Changes in resting energy expenditure and body composition in anorexia nervosa patients during refeeding

Energy expenditure during nutritional rehabilitation: a scoping review to investigate hypermetabolism in individuals with anorexia nervosa

BACKGROUND

Weight gain and nutritional rehabilitation are essential first steps to achieve medical stabilization in anorexia nervosa, and frequent resistance to weight gain requires patients to consume high kilocalorie loads. Adaptive hypometabolism is common when patients begin treatment, and rebound hypermetabolism is suspected to be a significant barrier to weight gain. The aim of this review was to summarize existing data describing metabolic changes in anorexia nervosa during weight restoration. The reported findings challenge current hypotheses of weight gain resistance and highlight key areas for future research.

METHODS

Using scoping review guidelines, three databases were searched for studies investigating metabolic changes in anorexia nervosa before and after renourishment. Two reviewers systematically screened the titles and abstracts of 447 articles, and full-text versions of 106 studies were assessed for eligibility. A total of 36 studies were included for review. Data regarding the study description, sample population (including age, weight, BMI, duration of treatment, and caloric intake), and metabolic variable descriptions were extracted.

RESULTS

Female patients with anorexia nervosa from studies across 13 countries were included. Across the studies, average BMI increased from 13.7 kg/m2 at admission to 17.57 kg/m2. Patients presented to treatment with clinically reduced energy expenditure levels. After varying levels of nutritional rehabilitation and weight restoration, measured energy expenditure increased significantly in 76% of the studies. Energy expenditure values at the second timepoint increased to the standard range for normal weight female teenagers and adults. Despite these increases, the studies do not indicate the presence of a hypermetabolic state during renourishment. Additionally, all studies including both measured and predicted energy expenditure reported that predicted energy expenditure overestimated measured values.

CONCLUSION

This study provides a detailed evaluation of the literature investigating energy expenditure and metabolic rate in patients with anorexia nervosa before and following a period of renourishment. The findings from this review identify important gaps in the current beliefs of energy expenditure in anorexia nervosa and highlight a need for further exploration of metabolic alterations during weight restoration.

Microbiota in anorexia nervosa: potential for treatment

Anorexia nervosa (AN) is characterised by the restriction of energy intake in relation to energy needs and a significantly lowered body weight than normally expected, coupled with an intense fear of gaining weight. Treatment of AN is currently based on psychological and refeeding approaches, but their efficacy remains limited since 40% of patients after 10 years of medical care still present symptoms of AN. The intestine hosts a large community of microorganisms, called the "microbiota", which live in symbiosis with the human host. The gut microbiota of a healthy human is dominated by bacteria from two phyla: Firmicutes and, majorly, Bacteroidetes. However, the proportion in their representation differs on an individual basis and depends on many external factors including medical treatment, geographical location and hereditary, immunological and lifestyle factors. Drastic changes in dietary intake may profoundly impact the composition of the gut microbiota, and the resulting dysbiosis may play a part in the onset and/or maintenance of comorbidities associated with AN, such as gastrointestinal disorders, anxiety and depression, as well as appetite dysregulation. Furthermore, studies have reported the presence of atypical intestinal microbial composition in patients with AN compared with healthy normal-weight controls. This review addresses the current knowledge about the role of the gut microbiota in the pathogenesis and treatment of AN. The review also focuses on the bidirectional interaction between the gastrointestinal tract and the central nervous system (microbiota-gut-brain axis), considering the potential use of the gut microbiota manipulation in the prevention and treatment of AN.

Clinical Correlates of Measured and Predicted Resting Energy Expenditure in Patients with Anorexia Nervosa: A Retrospective Cohort Study

Resting energy expenditure (REE; i.e., the calorie amount required for 24 h during a non-active period) is an important parameter in nutritional rehabilitation of patients with anorexia nervosa (AN). This study determined whether age, body mass index, AN duration/subtype/specific symptoms/clinical severity, cognitive function alterations, and psychiatric comorbidities influenced REE or the difference between the calculated and estimated REE. Patients with AN who were followed at a daycare treatment facility between May 2017 and January 2020 (n = 138) underwent a complete assessment that included the MINI, Eating Disorder Examination Questionnaire, d2 test of attention, body fat composition by bioelectrical impedance analysis (BIA) and REE measurement by indirect calorimetry (REEIC). AN subtype (N = 66 for restrictive subtype and N = 69 for non-restrictive subtype; p = 0.005), free-fat mass (<0.001), and fat mass (<0.001) were associated with REEIC. Age (p < 0.001), height (p = 0.003), and AN duration (N = 46 for <3 years and N = 82 for ≥3 years; p = 0.012) were associated with the difference between estimated REE (using the Schebendach equation) and measured REEIC. Therefore, the Schebendach equation was adjusted differently in the two patients’ subgroups (AN duration ≤ or >3 years). Overall, REE was higher in patients with restrictive than non-restrictive AN. In the absence of BIA measures, REE-estimating equations should take into account AN duration.

Resting energy expenditure in acutely ill and stabilized patients with anorexia nervosa and bulimia nervosa

OBJECTIVE

Determining resting energy expenditure (REE) may be important in the nutritional assessment of adolescents with eating disorders (EDs). Calculated equations assessing REE, developed according to data from healthy people, may under- or overestimate REE in EDs. We have sought to compare the REE measured in clinical settings to that calculated using equations in actively ill adolescents with anorexia nervosa (AN) and bulimia nervosa (BN), and following stabilization of weight and disordered eating.

METHODS

Thirty-five female adolescents with AN and 25 with BN were assessed at admission to inpatient treatment and at discharge. REE was measured using indirect calorimetry (DELTATRAC Metabolic Monitor). Expected REE was calculated using the Harris-Benedict equation.

RESULTS

An overestimation of expected versus measured REE was found for both patients with AN and BN, both at admission and discharge. Second, the differences between expected and measured REE were significantly less robust in BN versus AN. Third, REE before renourishing was lower in inpatients with AN versus BN. Fourth, the REE of patients with AN (both measured and expected) increased from admission to discharge, to a greater extent than expected solely from the increase in weight. The difference between admission and discharge expected and measured REE was significant also in patients with BN.

DISCUSSION

Our findings suggest that predicted and measured REE are different in both AN and BN, and that both expected and measured REE are not useful in the planning of renourishing programs in patients with AN.

Medical Complications of Eating Disorders in Youth

Eating disorders affect a significant number of individuals across the life span and are found among all demographic groups (including all genders, socioeconomic statuses, and ethnicities). They can cause malnutrition, which can have significant effects on every organ system in the body. Cardiovascular complications are particularly dangerous and cause eating disorders to have the highest mortality rate of all mental illnesses. This article outlines the medical assessment and treatment of malnutrition due to disordered eating.

Gut-Brain Interactions: Implications for a Role of the Gut Microbiota in the Treatment and Prognosis of Anorexia Nervosa and Comparison to Type I Diabetes

Anorexia nervosa has poor prognosis and treatment outcomes and is influenced by genetic, metabolic, and psychological factors. Gut microbes interact with gut physiology to influence metabolism and neurobiology, although potential therapeutic benefits remain unknown. Type 1 diabetes is linked to anorexia nervosa through energy dysregulation, which in both disease states is related to the gut microbiota, disordered eating, and genetics.

Metabolic Barriers to Weight Gain in Patients With Anorexia Nervosa: A Young Adult Case Report

Background: Over-proportionally high energy requirements in some patients with anorexia nervosa (AN) have been reported, but their exact origin remains unclear. Objective: To objectively measure metabolic alterations in an AN patient with high energy requirements as judged by clinical observation. Materials and Methods: We present the case of a young woman with AN (index patient, IP; 19 years, admission BMI 13.9 kg/m²). After 3 months of treatment at BMI 17.4 kg/m², we assessed her resting energy expenditure (REE), respiratory exchange ratio (RER), diet-induced thermogenesis (DIT), seated non-exercise physical activity (NEPA in Volt by infrared sensors), and exercise activity thermogenesis (EAT) in a metabolic chamber; body composition (bioimpedance analysis), energy intake (15d-food protocol), physical activity (accelerometry) and endocrine parameters. The IP was compared for REE, RER, DIT and seated NEPA to six AN patients (AN-C) and four healthy women (HC-1), and for EAT to another six healthy women (HC-2). Results: Our IP showed high REE (110% of predicted REE according to Harris & Benedict) and high seated NEPA (47% increase over AN-C, 40% over HC-1), whereas DIT (IP: 78 vs. HC-1: 145 ± 51 kJ/180 min) and EAT (IP: 157 vs. HC-2: 235 ± 30 kJ/30 min) were low, when compared with HC. The other AN patients showed a lower REE (AN: 87 ± 2% vs. HC: 97 ± 2% predicted) at increased DIT (AN: 187 ± 91 vs. HC: 145 ± 51 kJ/180 min) when compared with HC. RER of the IP was low (IP: 0.72 vs. 0.77 in AN-C; 0.77 in HC-1 and 0.80 in HC-2). Conclusions: Complex and variable disturbances of energy metabolism might exist in a subgroup of patients with AN during refeeding, which could lead to unexpectedly high energy requirements. Future studies need to confirm the existence, and investigate the characteristics and prevalence of this subgroup. Clinical trial Registry number: NCT02087280, https://www.clinicaltrials.gov/.

The use of metabolic balance studies in the objective discrimination between intestinal insufficiency and intestinal failure

Background: In research settings that use metabolic balance studies (MBSs) of stable adult patients with short bowel syndrome, intestinal failure (IF) and dependence on parenteral support (PS) have been defined objectively as energy absorption <84% of calculated basal metabolic rate (BMR), wet weight (WW) absorption <23 g · kg body weight^-1 · d^-1, or both. Objective: This study aimed to explore and validate these borderlines in the clinical setting.Design: Intestinal absorption was measured from April 2003 to March 2015 in 175 consecutive patients with intestinal insufficiency (INS) in 96-h MBSs. They had not received PS 3 mo before referral.Results: To avoid the need for PS, the minimum absorptive requirements were energy absorption of ≥81% of BMR and WW absorption of ≥21 g · kg body weight^-1 · d^-1, which were equivalent to findings in research settings (differences of 3.6% and 8.7%; P = 0.65 and 0.60, respectively). Oral failure defined as energy intake <130% of calculated BMR or WW intake <40 g · kg body weight^-1 · d^-1 was seen in 71% and 82% of the 10% of patients with the lowest energy absorption and WW absorption, respectively.Conclusions: In clinical settings, the borderlines between INS and IF were not significantly different from those in research settings, even in an unselected patient population in which oral failure was also a predominant cause of nutritional dyshomeostasis. MBSs may be recommended to identify the individual patient in the spectrum from INS to IF, to objectivize the cause of nutritional dyshomeostasis (oral failure, malabsorption, or both), and to quantify the effects of treatment.

A systematic review of approaches to refeeding in patients with anorexia nervosa

OBJECTIVE

Given the importance of weight restoration for recovery in patients with anorexia nervosa (AN), we examined approaches to refeeding in adolescents and adults across treatment settings.

METHODS

Systematic review of PubMed, PsycINFO, Scopus, and Clinical Trials databases (1960-2015) using terms refeeding, weight restoration, hypophosphatemia, anorexia nervosa, anorexia, and anorexic.

RESULTS

Of 948 screened abstracts, 27 met these inclusion criteria: participants had AN; reproducible refeeding approach; weight gain, hypophosphatemia or cognitive/behavioral outcomes. Twenty-six studies (96%) were observational/prospective or retrospective and performed in hospital. Twelve studies published since 2010 examined approaches starting with higher calories than currently recommended (≥1400 kcal/d). The evidence supports 8 conclusions: 1) In mildly and moderately malnourished patients, lower calorie refeeding is too conservative; 2) Both meal-based approaches or combined nasogastric+meals can administer higher calories; 3) Higher calorie refeeding has not been associated with increased risk for the refeeding syndrome under close medical monitoring with electrolyte correction; 4) In severely malnourished inpatients, there is insufficient evidence to change the current standard of care; 5) Parenteral nutrition is not recommended; 6) Nutrient compositions within recommended ranges are appropriate; 7) More research is needed in non-hospital settings; 8) The long-term impact of different approaches is unknown;

DISCUSSION

Findings support higher calorie approaches to refeeding in mildly and moderately malnourished patients under close medical monitoring, however the safety, long-term outcomes, and feasibility outside of hospital have not been established. Further research is also needed on refeeding approaches in severely malnourished patients, methods of delivery, nutrient compositions and treatment settings.

Changes in Body Composition in Anorexia Nervosa: Predictors of Recovery and Treatment Outcome

The restoration of body composition (BC) parameters is considered to be one of the most important goals in the treatment of patients with anorexia nervosa (AN). However, little is known about differences between AN diagnostic subtypes [restricting (AN-R) and binge/purging (AN-BP)] and weekly changes in BC during refeeding treatment. Therefore, the main objectives of our study were twofold: 1) to assess the changes in BC throughout nutritional treatment in an AN sample and 2) to analyze predictors of BC changes during treatment, as well as predictors of treatment outcome. The whole sample comprised 261 participants [118 adult females with AN (70 AN-R vs. 48 AN-BP), and 143 healthy controls]. BC was measured weekly during 15 weeks of day-hospital treatment using bioelectrical impedance analysis (BIA). Assessment measures also included the Eating Disorders Inventory-2, as well as a number of other clinical indices. Overall, the results showed that AN-R and AN-BP patients statistically differed in all BC measures at admission. However, no significant time×group interaction was found for almost all BC parameters. Significant time×group interactions were only found for basal metabolic rate (p = .041) and body mass index (BMI) (p = .035). Multiple regression models showed that the best predictors of pre-post changes in BC parameters (namely fat-free mass, muscular mass, total body water and BMI) were the baseline values of BC parameters. Stepwise predictive logistic regressions showed that only BMI and age were significantly associated with outcome, but not with the percentage of body fat. In conclusion, these data suggest that although AN patients tended to restore all BC parameters during nutritional treatment, only AN-BP patients obtained the same fat mass values as healthy controls. Put succinctly, the best predictors of changes in BC were baseline BC values, which did not, however, seem to influence treatment outcome.

Anorexia nervosa and body fat distribution: a systematic review

The aim of this paper was to conduct a systematic review of body fat distribution before and after partial and complete weight restoration in individuals with anorexia nervosa. Literature searches, study selection, method development and quality appraisal were performed independently by two authors, and data was synthesized using a narrative approach. Twenty studies met the inclusion criteria and were consequently analyzed. The review had five main findings. First, during anorexia nervosa adolescent females lose more central body fat, while adult females more peripheral fat. Second, partial weight restoration leads to greater fat mass deposition in the trunk region than other body regions in adolescent females. Third, after short-term weight restoration, whether partial or complete, adults show a central adiposity phenotype with respect to healthy age-matched controls. Fourth, central fat distribution is associated with increased insulin resistance, but does not adversely affect eating disorder psychopathology or cause psychological distress in female adults. Fifth, the abnormal central fat distribution seems to normalize after long-term maintenance of complete weight restoration, indicating that preferential central distribution of body fat is a transitory phenomenon. However, a discrepancy in the findings has been noted, especially between adolescents and adults; besides age and gender, these appear to be related to differences in the methodology and time of body composition assessments. The PROSPERO Registry—Anorexia Nervosa and Body Fat Distribution: A Systematic Review (CRD42014008738).

Body composition, eating disorder psychopathology, and psychological distress in anorexia nervosa: a longitudinal study

BACKGROUND

Although the effect of immediate weight restoration on body composition and body fat distribution has previously been studied in anorexia nervosa (AN), its influence in women with AN on eating disorder psychopathology and psychological distress has not previously been investigated to our knowledge.

OBJECTIVES

We assessed body composition and fat mass distribution before and after body weight restoration and investigated any relation between changes in body fat patterns of patients with AN treated in a specialist inpatient unit and their eating disorder and psychological distress features.

DESIGN

Body composition was measured by using dual-energy X-ray absorptiometry in 50 female, adult patients with AN before and after complete weight restoration [body mass index (BMI; in kg/m²) ≥18.5] and 100 healthy control subjects matched by age and posttreatment BMI of study group participants. Eating disorder psychopathology and psychological distress were assessed in the AN group before and after weight restoration by using the Eating Disorder Examination interview and the Global Severity Index of the Brief Symptom Inventory (BSI-GSI), respectively.

RESULTS

After the achievement of complete weight restoration, patients with AN had higher trunk (P < 0.001), android (P < 0.001), and gynoid (P < 0.001) fat masses and lower arm (P < 0.001) and leg (P = 0.001) fat masses with respect to control subjects. No relation was shown between body-composition variables and eating disorder psychopathology in the AN group, and the only significant predictor of change in BSI-GSI was the baseline BSI-GSI score.

CONCLUSION

The normalization of body weight in patients with AN is associated with a preferential distribution of body fat in central regions, which does not, however, seem to influence either eating disorder psychopathology or psychological distress scores.

A review of feeding methods used in the treatment of anorexia nervosa

BACKGROUND

Clear evidence based guidelines on the best and safest method of achieving and maintaining normal body weight during inpatient treatment of Anorexia Nervosa (AN) are currently not available. Oral feeding with food alone, high-energy liquid supplements, nasogastric feeding and parenteral nutrition all have the potential to achieve weight gain in the treatment of AN but the advantages and disadvantages of each method have not been comprehensively evaluated. A literature search was undertaken to identify papers describing feeding methods used during inpatient treatment of AN. The selection criteria searched for papers that described the feeding method; and reported weight change variables such as admission and discharge weight in kilograms, or Body Mass Index; or weight change over the course of inpatient treatment.

RESULTS

Twenty-six papers were identified, describing a total of 37 samples with a mean sample size of 58.9 participants, and a range from 6 to 318. The majority (84.6%) of papers were observational cohorts and retrospective chart reviews. The most common feeding method described was nasogastric feeding and food, then high-energy liquid supplements and food.

CONCLUSIONS

There is limited evidence on the efficacy of feeding methods used in the refeeding and nutritional rehabilitation of AN, therefore no conclusion can be made about the most effective method of achieving weight gain during inpatient treatment. While there are a number of papers exploring this issue there is no consistency in the way the information is reported to enable comparisons between the different methods. There is an urgent need for research in this area to guide decision-making in the inpatient management, refeeding and nutritional rehabilitation of AN.

Refeeding hypophosphatemia in adolescents with anorexia nervosa: a systematic review

The rate of adolescents presenting with anorexia nervosa (AN) is increasing. Medically unstable adolescents are admitted to the hospital for nutrition restoration. A lack of global consensus on appropriate refeeding practices of malnourished patients has resulted in inconsistent refeeding practices. Refeeding hypophosphatemia (RH) is the most common complication associated with refeeding the malnourished patient. This review sought to identify the range of refeeding rates adopted globally and the implication that total energy intake and malnutrition may have on RH while refeeding adolescents with anorexia nervosa. Studies were identified by a systematic electronic search of medical databases from 1980 to September 2012. Seventeen publications were identified, including 6 chart reviews, 1 observational study, and 10 case reports, with a total of 1039 subjects. The average refeeding energy intake was 1186 kcal/d, ranging from 125-1900 kcal/d, with a mean percentage median body mass index (% mBMI) of 78%. The average incidence rate of RH was 14%. A significant correlation between malnutrition (% mBMI) and post-refeeding phosphate was identified (R (2) = 0.6, P = .01). This review highlights the disparity in refeeding rates adopted internationally in treating malnourished adolescents with anorexia nervosa. Based on this review, the severity of malnutrition seems to be a marker for the development of RH more so than total energy intake.

Resting energy expenditure assessment in anorexia nervosa: comparison of indirect calorimetry, a multisensor monitor and the Müller equation

The aim of this study was to compare the estimations provided by three different means of measuring the resting energy expenditure (REE) in anorexia nervosa (AN) patients. REE was measured, after 24 h of refeeding, using a portable multisensor body monitor [SenseWear Pro2 Armband (SWA)], FitMate™ method and the Müller equation for individuals with body mass index < 18.5, the latter being based on dual-energy X-ray absorptiometry assessment of body composition. The mean differences between REE values estimated by SWA and those provided by the Müller equation and the FitMate™ method were significantly different from zero in both cases. In contrast, the mean differences between FitMate™ method and Müller equation were weakly significantly different from zero, and a significant correlation was noted between these two methods. In conclusion, the SWA does not appear to be an alternative to FitMate™ and Müller equation methods for assessing REE in AN patients.

A prospective examination of weight gain in hospitalized adolescents with anorexia nervosa on a recommended refeeding protocol

PURPOSE

Current refeeding recommendations for adolescents hospitalized with anorexia nervosa (AN) are conservative, starting with low calories and advancing slowly to avoid refeeding syndrome. The purpose of this study was to examine weight change and clinical outcomes in hospitalized adolescents with AN on a recommended refeeding protocol.

METHODS

Adolescents aged 13.1-20.5 years were followed during hospitalization for AN. Weight, vital signs, electrolytes, and 24-hour fluid balance were measured daily. Percent median body mass index (%MBMI) was calculated as 50th percentile BMI for age and gender. Calories were prescribed on admission and were increased every other day.

RESULTS

Thirty-five subjects with a mean (SD) age of 16.2 (1.9) years participated over 16.7 (6.4) days. Calories increased from 1,205 (289) to 2,668 (387). No subjects had refeeding syndrome; 20% had low serum phosphorus. Percent MBMI increased from 80.1 (11.5) to 84.5 (9.6); overall gain was 2.10 (1.98) kg. However, 83% of subjects initially lost weight. Mean %MBMI did not increase significantly until day 8. Higher calories prescribed at baseline were significantly associated with faster weight gain (p = .003) and shorter hospital stay (p = .030) in multivariate regression models adjusted for %MBMI and lowest heart rate on admission.

CONCLUSIONS

Hospitalized adolescents with AN demonstrated initial weight loss and slow weight gain on a recommended refeeding protocol. Higher calorie diets instituted at admission predicted faster weight gain and shorter hospital stay. These findings support the development of more aggressive feeding strategies in adolescents hospitalized with AN. Further research is needed to identify caloric and supplementation regimens to maximize weight gain safely while avoiding refeeding syndrome.

Resting Energy Expenditure in Anorexia Nervosa: Measured versus Estimated

Introduction. Aim of this study was to compare the resting energy expenditure (REE) measured by the Douglas bag method with the REE estimated with the FitMate method, the Harris-Benedict equation, and the Müller et al. equation for individuals with BMI < 18.5 kg/m(2) in a severe group of underweight patients with anorexia nervosa (AN). Methods. 15 subjects with AN participated in the study. The Douglas bag method and the FitMate method were used to measure REE and the dual energy X-ray absorptiometry to assess body composition after one day of refeeding. Results. FitMate method and the Müller et al. equation gave an accurate REE estimation, while the Harris-Benedict equation overestimated the REE when compared with the Douglas bag method. Conclusion. The data support the use of the FitMate method and the Müller et al. equation, but not the Harris-Benedict equation, to estimate REE in AN patients after short-term refeeding.

Obesity and thyroid function

A moderate elevation of thyrotropin (TSH) concentrations, which is associated with triiodothyronine (T3) values in or slightly above the upper normal range, is frequently found in obese humans. These alterations seem rather a consequence than a cause of obesity since weight loss leads to a normalization of elevated thyroid hormone levels. Elevated thyroid hormone concentrations increase the resting energy expenditure (REE). The underlying pathways are not fully understood. As a consequence of the increased REE, the availability of accumulated energy for conversion into fat is diminished. In conclusion, the alterations of thyroid hormones in obesity suggest an adaptation process. Since rapid weight loss is associated with a decrease of TSH and T3, the resulting decrease in REE may contribute towards the difficulties maintaining weight loss. Leptin seems to be a promising link between obesity and alterations of thyroid hormones since leptin concentrations influence TSH release.

Pediatric body composition analysis with dual-energy X-ray absorptiometry

Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children.

Energy metabolism and body composition in long-term recovery from anorexia nervosa

OBJECTIVE

The aim of this study was to determine if energy metabolism and body composition differ between women recovered from anorexia nervosa for 2 or more years (RAN) and control (C) women.

METHOD

Using a cross-sectional design, 16 RAN and 18 C women were studied. Respiratory quotient (RQ) and resting energy expenditure (REE) were measured using indirect calorimetry and body composition using dual energy X-ray absorptiometry.

RESULTS

The REE between RAN and C women was not significantly different, even when adjusted for body composition. However, RAN women had a higher rate of fat oxidation (p = .015), controlling for diet and body composition. There were no significant differences between the groups for body composition, percent body fat, or percent truncal fat mass.

DISCUSSION

Although RAN women have a higher rate of fat oxidation, there were no significant differences in REE or body composition when compared with C women.

Feeding size 0: the challenges of anorexia nervosa. Managing anorexia from a dietitian's perspective

Anorexia nervosa has the highest mortality rate of any psychiatric condition and its management is complex and multi-faceted, requiring a multidisciplinary team approach. Dietitians are an important part of the multidisciplinary team, offering objective nutritional advice with the aim of helping the patient to develop an improved relationship with food. Refeeding patients with a low body weight requires careful management; nonetheless, refeeding the low-weight patient with anorexia presents many additional complications, largely of a psychological nature. Treatment plans need to consider psychological, physical, behavioural and psycho-social factors relating to anorexia nervosa. Currently, there is no consistent approach and a paucity of evidence to support best practice for weight restoration in this group of patients. Tube feeding is utilised at varying BMI in anorexia nervosa, mainly in an inpatient setting. However, its use should be seen as a last resort and limited to a life-saving intervention. Weight restoration is best managed by an experienced dietitian within a specialist eating disorders team, using normal foods. This approach is ideal for nutrition rehabilitation, promoting skills for eating and normal behaviour and providing a longer-term solution by challenging unhelpful coping strategies from the onset. Dietitians have a unique mix of skills and knowledge in numerous areas including nutrition, physiology, psychology, sociology and behaviour change, which can be applied to support patients with thoughts and behaviours around food, weight and appetite. Further research is required into the effectiveness of dietetic interventions in eating disorders in order to establish an evidence base for best practice.

Pediatric body composition analysis with dual-energy X-ray absorptiometry

Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children.

Hypercaloric diets differing in fat composition have similar effects on serum leptin and weight gain in female subjects with anorexia nervosa

Weight regain in subjects with anorexia nervosa is associated with an increase in serum leptin concentrations that is hypothesized to impair full weight restoration. As diets rich in n-3 polyunsaturated fatty acids (PUFA) have been described to lower serum leptin concentrations, we tested the hypothesis that consumption of a hypercaloric diet rich in n-3 PUFA is associated with an attenuated increase in serum leptin and a higher efficiency of body weight gain in subjects with anorexia nervosa. Twenty-five female subjects with anorexia nervosa were enrolled into this controlled dietary intervention study. Four subjects discontinued therapy or participation in the study prematurely, and six were excluded. 15 subjects completed the study. Subjects consumed hypercaloric diets rich in either saturated fatty acids (SFA, n = 8) or n-3 PUFA (n = 7) for 5 weeks. Primary endpoints were the change in serum leptin concentrations and body weight gain relative to energy consumed. Serum leptin concentrations increased distinctly throughout the study (P < .001), and to a similar extend in both groups [+2.9 (SD 2.4) vs. +2.8 (SD 3.4) ng/mL in the SFA- and n-3 PUFA group, respectively; P = .487]. The efficiency of body weight gain also did not differ significantly between groups, with a body weight gain of 63.1 (SD 12.4) vs. 79.2 (SD 26.0) g per 4.2 MJ (1000 kcal) consumed in the SFA- and n-3 PUFA group, respectively (P = .132). Hypercaloric diets rich in either SFA or n-3 PUFA do not differ in their effects on serum leptin concentrations and the efficiency of body weight gain in female subjects with anorexia nervosa.

Measurement of daily activity in restrictive type anorexia nervosa

OBJECTIVE

The assessment of daily activity in patients with restrictive type anorexia nervosa is limited by an absence of accurate and precise technology. We wanted to test a daily activity detecting device named, the physical activity monitoring system (PAMS).

METHOD

Women participants with restrictive type anorexia nervosa (n = 8, 36 +/- 11 years, 17 +/- 2 kg/m(2)) and healthy women participants (n = 8, 30 +/- 11 years, 27 +/- 7 kg/m(2)) were asked to lie, sit, and stand motionless, and walk at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mph while wearing PAMS.

RESULTS

For all restrictive type anorexia nervosa and healthy participants, body posture was correctly detected for all measurements (300/300). There was excellent correlation of an individual's body acceleration with walking velocity and walking energy expenditure (r(2) > .99).

CONCLUSION

The PAMS technology could serve as a tool for lending insight into the pathophysiology of restrictive type anorexia nervosa; and potentially measuring compliance with activity recommendations for medical professionals treating individuals with restrictive type anorexia nervosa.

Energy expenditure in anorexia nervosa: can fat-free mass as measured by bioelectrical impedance predict energy expenditure in hospitalized patients?

Anorexia nervosa (AN) is associated with a reduced metabolically active fat-free mass (FFM) and basal metabolic rate (BMR). Excessive refeeding results in major fat deposition which is not well tolerated by patients. Prediction of BMR is, therefore, a clinical issue during refeeding, but measurement by indirect calorimetry is time-consuming and not widely available. The study aim was to determine if and when BMR could be estimated from prediction formulas based on FFM derived from bioelectrical impedance analysis (BIA) in AN patients during refeeding. Indirect calorimetry and BIA were prospectively measured bi-weekly in 9 AN patients (body mass index 13.7 +/- 0.5 kg/m2) for 10 weeks of refeeding. Initial BMR was 969 +/- 46.7 kcal/d and 27.7 +/- 1.4 kcal/kg FFM, and at week 10 increased to 1360 +/- 44.6 kcal/d and 35.8 +/- 0.8 kcal/kg FFM. While correlations improved with increasing weight, FFM and body mass index, prediction formulas are insufficient to permit prediction of BMR based on weight or FFM, even after 10 weeks of refeeding. To allow for optimal nutritional support, indirect calorimetry measurements may be useful in the early weeks of refeeding because of a large variability of basal metabolic rate between patients.

Metabolic and psychological changes during refeeding in anorexia nervosa

OBJECTIVE

This study aimed to examine resting metabolic rate (RMR) and psychological changes during refeeding in 10 women with anorexia nervosa participating in a partial hospitalization eating disorder program.

RESULTS

Participants' admission RMRs, as assessed by the MedGem Analyzer, were below their RMRs predicted by the Harris- Benedict equation, t(1,9)=5.77, p<0.01. Correlational analyses revealed a trend toward smaller increases in RMR being associated with higher admission BMI (r=-0.49, p=0.08), but not with highest lifetime BMI. Over the course of treatment, RMR per pound of Fat-Free Mass (FFM) increased from the beginning to the middle, t(1,9)=-3.02, p<0.05, and to the end stage of treatment, t(1,9)=-2.53, p<0.05. Scores on the Eating Attitudes Test-26, Eating Disorder Inventory-2, Brief Symptom Inventory (BSI), BSI Depression subscale, and Mizes Anorectic Cognitions scale significantly improved throughout treatment (all p<0.05); however, body dissatisfaction did not improve.

DISCUSSION

Results suggest that weight restoration programs for anorexia nervosa cannot rely on FFM or standard formulas to predict caloric needs throughout refeeding, and that admission BMI is one factor to be considered in predicting caloric needs during refeeding. Furthermore, ways to improve body dissatisfaction during refeeding needs to be more of a treatment focus.

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.

Nutrient intake in community-dwelling adolescent girls with anorexia nervosa and in healthy adolescents

BACKGROUND

Adolescence is a common time for the onset of anorexia nervosa (AN), a condition associated with long-term medical and hormonal consequences.

OBJECTIVE

The objective was to compare the nutrient intakes of community-dwelling girls with AN with those of healthy adolescents and to describe the associations between specific nutrient intakes and nutritionally dependent hormones.

DESIGN

Nutrient intakes in 39 community-dwelling girls with AN and 39 healthy adolescents aged 12.1-18.7 y were determined by using 4-d food records. Fasting adiponectin, leptin, ghrelin, insulin, and insulin-like growth factor I (IGF-I) concentrations were measured. Indirect calorimetry was used to assess respiratory quotient and resting energy expenditure.

RESULTS

In contrast with the control group, the AN group consumed fewer calories from fats (P < 0.0001) and more from carbohydrates (P = 0.0009) and proteins (P < 0.0001). Intake of individual fat components was lower and of dietary fiber higher in the AN group. No significant between-group differences were observed in dietary intakes of calcium, zinc, and iron; however, total intake was greater in the AN group because of greater supplement use (P = 0.006, 0.02, and 0.01, respectively). The AN group had greater intakes of vitamins A, D, and K and of most of the B vitamins, and significantly more girls with AN met the Dietary Reference Intake for calcium (P = 0.01) and vitamin D (P = 0.02) from supplement use. Fat intake predicted ghrelin, insulin, and IGF-I concentrations; carbohydrate intake predicted adiponectin. Resting energy expenditure was lower (P < 0.0001) and leisure activity levels higher in the AN group.

CONCLUSIONS

Despite outpatient follow-up, community-dwelling girls with AN continue to have lower fat and higher fiber intakes than do healthy adolescents, which results in lower calorie intakes. Nutritionally related hormones are associated with specific nutrient intakes.

Dynamic monitoring of restricted eating disorders by indirect calorimetry: a useful cognitive approach

OBJECTIVE

Outpatient treatment in restricted eating disorder: indirect calorimetry during dynamic monitoring.

DESIGN

A retrospective observational study.

SUBJECTS

Twenty seven women affected by restricted eating disorder (essentially anorexia nervosa) with a body mass index [weight (kg)/height (m2)] of 17.29+/-2.47 were studied. The sample was compared as itself control during rehabilitative way.

INTERVENTIONS

Fat mass (FM) and fat free mass (FFM) were determined by anthropometry technique. REE/day and respiratory quotient (RQ,VCO2/VO2) were measured by indirect calorimetry using a Calorimeter Vmax 29n-Sensor Medics-California. Skinfold thickness and circumferences were also measured. Arm muscle area (AMA) and fat area were calculated by formulas reported in Frisancho.

RESULTS

The data indicated a positive correlation between AMA, VO2/ml/min and resting energy expenditure (REE)/day values examined during follow-up of patients. The increase of these parameters indicated a good monitoring index correlated to a FFM recovery during psychonutritional rehabilitation.

CONCLUSION

Indirect calorimetry represents a useful approach for determining REE and prescribing diets in these patients. Moreover, the combined use of anthropometric techniques allows to accurately assess and adjust therapy according to the patient's progress. This study shows that restricted eating disorders are characterized by a recovery of FFM related to improvement of body weight and REE/day. On the contrary, the increase of AFA revealed a recovery of fat-metabolism (corresponding to RQ decrease) and lipid/carbohydrates oxidation improvement, only in the presence, at the same time, of O2 consumption increase.

Body fat redistribution after weight gain in women with anorexia nervosa

BACKGROUND

Body image distortions are a core feature of anorexia nervosa (AN). Increasing evidence suggests that the fat distribution immediately after weight restoration in patients with AN differs from the distribution typical of healthy adult women.

OBJECTIVE

The purpose of this study was to assess body fat distribution before and shortly after normalization of weight in women with AN.

DESIGN

Body composition and fat distribution were assessed by anthropometry, dual-energy X-ray absorptiometry, and whole-body magnetic resonance imaging in 29 women with AN before and after weight normalization and at a single time point in 15 female control subjects. Hormone concentrations were also evaluated in patients and control subjects.

RESULTS

During approximately 10.1 +/- 2.9 wk (range: 4-17.3 wk) of treatment, patients with AN gained 12.2 +/- 3.6 kg, and refed weight (54.1 +/- 4.2 kg) did not differ significantly from that of control subjects (54.7 +/- 4.4 kg). Waist-to-hip circumference ratio (P < 0.006), total trunk fat (P < 0.003), visceral adipose tissue (P < 0.006), and intramuscular adipose tissue (P < 0.003) were significantly greater in the weight-recovered patients than in the control subjects. In contrast, after refeeding, total subcutaneous adipose tissue and skeletal muscle mass did not differ significantly between the patients and control subjects. In patients with AN, serum cortisol decreased and serum estradiol increased significantly with refeeding but not to control concentrations.

CONCLUSIONS

In women with AN, normalization of weight in the short term is associated with an abnormal distribution of body fat. The implications of these findings for the long-term psychological and physical health of women with AN are unknown.

L-tri-iodothyronine is a major determinant of resting energy expenditure in underweight patients with anorexia nervosa and during weight gain

OBJECTIVE

We aimed to define the effect of L-3,5,3'-tri-iodothyronine (T(3)) on metabolic adaptation in underweight patients with anorexia nervosa (AN) as well as during weight gain.

METHODS

This involved clinical investigation of 28 underweight patients with AN, who were compared with 49 normal-weight controls. A subgroup of 17 patients was followed during weight gain. Resting energy expenditure was measured by indirect calorimetry. Body composition was measured by anthropometry as well as bioelectrical impedance analysis. Energy intake (EI) was assessed by a 3-day dietary record. Plasma concentrations of thyroid hormones (thyroxine (T(4)), T(3) and thyrotropin (TSH)) were analyzed by enzyme immunoassays.

RESULTS

When compared with normal-weight women, underweight patients with AN had reduced fat mass (FM) (-71.3%), fat-free mass (FFM) (-13.1%), resting energy expenditure (REE) (-21.8%), T(3)- (-33.4%) and T(4)-concentrations (-19.8%) at unchanged TSH. REE remained reduced after adjustment for FFM (-24.6%). T(3) showed a close association with REE. This association remained after adjustment of REE for FFM. Treatment of underweight AN patients resulted in a mean weight gain of 8.3 kg. This was mainly explained by an increase in FM with small or no changes in FFM. REE and T(3) also increased (+9.3% and +33.3% respectively) at unchanged TSH and T(4). There was a highly significant association between weight gain-induced changes in T(3) and changes in adjusted REE (r = 0.78, P < 0.001, based on Pearson's correlation). An increase in plasma T(3) concentrations of 1.8 pmol/l could explain an increase in REE of 0.6 MJ/day (that is, a 32% increase in T(3) was associated with a 13% increase in REE).

CONCLUSIONS

Our data provide evidence that the low T(3) concentrations add to metabolic adaptation in underweight patients with AN. During weight gain, increases in T(3) are associated with increases in REE, which is independent of FFM. Both results are evidence for a physiologic role of T(3) in modulation of energy expenditure in humans.

High serum leptin levels subsequent to weight gain predict renewed weight loss in patients with anorexia nervosa

It has repeatedly been shown that high serum leptin levels at target weight ensue from therapeutically induced weight gain in patients with anorexia nervosa (AN). It was hypothesized that elevated leptin levels may be an important factor underlying the difficulties of maintaining the target-weight in AN patients after re-feeding. The aim of this study was to examine if serum leptin levels at discharge from inpatient treatment predict renewed weight loss within 2 months after discharge and upon a 1 yr follow-up. Univariate variance analysis (ANOVA) revealed that 60% (cor. R2=0.60, P=0.002) of the variance in the BMI standard deviation score (BMI-SDS) 2 months after discharge was explained by the model consisting of the independent variables lg10 leptin levels at discharge (P=0.019) and at admission (P=0.069) and BMI-SDS at admission (P=0.002) and delta BMI between admission and discharge (P=0.047). Similarly, 60% (cor. R2=0.60, P=0.005) of the variance in BMI-SDS 1 yr after discharge was explained by lg10 leptin levels at discharge (P=0.046) and at admission (P=0.052) and BMI-SDS at admission (P=0.008) and 2 months after discharge (P=0.007) and delta BMI between admission and discharge (P=0.933). Patients with a poor outcome after 1 yr (n=9, ANCOVA, group: descriptive P=0.041), but not recovered patients (n=9, P=0.649), had lg10 leptin levels at discharge higher than those of controls when adjusted for BMI and % body fat at discharge. In conclusion, high serum leptin levels at discharge from inpatient treatment may indicate a risk for renewed weight loss and an unfavorable 1 yr outcome in AN.

Anorexia nervosa medical issues

Anorexia nervosa is an increasingly common chronic psychiatric disorder with a multitude of medical complications. Most of these complications are reversible if there is timely restoration of body weight. A few of them, particularly osteoporosis, refeeding complications, and cardiac arrhythmia, are potentially much more serious. In the end, a multidisciplinary team approach with input from a primary care provider who is familiar with these medical sequelae, together with psychiatric and dietary expertise, can effectuate a successful outcome.

Terapia nutricional na anorexia e bulimia nervosas

A alimentação e a dieta têm um importante papel no desenvolvimento e manutenção dos transtornos alimentares. Portanto, devem ser levados em consideração nos programas de tratamento dessas condições clínicas. Pacientes com transtornos alimentares apresentam importantes restrições dietéticas, padrões alimentares inadequados e hábitos errôneos devido a uma série de falsos mitos e crenças e a uma sensação de incompetência para lidar com o alimento. Tais alterações podem levar a mudanças em seu estado nutricional, que necessita de cuidados dietéticos específicos, como reabilitação nutricional e orientação sobre dieta adequada. Além disto, o aconselhamento nutricional é necessário para esclarecer e desmistificar crenças inadequadas e para estabelecer uma adequada relação com o alimento.

Research on energy expenditure in individuals with eating disorders: a review

OBJECTIVE

This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED).

METHOD

Individual studies are reviewed and their results summarized.

RESULTS

The most consistent finding is a reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters.

DISCUSSION

The ability to measure REE reliably and cost-effectively may aid in the refeeding of patients with AN in whom REE is reduced. Changes in individuals with BN and BED have yet to be consistently identified.

Research on energy expenditure in individuals with eating disorders: a review

OBJECTIVE

This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED).

METHOD

Individual studies are reviewed and their results summarized.

RESULTS

The most consistent finding is evidence of reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters.

DISCUSSION

The ability to reliably and cost-effectively measure REE may aid in the refeeding of patients with AN where REE is reduced. Changes in BN and BED subjects have yet to be identified consistently.

Body composition changes in patients with anorexia nervosa after complete weight recovery

OBJECTIVE

To assess body composition changes occurring in female anorectic patients after complete weight recovery.

DESIGN

Longitudinal study.

SUBJECTS

: Ten female patients with anorexia nervosa (age at baseline: 19.7+/-5.8 y) were studied both when undernourished (body mass index, BMI 14.8+/-1.3 kg/ m(2)) and after the achievement of a BMI >18.5 kg/m(2). The control group comprised 18 well-nourished women (age 20.1+/-4.4 y; BMI 19.0-23.0 kg/ m(2)).

INTERVENTIONS

Fat mass and fat-free mass were determined by dual-energy X-ray absorptiometry. Skinfold thicknesses and circumferences were also measured. Arm muscle area and arm fat area were calculated by standard formulas.

RESULTS

The undernourished patients had lower fat-free mass, fat mass, skinfold thicknesses and circumferences. After refeeding, fat mass represented 25-71% (mean 56%) of the mass regained, this percentage being directly related to the extent of weight gain. The increases in skinfolds and circumferences depended upon the site considered and were correlated to a various extent with those in weight or BMI. Skinfolds at biceps and abdominal sites and the waist-to-hip ratio remained significantly higher, whereas arm muscle circumference was significantly lower, in the refed group than in the control one.

CONCLUSION

The percentage of fat in the weight regained by refed female anorectic patients was directly related to the extent of body mass increase. Refed anorectic patients appear to preferentially regain fat in the abdominal and triceps regions. Abnormalities in skinfolds (at biceps and abdominal sites), arm muscle area and waist-to-hip ratio still persist in refed anorectic patients in comparison to control healthy controls.

A one-year follow-up study in anorexia nervosa. Dietary pattern and anthropometrical evolution

OBJECTIVE

To find out the modifications and the interrelationships between the energy and macronutrient intakes and anthropometric measurements of a group of anorexia nervosa patients (ANP), with homogenous diagnosis, age and treatment, during a 1 y follow-up.

DESIGN

Longitudinal study design.

SUBJECTS

Fourteen restricting-type ANP in the adolescent age (11-21 y) were recruited for the study and evaluated at four time intervals during 1 y of multidisciplinary treatment: (a) on admission (AN0); (b) after 1 month (AN1); (c) after 6 months (AN6); (d) after 1 y (AN12).

MEASURES

Energy and macronutrient composition of the diet (48 h recall) and anthropometric measurements including skinfold thickness.

RESULTS

Mean weight and BMI were under the 3rd percentile in AN0. All anthropometrical parameters increased significantly in AN1 compared to AN0 and did not change in AN6 and AN12. Energy and macronutrient intakes increased significantly in AN1. The dietary changes were not maintained in the subsequent time intervals and there was an overall tendency to turn back to AN0 results. Energy intake adequacy to Spanish Recommended Intakes (RI) showed only an acceptable ratio in AN1 (94% RI); however, a preserved protein intake was found throughout the study (mean intakes between 128.5% and 230.0% RI). Negative correlations were found at AN12 between size of arm's subcutaneous fat stores and energy and macronutrient intakes.

CONCLUSION

In this 1 y follow-up study the decrease in the intake of energy and macronutrients after discharge seems to be related to anthropometric evolution, so that a return to restrictive eating behaviour had occurred in those subjects who had reached the highest values in their subcutaneous fat stores, probably related to dissatisfaction with self-body image.

The prediction of basal metabolic rate in female patients with anorexia nervosa

OBJECTIVE

To evaluate in female patients with anorexia nervosa the accuracy of a specific predictive formula for basal metabolic rate (BMR) already proposed in the literature and to derive a new disease-specific equation with the same purpose.

DESIGN

Cross-sectional study.

SUBJECTS

One-hundred and twenty adolescent girls (<18 y) and young-adult women (18-30 y) with anorexia nervosa.

MEASUREMENTS

BMR was determined by indirect calorimetry or predicted according to the Schebendach formula, which was specifically derived for anorexia nervosa.

RESULTS

On average the Schebendach formula performed well in the adolescent group but not in the young-adult group. The range including 95% of the predicted-measured differences was in both cases wider than 2000 kJ/day. In the young-adult patients the accuracy of the prediction was also related to age and body mass index. Weight and age (but not height or body mass index) emerged as predictors of BMR in the sample as a whole, and only weight when the two age groups were considered separately, thus leading to three different equations. The intercepts of these regression lines were very close and not significantly different from zero while their standard error of estimate was 500-550 kJ/day.

CONCLUSION

The Schebendach formula is not very accurate in estimating the BMR of female anorectic patients. Moreover, in this group the relationship between BMR and weight was altered. The predictive formulas proposed by the present study have a reasonable prediction power.

Body composition of anorexia nervosa patients assessed by underwater weighing and skinfold-thickness measurements before and after weight gain

BACKGROUND

Weight restoration is a crucial element in the treatment of patients with anorexia nervosa. Therefore, the validity of different methods for measuring body composition is important.

OBJECTIVE

We tested the concurrent validity of hydrodensitometry (underwater weighing) and anthropometry (12 skinfold thicknesses) and assessed body composition and subcutaneous fat before and after a refeeding program and a multifaceted program of therapy in a specialized inpatient unit for eating disorders.

DESIGN

The body composition of a large sample of anorexia nervosa patients (97 restricting type, 33 binging-purging type) was studied by using 2 methods both before and after weight gain. We applied a behavioral contract for weight restoration with a minimum weekly gain of 700 g and a maximum of 3 kg. Bland-Altman analysis of agreement, Pearson correlation analysis, t tests, and analysis of covariance were used.

RESULTS

There was good agreement between the results obtained by underwater weighing and by skinfold-thickness measurement (r = 0.76, P < 0.001); the results produced by the 2 methods did not differ significantly. On average, a significant weight gain (11.9 kg) was observed, composed of 6.6 kg fat and 5.3 kg fat-free mass.

CONCLUSIONS

Body fat estimation by skinfold-thickness equation appeared to be as accurate as underwater weighing. The refeeding program led to a significant increase in body weight, of which 55.5% was body fat. The mean ratio of fat-free mass to fat mass at the end of the treatment was 3.4:1.

Altered energy metabolism in anorexia nervosa

Optimal nutritional rehabilitation of anorexia nervosa requires more information concerning actual energy and substrate requirements. To this end, indirect calorimetry was performed in female patients (n=34, age 20.9+/-1.2 yr, body mass index [BMI] 15.6+/-0.2 kg/m(2); mean+/-SEM) soon after commencement of refeeding and at the time of discharge from hospital (n=18, BMI 19.0+/-0.3 kg/m(2)). Healthy female controls (n=18, age 24.6+/-1.3 yr, BMI 21.6+/-0.6 kg/m(2)) were also tested. Resting energy expenditure (REE) and respiratory quotient (RQ) were measured in the fasting state, followed by diet-induced thermogenesis (DIT) and RQ over a 4 h period following a 100 g oral glucose load. Compared with post-refeeding patients and controls, pre-refeeding patients had a high basal RQ and a low REE, with a paradoxically higher DIT (13.2+/-0.9% of REE vs. 8.3+/-1.2% and 8.6+/-0.9% in post-refeeding patients and controls, respectively). RQ values in pre-refeeding patients exceeded unity following the glucose load, probably reflecting net lipogenesis, whereas in the post-refeeding patients, post-glucose RQ was similar to that of controls, suggesting premature curtailment of lipogenesis. These data demonstrate energy wasting in emaciated patients with anorexia nervosa. Biological repair processes could account for disproportionate energy loss early in refeeding and there may be some later impediment to full restoration of fat stores.

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations

BACKGROUND

Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance.

OBJECTIVE

The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN).

DESIGN

Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay.

RESULTS

The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003).

CONCLUSIONS

BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.

Resting energy expenditure of children attending a rehabilitation programme following head injury

STATEMENT OF PURPOSE

Increased resting energy expenditure following head injury is well documented, but whether this increase extends into rehabilitation and whether this is affected by changes in body composition have not been studied. The aim of this study was to determine whether children attending a rehabilitation program following head injury had altered energy expenditure and body composition.

METHODS

Measurements of resting energy expenditure by indirect calorimetry were performed in 21 head injured children (mean age 10.2 +/- 3.8 years). Measurement of body composition was performed using total body potassium.

RESULTS

Measured resting energy expenditure values were widely distributed, ranging from 52.3-156.4% of predicted values, yet the mean percentage predicted using Schofield weight, Schofield weight and height and World Health Organization predictive equations were 97.5%, 97.4% and 98.6%, respectively. Mean percentage of expected total body potassium for weight, height and age for head injured children were 85.1 +/- 15.5%, 89.1 +/- 14.1% and 86.9 +/- 15.9%, thus all showed significant depletion.

CONCLUSIONS

During rehabilitation, using predictive equations to estimate resting energy expenditure in this group revealed a small bias on average but very large bias at the individual level. Head injured children had altered resting energy expenditure and body composition.