). CONCLUSION: In a large sample of children at various Tanner stages, we found an ethnic difference in REE after adjustment for age, Tanner stage, FM, and LM that was not explained by the difference in LM distribution.     

Resting energy expenditure and body composition following cerebro-vascular accident

The aim of this study was to measure resting energy expenditure (REE) in patients routinely admitted to hospital following a cerebro-vascular accident (CVA). The REE of 15 patients (8 female; 7 male) was measured using indirect calorimetry 24-72 hours after the CVA; 11 patients (7 female; 4 male) were measured again 10-14 days later. Body composition was assessed using skin-fold thickness, near infra-red interactance and bioelectrical impedance techniques. Initial REE in females was 1133 kcal/day (+/-67) and in males 1526 kcal/day (+/-111). There was little or no difference in REE or body composition between the first and second measurements. REE was between 95%-107% of the values predicted by 10 reference tables and equations and up to 118% of that predicted by another. We conclude that the total energy requirements of patients following a stroke are not high, probably because of decreased physical activity and changes in muscular tone subsequent to CVA.     

Comparison of energy prediction equations with measured resting energy expenditure in children with sickle cell anemia

OBJECTIVE: To determine the accuracy of energy prediction equations when compared with measured resting energy expenditure (REE) in children with sickle cell anemia. To develop a modified equation that more accurately estimates the energy needs of children with sickle cell anemia and to cross-validate these on a different set of patients (test patients). DESIGN: REE was measured in children using indirect calorimetry and compared with predicted values using the Harris-Benedict and the Food and Agriculture Organization/World Health Organization/United Nations University equations (WHO). SUBJECTS/SETTING: Eighteen patients participated in the original sample that compared predicted with measured energy expenditure. The modified equations were developed using the original 18 patients. A test population of 20 different patients was used to validate the modified equations. STATISTICAL ANALYSIS: Wilcoxon signed-rank test was performed to compare measured with predicted REE. The correlation analysis method and multiple linear regression method were used to develop 2 modified versions for the Harris-Benedict and WHO prediction equations. RESULTS: When compared with the mean predicted REE using the Harris-Benedict and WHO equations, the mean measured REE was 14% and 12% greater than both (P=.005 and P=.014, respectively). Two modified equations were developed from the Harris-Benedict and WHO equations. Based on the data from the test patients, the mean measured REE was 15% greater than the mean predicted REE based on the Harris-Benedict and WHO equations (P=.0001 for both). When the modified Harris-Benedict and WHO equations were used, there was almost no difference in the mean measured REE and the mean predicted REE (mean difference using Harris-Benedict = 14, P = .9273; mean difference using WHO = -13, P = .6215). CONCLUSION: Both energy prediction equations underestimated REE in children with sickle cell anemia. The 2 modified versions of the energy prediction equations that we propose predicted the energy needs of these children much more accurately; however, the modified equations need to be validated through application to other children with sickle cell anemia.     

Lean-body-mass composition and resting energy expenditure before and after long-term overfeeding.

This report deals with the association between the constituents of lean body mass (LBM) and resting metabolic rate (RMR) before and after a 100-d overfeeding period. Computed-tomography (CT) scan of 22 young adult males at nine different body levels were used to estimate adipose tissue mass (ATMCT), LBMCT, skeletal-muscle mass (SMMCT), and non-muscular LBMCT (NM-LBMCT). Before overfeeding, all body constituents, except ATMCT, were significantly correlated with RMR. Only body mass changes were significantly correlated with RMR changes. Comparison of these results with those of several studies in the literature reveals that the relationship between RMR and fat-free mass is highly influenced by the size of the SD for the latter variable. In stepwise-multiple-regression analysis, only SMMCT could be used to predict RMR. It was concluded that SMMCT and ATMCT, but not NM-LBMCT, increased during overfeeding and that the best correlates of RMR remain LBMCT, SMMCT, and body mass.     

Accuracy of predictive methods to estimate resting energy expenditure of thermally-injured patients

BACKGROUND: The purpose of this study was to evaluate the bias and precision of 46 methods published from 1953 to 2000 for estimating resting energy expenditure (REE) of thermally injured patients. METHODS: Twenty-four adult patients with > or =20% body surface area burn admitted to a burn center who required specialized nutrition support and who had their REE measured via indirect calorimetry (IC) were evaluated. Patients with morbid obesity, human immunovirus, malignancy, pregnancy, hepatic or renal failure, neuromuscular paralysis, or those requiring a FiO2 >50% or positive end expiratory pressure (PEEP) > or =10 cm H2O were excluded. One steady-state measured REE measurement (MEE) was obtained per patient. The methods of Sheiner and Beal were used to assess bias and precision of these methods. The formulas were considered unbiased if the 95% confidence interval (CI) for the error (kilocalories per day) intersected 0 and were considered precise if the 95% CI for the absolute error (%) was within 15% of MEE. RESULTS: MEE was 2780+/-567 kcal/d or 158%+/-34% of the Harris Benedict equations. None of the methods was precise (< or =15% CI error). Over one-half (57%) of the 46 methods had a 95% confidence interval error >30% of the MEE. Forty-eight percent of the methods were unbiased, 33% were biased toward overpredicting MEE, and 19% consistently underpredicted MEE. The pre-1980s methods more frequently overpredicted MEE compared with the 1990 to 2000 (p < .01) and 1980 to 1989 (p < .05) published methods, respectively. The most precise unbiased methods for estimating MEE were those of Milner (1994) at a mean error of 16% (CI of 10% to 22%), Zawacki (1970) with a mean error of 16% (CI of 9% to 23%), and Xie (1993) at a mean error of 18% (CI of 12% to 24%). The "conventional 1.5 times the Harris Benedict equations" was also unbiased and had a mean error of 19% (CI of 9% to 29%). CONCLUSIONS: Thermally injured patients are variably hypermetabolic and energy expenditure cannot be precisely predicted. If IC is not available, the most precise, unbiased methods were those of Milner (1994), Zawacki (1970), and Xie (1993).     

Betaine supplementation decreases plasma homocysteine concentrations but does not affect body weight,body composition,or resting energy expenditure in human subjects

BACKGROUND: Betaine (trimethylglycine) is found in several tissues in humans. It is involved in homocysteine metabolism as an alternative methyl donor and is used in the treatment of homocystinuria in humans. In pigs, betaine decreases the amount of adipose tissue. OBJECTIVE: The aim of the study was to examine the effect of betaine supplementation on body weight, body composition, plasma homocysteine concentrations, blood pressure, and serum total and lipoprotein lipids. DESIGN: Forty-two obese, white subjects (14 men, 28 women) treated with a hypoenergetic diet were randomly assigned to a betaine-supplemented group (6 g/d) or a control group given placebo for 12 wk. The intervention period was preceded by a 4-wk run-in period with a euenergetic diet. RESULTS: Body weight, resting energy expenditure, and fat mass decreased significantly in both groups with no significant difference between the groups. Plasma homocysteine concentrations decreased in the betaine group ( +/- SD: 8.76 +/- 1.63 micro mol/L at 4 wk, 7.93 +/- 1.52 micro mol/L at 16 wk; P = 0.030 for the interaction of time and treatment). Diastolic blood pressure decreased without a significant difference between the groups. Serum total and LDL-cholesterol concentrations were higher in the betaine group than in the control group (P < 0.05). CONCLUSION: A hypoenergetic diet with betaine supplementation (6 g daily for 12 wk) decreased the plasma homocysteine concentration but did not affect body composition more than a hypoenergetic diet without betaine supplementation did.     

学龄儿童运动能量消耗与人体成分的关系

目的　探讨学龄期儿童运动能量消耗（AEE）与人体成分之间的关系。方法　以上海市杨浦区二联小学三、四年级62名学生为研究对象,使用代谢车测定运动能量消耗,利用生物电阻抗法测定人体成分,包括体质量、体质量指数、体脂率、脂肪含量、去脂体质量、脂肪含量指数、去脂体质量指数、肥胖度和AEE,比较超重肥胖组与非超重肥胖组儿童各指标的差异,并探讨其关系。结果　男生超重肥胖组和非超重肥胖组的运动时间［（9.70±1.91）min 比（10.00±1.97）min;t=0.336,P=0.739］、总AEE［（198.74±53.33）kJ 比 （171.54±41.75）kJ;t=-1.422,P=0.165］、AEE相对值［（0.46±0.09）kJ/(min·kg）比（0.51±0.04）kJ/(min·kg); t=2.043,P=0.051］差异均无统计学意义,超重肥胖组AEE绝对值高于非超重肥胖男生组［（20.06±3.14）kJ/min比（16.93±1.85）kJ/min;t=-2.910,P=0.007］。女生超重肥胖组与非超重肥胖组相比运动时间更短［（7.35±3.05）min 比 （9.98±1.82）min;t=2.509,P=0.027］、AEE相对值更小［（0.41±0.09）kJ/(min·kg）比 （0.51±0.07）kJ/(min·kg）;t=3.244,P=0.003］,但两组总AEE［（129.29±71.13）kJ 比 （161.50±35.38）kJ;t=1.351,P=0.203］、AEE绝对值［（16.82±3.26）kJ/min 比 （16.17±2.00）kJ/min; t=-0.676,P=0.504］差异均无统计学意义。控制年龄和性别因素后,男生AEE绝对值与体质量指数（P=0.015）、肥胖度(P=0.010)、脂肪含量(P=0.047)、去脂体质量(P=0.010）和去脂体质量指数(P=0.003)呈显著正相关,女生AEE绝对值与体成分各指标无相关性。AEE相对值与体质量指数（男：P=0.000,女：P=0.000）、肥胖度（男：P=0.002,女：P=0.000）、体脂率（男：P=0.000,女：P=0.001）、脂肪含量（男：P=0.000,女：P=0.000）、去脂体质量（男：P=0.002,女：P=0.022）和脂肪含量指数（男：P=0.000,女：P=0.000）呈显著负相关。结论　肥胖儿童AEE与体成分有关,肥胖程度越高,AEE相对值越少。儿童的体型、体成分与能量代谢存在着复杂的联系。     

Estimation of resting energy expenditure by anthropometry

The role of anthropometry in estimating resting energy expenditure (REE) has been assessed in 142 clinically stable patients. Ninety eight patients had cancer (54 weight stable, 44 weight losing) and 44 patients had nonmalignant illness (27 weight stable, 17 weight losing). Mid-arm muscle circumference (MAMC) measurements correlated significantly with REE measured by indirect calorimetry in each of the groups studied. Weight loss significantly affected this correlation whereas cancer did not. The correlation in weight stable patients was poorer than that in weight losing patients, possibly reflecting inaccuracy of anthropometric measurements due to subcutaneous adipose tissue. Significant correlations were also observed between mid-arm circumference (MAC) and REE, and between MAMC and whole body oxygen consumption.REE can be estimated from MAMC measurements in weight stable and weight losing patients with benign or malignant disease. This simple method may be of value in estimating REE where indirect calorimetry facilities are unavailable.