Body composition and energy expenditure in Duchenne muscular dystrophy

OBJECTIVE: To investigate the relationship between resting energy expenditure (REE) and body composition in Duchenne Muscular Dystrophy (DMD). DESIGN: An observational study. SETTING: University Research Centre. SUBJECTS: Nine Duchenne children (age range 6-12 y), mean relative weight 128%, agreed to undergo the investigation and all of them completed the study; INTERVENTIONS: Assessment of body composition (total body fat and skeletal muscle mass) by magnetic resonance imaging and resting energy expenditure by indirect calorimetry. MAIN OUTCOME MEASURES: Fat mass (FM; kg and percentage weight), fat-free mass (FFM; kg and percentage weight), muscle mass (kg and percentage weight), resting energy expenditure (kJ/kg body weight and kJ/kg fat-free mass). RESULTS:: In Duchenne children fat mass averages 32% and total skeletal muscle mass 20% of body weight. Resting energy expenditure per kg of body weight falls within the normal range for children of the same age range, while when expressed per kg of FFM is significantly higher than reference values. No relationship was found between REE and total skeletal muscle mass. CONCLUSIONS: Our results do not demonstrate a low REE in DMD boys; on the contrary REE per kg of FFM is higher than normal, probably due to the altered FFM composition. We suggest that the development of obesity in DMD children is not primarily due to a low REE but to other causes such as a reduction in physical activity and or overfeeding.     

Little impact of resting energy expenditure on childhood weight and body composition:: A longitudinal study (EarlyBird 47)

The role of resting energy expenditure (REE) in the development of obesity in children is controversial. Our aim was to test the hypothesis that REE has a meaningful impact on change in weight or body composition in healthy children. Resting energy expenditure by indirect calorimetry and body composition by dual-energy x-ray absorptiometry were measured in 236 children (131 boys) on 7 annual occasions (7-13 years). The effect of REE at 7 years on change in weight and body composition was analyzed using linear mixed effects models. In neither sex was there an interaction between REE at 7 years and change in weight (P > .9). There were weak associations between REE at 7 years and change in body composition in boys but not in girls: for a 418 kJ (100 kcal) lower REE at 7 years, an increase in rate of change in fat mass of approximately 0.1 kg/y and in percentage of fat of 0.2% per year and a decrease in fat-free mass of 0.1 kg/y. Change in REE during follow-up was not significantly associated with body composition changes in either sex (P > .06). Thus, REE has little impact on the wide variation in weight gain at this age; although in boys, some fat was simply exchanged for lean, the effect was small. Resting energy expenditure does not appear to provide an explanation for childhood obesity.     

Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery

BACKGROUND: Little is known about the determinants of individual variability in body weight and fat loss after gastric bypass surgery or about the effects of massive weight loss induced by this surgery on energy requirements. OBJECTIVES: The objectives were to determine changes in energy expenditure and body composition with weight loss induced by gastric bypass surgery and to identify presurgery predictors of weight loss. DESIGN: Thirty extremely obese women and men with a mean (+/- SD) age of 39.0 +/- 9.6 y and a body mass index (BMI; in kg/m(2)) of 50.1 +/- 9.3 were tested longitudinally under weight-stable conditions before surgery and after weight loss and stabilization (14 +/- 2 mo). Total energy expenditure (TEE), resting energy expenditure (REE), body composition, and fasting leptin were measured. RESULTS: Subjects lost 53.2 +/- 22.2 kg body weight and had significant decreases in REE (-2.4 +/- 1.0 MJ/d; P < 0.001) and TEE (-3.6 +/- 2.5 MJ/d; P < 0.001). Changes in REE were predicted by changes in fat-free mass and fat mass. The average physical activity level (TEE/REE) was 1.61 at both baseline and follow-up (P = 0.98). Weight loss was predicted by baseline fat mass and BMI but not by any energy expenditure variable or leptin. Measured REE at follow-up was not significantly different from predicted REE. CONCLUSIONS: TEE and REE decreased by 25% on average after massive weight loss induced by gastric bypass surgery. REE changes were predicted by loss of body tissue; thus, there was no significant long-term change in energy efficiency that would independently promote weight regain.     

Energy balance in children and young adults receiving haemodialysis for chronic renal failure

This study was designed to determine the contribution of energy expenditure to the energy imbalance seen in uraemic children. Resting energy expenditure (REE) was measured using open-circuit indirect calorimetry in eight uraemic haemodialysed subjects aged 9.3-20.4 years and in 10 healthy children. Linear correlations between REE and both body weight and fat-free mass as measured by anthropometry were found in both controls and uraemic subjects (respectively: r = 0.76 and r = 0.88 for body weight and r = 0.73 and r = 0.90 for fat-free mass). Measured REE in uraemic patients was not different from the value predicted by using actual body weight and fat-free mass in the regression equation of REE on body weight and fat-free mass in controls (paired t test: p = 0.70 and p = 0.19 respectively). These data suggest that the energy imbalance seen in uraemic children is not due to increased energy expenditure and is therefore probably due to decreased food intake.     

Energy balance in children and young adultsreceiving haernodialysis for chronic renal failure

This study was designed to determine the contribution of energy expenditure tothe energy imbalance seen in uraemic children. Resting energy expenditure (REE) was measured using open-circuit indirect calorimetry in eight uraemic haemodialysed subjects aged 9.3–20.4 years and in 10 healthy children. Linear correlations between REE and both body weight and fat-free mass as measured by anthropometry were found in both controls and uraemic subjects (respectively: r = 0.76 and r = 0.88 for body weight and r = 0.73 and r = 0.90 for fat-free mass). Measured REE in uraemic patients was not different from the value predicted by using actual body weight and fat-free mass in the regression equation of REE on body weight and fat-free mass in controls (paired t test: p = 0.70 and p = 0.19 respectively). These data suggest that the energy imbalance seen in uraemic children is not due to increased energy expenditure and is therefore probably due to decreased food intake.     

Calculating energy requirements for men with HIV/AIDS in the era of highly active antiretroviral therapy

OBJECTIVES: 1. To determine if resting energy expenditure (REE) adjusted for body composition is elevated in HIV-positive males when compared with healthy controls in the era of highly active antiretroviral therapy. 2. To examine the accuracy of prediction equations for estimating REE in people with HIV. 3. To determine if REE adjusting for body composition is significantly different between those HIV-positive subjects reporting lipodystrophy (LD) or weight loss (>or=5%) and those who are weight stable when compared to controls. DESIGN: Cross-sectional study. SETTING: Tertiary referral hospital HIV unit and an outpatient clinic specializing in HIV care. SUBJECTS: HIV-positive males (n=70) and healthy male controls (n=16). METHODS: REE was measured using indirect calorimetry. Body composition was assessed using bioelectrical impedance analysis. RESULTS: 1. REE when adjusted for fat-free mass and fat mass using the general linear model (analysis of covariance) was greater in HIV-positive subjects than controls (7258+/-810 kJ, n=70 vs 6615+/-695 kJ, n=16, P<0.05). 2. The Harris and Benedict, Schofield, Cunningham and the two equations previously published by Melchior and colleagues in HIV-positive subjects all gave an estimate of REE significantly different from the measured REE in the HIV-positive subjects, therefore a new prediction equation was developed. The inability of the published equations to predict REE in the different HIV-positive subgroups reflected the heterogeneity in body composition. 3. REE adjusted for fat-free and fat mass was significantly greater in the both the HIV patients who were weight stable and those with lipodystrophy compared with the healthy controls. CONCLUSION: REE is significantly higher in HIV-positive males when compared with healthy controls. Body composition abnormalities common in HIV render the use of standard prediction equations for estimating REE invalid. When measuring REE in HIV-positive males adjustment steps should include fat-free and fat mass.     

Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women

OBJECTIVE: To compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK) and low-fat (LF) diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE) in overweight/obese men and women. DESIGN: Randomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restricted (-500 kcal/day) diets: a VLCK diet with a goal to decrease carbohydrate levels below 10% of energy and induce ketosis and a LF diet with a goal similar to national recommendations (%carbohydrate:fat:protein = ~60:25:15%). SUBJECTS: 15 healthy, overweight/obese men (mean +/- s.e.m.: age 33.2 +/- 2.9 y, body mass 109.1 +/- 4.6 kg, body mass index 34.1 +/- 1.1 kg/m2) and 13 premenopausal women (age 34.0 +/- 2.4 y, body mass 76.3 +/- 3.6 kg, body mass index 29.6 +/- 1.1 kg/m2). MEASUREMENTS: Weight loss, body composition, trunk fat (by dual-energy X-ray absorptiometry), and resting energy expenditure (REE) were determined at baseline and after each diet intervention. Data were analyzed for between group differences considering the first diet phase only and within group differences considering the response to both diets within each person. RESULTS: Actual nutrient intakes from food records during the VLCK (%carbohydrate:fat:protein = ~9:63:28%) and the LF (~58:22:20%) were significantly different. Dietary energy was restricted, but was slightly higher during the VLCK (1855 kcal/day) compared to the LF (1562 kcal/day) diet for men. Both between and within group comparisons revealed a distinct advantage of a VLCK over a LF diet for weight loss, total fat loss, and trunk fat loss for men (despite significantly greater energy intake). The majority of women also responded more favorably to the VLCK diet, especially in terms of trunk fat loss. The greater reduction in trunk fat was not merely due to the greater total fat loss, because the ratio of trunk fat/total fat was also significantly reduced during the VLCK diet in men and women. Absolute REE (kcal/day) was decreased with both diets as expected, but REE expressed relative to body mass (kcal/kg), was better maintained on the VLCK diet for men only. Individual responses clearly show the majority of men and women experience greater weight and fat loss on a VLCK than a LF diet. CONCLUSION: This study shows a clear benefit of a VLCK over LF diet for short-term body weight and fat loss, especially in men. A preferential loss of fat in the trunk region with a VLCK diet is novel and potentially clinically significant but requires further validation. These data provide additional support for the concept of metabolic advantage with diets representing extremes in macronutrient distribution.     

Optimizing oral nutritional drink supplementation in patients with chronic obstructive pulmonary disease

Nutritional support is indicated in some patients with chronic obstructive pulmonary disease to restore nutritional status and improve functional capacity. However, the efficacy of nutritional supplements is sometimes disappointing, partly owing to a compensatory drop in habitual food intake. We retrospectively studied the effect of nutritional drink supplements, differing in portion size and energy content, on weight gain and body composition. Thirty-nine patients with stable chronic obstructive pulmonary disease, participating in an 8-week pulmonary rehabilitation programme and eligible for nutritional support, were studied. Group A (n 19) received three portions of 125 ml (2380 kJ), whereas group B (n 20) received three portions of 200 ml (3350 kJ) daily. The macronutrient composition of the regimens was similar (20 % protein, 60 % carbohydrates and 20 % fat). Lung function, body weight, body composition (by bio-electrical impedance analysis), habitual dietary intake (by dietary history) and resting energy expenditure (by ventilated hood) were determined. Weight gain was compared with expected weight as predicted by a computer simulation model. Although patients in both groups significantly increased in weight, this increase was higher in group A (A, 3.3 (sd 1.9) kg; B, 2.0 (sd 1.2) kg; P=0.019), while receiving less energy. The observed weight gain in group A was similar to that expected, but in group B it was lower than expected (P<0.001). In both groups, fat-free mass and fat mass were gained in a ratio of 2:1, fat-free mass increasing primarily during the first 4 weeks. This study illustrates that there might be an optimum for the portion size of nutritional drink supplements in chronic obstructive pulmonary disease and that more is not always better.     

The effect of a high protein-low calorie diet on the energy expenditure of obese adolescents.

Resting energy expenditure (REE), and body composition, as fat-free mass (FFM) and fat mass, were determined in seven obese adolescents before and after weight loss of a mean 13.5 kg on an approximately 800 kcal/d (3349 kJ), high protein reducing diet regimen. Ideal body weight decreased from 166% to 142% in 8 weeks. There were no significant changes in total body potassium (TBK), extracellular water (ECW), intracellular water (ICW) or total body water (TBW) with weight loss. The REE (kcal/d) fell from 2034 +/- 392 (8514 +/- 1641 kJ) to 1762 +/- 453 (7376 +/- 1896 kJ) with weight loss (P < 0.05). However, when the REE was expressed as kcal/body weight there was no difference between before and after weight loss, 21.4 +/- 2.8 (90 +/- 21 kJ) and 21.6 +/- 4.5 (90 +/- 19 kJ). Similarly, when REE was examined in relation to FFM (kcal/kg) before and after weight loss, there were also no significant differences: 34.6 +/- 5.1 (145 +/- 21 kJ) and 32.1 +/- 7.9 (134 +/- 33 kJ).     

Use of [14C]-sodium bicarbonate/urea to measure total energy expenditure in overweight men and women before and after low calorie diet induced weight loss

The aim of this study was to evaluate the use of the [14C]-sodium bicarbonate/urea technique to measure the change in total energy expenditure after weight loss and a period of weight maintenance. Eleven healthy subjects (6 men and 5 women aged 50 +/- 3 yrs, BMI 34.1 +/-2.1 kg/ m2, body fat 38.7 +/-3%) underwent 8 weeks of energy restriction using a combination of "Modifast" formula and one small meal per day (approximately 3.3 MJ/day). For an additional 2 weeks, subjects resumed a solid food diet that contained enough energy to stabilize body weight at the newly reduced level. Body composition, total energy expenditure (TEE), resting energy expenditure (REE) and the thermic effect of a 2.7 MJ test meal (TEF) were measured at both weeks 0 and 10. At week 10 as compared to week 0, body weight decreased by 12.2+/-1.6 kg (12.5%)(P<0.001). Total fat and lean mass decreased by 8.4+/-1.0 kg (20.4%) and 3.8+/-0.7 kg (6.7%), respectively (P< 0.001). REE decreased by 500+/-128 kJ/day (5.6+/-1.3%)(P<0.002). Decreases in the TEE (0.18 +/-;3.7%)and TEF(1.4+/-0.9%) were not significant. In conclusion, although [14C]-sodium bicarbonate/urea was well tolerated and did not interfere with normal daily activities, it did not have sufficient sensitivity to accurately measure weight loss induced changes in TEE in the range of 0.1-10%.     

Resting Energy Expenditure and Related Factors in 6- to 9-Year-Old Southern African Children of Diverse Population Groups

Lower resting energy expenditure (REE) may partially explain the disproportionate prevalence of overweight/obesity among black African women. As no previous studies have investigated the REE of Southern African (South. Afr.) children, we aimed to determine, by sex and population group, the REE of 6- to 9-year-old urban school children. In a cross-sectional study with quota sampling, REE was measured with indirect calorimetry (IC). Confounders considered were: body composition (BC) (fat-free mass (FFM), FFM index, fat mass (FM), FM index), assessed using multifrequency bioelectrical impedance analysis, and physical activity (PA) measured with a pedometer. Multivariate regression was used to calculate REE adjusted for phenotypes (BC, z-scores of weight-for-age, height-for-age, body mass index-for-age) and PA. Sex and population differences in REE were determined with two-way ANOVA. Ninety-four healthy children (59.6% girls; 52.1% black) with similar socioeconomic status and PA opportunities participated. Despite BC variations, sex differences in REE were not significant (41 kcal/day; P = 0.375). The REE of black participants was lower than of white (146 kcal/day; P = 0.002). When adjusted for FFM and HFA z-score, the differences in REE declined but remained clinically meaningful at 91 kcal/day (P = 0.039) and 82 kcal/day (P = 0.108), respectively. We recommend the development of population-specific REE prediction equations for South. Afr. children.     

Energy requirements in frail elderly people: a review of the literature

This review collates studies of healthy, sick, underweight (BMI < or = 21 kg/m2) and very elderly people (> or = 90 yr), in whom resting energy expenditure (REE) was measured using indirect calorimetry. We have observed the following: (1) REE, when adjusted for differences in both body weight and fat-free mass (FFM), is similar in healthy and in sick elderly people being 20 and 28 kcal/kg of FFM per day, respectively, (2) their nutritional status influences their energy requirements given that weight-adjusted REE increases in line with a decrease in BMI, (3) total energy expenditure is lower in sick elderly people given that their physical activity level, i.e. the ratio of total energy expenditure to REE, is reduced during disease averaging at 1.36, (4) energy intake (EI) being only 1.23 x REE is insufficient to cover energy requirements in sick elderly patients, whereas the EI of healthy elderly people appears sufficient to cover requirements, and finally, (5) gender ceases to be a determinant of REE in people aged 60 yr or over, with the Harris & Benedict equation capable of accurately predicting mean REE in this population, whether healthy or sick.     

An underfeeding study in healthy men and women provides further evidence of impaired regulation of energy expenditure in old age

The effect of aging on energy regulation remains controversial. We compared the effects of underfeeding on changes in energy expenditure and respiratory quotient in young normal weight men and women [YNW, age 25.7 +/- 3.2 y(SD), body mass index (BMI) 23.1 +/- 1.6 kg/m(2)], young overweight men and women (YOW, age 26.1 +/- 3.5 y, BMI 27.7 +/- 2.1 kg/m(2)) and older (OLD) men and women (age 68.4 +/- 3.3 y, BMI 27.4 +/- 3.4 kg/m(2)). The thermic effect of feeding (TEF) during weight maintenance, and changes in resting energy expenditure (REE) and respiratory quotient were determined in response to undereating by an average 3.75 MJ/d for 6 wk. In addition, body composition was measured. No significant differences among the groups were observed in TEF, fasting and postprandial respiratory quotient, or the change in fasting respiratory quotient with underfeeding. However, REE adjusted for fat-free mass and fat mass was significantly lower in OLD subjects compared with YNW and YOW subjects (P < 0.05). In addition, the REE response to weight change was significantly attenuated in the OLD subjects (P = 0.023). These data suggest that the responsiveness of energy expenditure to negative energy balance is attenuated in old age, and provide further support for the hypothesis that mechanisms of energy regulation are broadly disregulated in old age.     

Repeated measurements of energy intake, energy expenditure and energy balance in lactating Bangladeshi mothers

OBJECTIVE: To examine changes in energetic parameters and nutritional status of chronically malnourished lactating women over a period of 13 months postpartum. DESIGN: A study of 15 lactating Bangladeshi mothers, of whom eight were tea pluckers and seven housewives, was conducted over a 13 months period from the birth of the child. Anthropometric measurements and body composition were determined on five occasions (at 3.5, 5.5, 7.5, 10 and 13 months) and energy expenditure (heart rate monitoring method), and energy intake (3-day weighing) on three occasions at 3.5, 10 and 13 months. RESULTS: The mothers, all of whom were of low BMI (range 14.9-18.1 kg/m2 at the end of the study) undertook high levels of physical activity (pluckers more so than housewives). There was evidence of weight loss over the 13 months, particularly between the fourth and sixth months postpartum, mainly due to a significant decrease in fat-free mass. Food intake and expenditure were higher in pluckers than housewives but energy balance was not significantly different, although workers were, on average, in negative balance on all three occasions. Food intake was based on cereals and fat deficient. CONCLUSIONS: A Bangladeshi sample of breast-feeding mothers studied over 13 months postpartum showed evidence of chronic malnutrition with women living on very low fat diets. All mothers, either housewives or tea pluckers were involved in energy demanding activities. There was a general tendency towards negative energy balance. Mothers lost weight, mainly fat-free mass over the study period.     

World Health Organization equations have shortcomings for predicting resting energy expenditure in persons from a modern, affluent population: generation of a new reference standard from a retrospective analysis of a German database of resting energy expenditure

BACKGROUND: Reference standards for resting energy expenditure (REE) are widely used. Current standards are based on measurements made in the first part of the past century in various races and locations. OBJECTIVE: The aim of the present study was to investigate the application of the World Health Organization (WHO) equations from 1985 in healthy subjects living in a modern, affluent society in Germany and to generate a new formula for predicting REE. DESIGN: The study was a cross-sectional and retrospective analysis of data on REE and body composition obtained from 2528 subjects aged 5-91 y in 7 different centers between 1985 and 2002. RESULTS: Mean REE varied between 5.63 and 8.07 MJ/d in males and between 5.35 and 6.46 MJ/d in females. WHO prediction equations systematically overestimated REE at low REE values but underestimated REE at high REE values. There were significant and independent effects of sex, age, body mass or fat-free mass, and fat mass on REE. Multivariate regression analysis explained up to 75% of the variance in REE. Two prediction formulas including weight, sex, and age or fat-free mass, fat mass, sex, and age, respectively, were generated in a subpopulation and cross-validated in another subpopulation. Significant deviations were still observed for underweight and normal-weight subjects. REE prediction formulas for specific body mass index groups reduced the deviations. The normative data for REE from the Institute of Medicine underestimated our data by 0.3 MJ/d. CONCLUSIONS: REE prediction by WHO formulas systematically over- and underestimates REE. REE prediction from a weight group-specific formula is recommended in underweight subjects.     

Resting energy expenditure can be assessed by fat-free mass in female athletes regardless of body size

Energy requirements can be estimated from resting energy expenditure (REE). However, little is known about factors influencing REE in Japanese female athletes. This study was performed to evaluate the relationship between REE and body composition in Japanese female athletes with a wide range of body sizes. Ninety-three athletes (age 20.3±1.2 y, height 162.8±6.4 cm, body weight (BW) 57.0±9.2 kg, fat-free mass (FFM) 45.4±6.2 kg) were classified into three groups according to BW: small-size (S) (n=34), medium-size (M) (n=34), and large-size (L) (n=25). Systemic and regional body compositions (skeletal muscle (SM), fat mass (FM), bone mass (BM), and residual mass (RM)) were estimated by dual energy X-ray absorptiometry (DXA). Measured resting energy expenditure (REEm) was evaluated by indirect calorimetry. Marked differences were found in REEm (S: 1,111±150, M: 1,242±133, L: 1,478±138 kcal/d), and systemic and regional body compositions among the three groups. REEm was strongly correlated with FFM, and absolute values of RM and SM increased significantly according to body size. There was good agreement between REEm and estimated REE (REEe) from the specific metabolic rates of four major organ tissue level compartments. These data indicate that REE for female athletes can be attributed to changes in organ tissue mass, and not changes in organ tissue metabolic rate. That is, change in REE can be explained mainly by the change in FFM, and REE can be assessed by FFM in female athletes regardless of body size.     

血糖稳定的2型糖尿病患者的静息能量消耗

目的观察血糖控制良好的2型糖尿病患者静息能量消耗（REE）的特点。方法采用代谢车测量45例血糖稳定的2型糖尿病患者的REE，记录其一般情况、生化指标、Harris-Benedict和Owen公式计算基础能量消耗预测值，并进行比较分析。结果血糖稳定的2型糖尿病患者的静息能量消耗实测值与Harris-Benedict及Owen公式预测值比较差异无统计学意义（P〉0．05），相关分析显示REE与性别、年龄、体重、身高、体表面积、去脂组织显著相关（P〈0．05），与体重指数、脂肪组织、空腹血糖、餐后2h血糖、糖化血红蛋白、总胆固醇、三酰甘油、总蛋白、白蛋白、血红蛋白无相关性（P〉0．05），多元逐步回归分析显示去脂组织和年龄与REE关系最密切。结论血糖良好的2型糖尿病患者的REE并不增高，决定其REE的因素与健康个体相似，测定REE能更好地指导糖尿病的医学营养治疗。     

Relation between energy expenditure and body composition in man: specific energy expenditure in vivo of fat and fat-free tissue

The relationship between energy expenditure and body composition, in terms of fat and fat-free masses, has previously been described by a variety of predictive regression equations with parameters devoid of physiological content. We present here results obtained by calculating the specific energy expenditure, ie, the energy expenditure per unit of mass, of fat and fat-free tissue on the basis of measurements of the total energy expenditure (EE), the masses of fat (FM), and fat-free (FFM) tissue using the following simple model: EE = k1.FM + k2.FFM where k1 and k2 are the specific energy expenditures of fat and fat-free tissue, respectively. The results of observations on 104 women at rest yielded values for k1 and k2 of 0.31 and 1.35 watts/kg of fat and fat-free mass, respectively, with standard errors of estimate of 0.074 and 0.052 watts/kg, respectively. Analysis of several series of measurements, from other sources and on smaller samples of subjects, yielded similar values at rest but with larger standard errors of estimate. Data from subjects performing varying amounts of work in 24-h measurements showed, as expected, larger values for both tissues. The results explain to a very large extent the well-established relation between resting metabolic rate and body weight, ie, a linear relation with a non-zero intercept. The results also offer a clear-cut explanation for the well known difference in energy expenditure between men and women with the same body weight.     

Body composition as a determinant of energy expenditure: a synthetic review and a proposed general prediction equation

Differences in body composition have often been examined in conjunction with measurements of energy expenditure in men and women. Numerous studies during the past decade examined the relationship between resting energy expenditure (REE) and the components of a two-compartment model of composition, namely the fat-free mass (FFM) and the fat mass (FM). A synthetic review of these studies confirms a primary correlation between REE and FFM in adults over a broad range of body weights. A generalized prediction equation is proposed as REE = 370 +/- 21.6 x FFM. This equation explains 65-90% of the variation in REE. Several studies suggest, further, that FFM predicts total daily energy expenditure (TDEE) equally well. An independent contribution by FM to the prediction of either REE or TDEE is not supported for the general population, perhaps reflecting the relative constancy of the absolute FM in nonobese individuals. In the subset of obese women, FM may be a significant predictor.     

Weight loss and resting energy expenditure in patients with chronic hepatitis C before and during standard treatment

ObjectiveInfection with hepatitis C virus (HCV) is a serious public health problem worldwide. In clinical studies, weight loss has been reported in 11% to 29% of patients treated with pegylated interferon-α-2a/2b. Few reports have tried to explain such a weight loss. The aim of this study was to evaluate nutritional status, body composition, and resting energy expenditure (REE) in patients with chronic hepatitis C before and during treatment with pegylated interferon and ribavirin.MethodsThis was a prospective study with the evaluation of patients with hepatitis C virus before and after 12 wk of treatment with pegylated interferon and ribavirin. The evaluation consisted of anthropometry (weight, height, body mass index, and waist circumference), and body composition was determined by bioelectrical impedance analysis. The REE of each individual was obtained by indirect calorimetry. To compare the two phases of treatment, the Wilcoxon test was used. The significance level was 5%.ResultsSubjects had significant weight loss during treatment with a consequent decrease in body mass index. This weight decrease was accompanied by a significant decrease in body fat and no decrease in fat-free mass. There was a significant decrease in energy intake as assessed by 24-h recall. However, there was no change in REE and in REE corrected for fat-free mass.ConclusionOur study of patients with hepatitis C treatment showed that these patients had significant weight loss and this was not associated with changes in energy expenditure. However, we observed a significant decrease in energy intake, pointing to a possible need for intervention measures to decrease the damage.