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

The effect of flaxseed intake on appetite reduction: A systematic review of randomized clinical trials

Appetite control has attracted many scientists' attention recently since it can lead to weight management and the prevention of further metabolic disorders. Many studies have been carried out to assess the effect of flaxseed on satiety perception but the results are controversial. This study aims to review these results comprehensively. PubMed/Medline, Web of Science, Scopus, and Cochrane databases were searched for related papers on June 2021. The searched keywords for appetite were: visual analog scale, appetite, desire to eat, satiation, satiety, hunger, fullness, and for Flaxseed they were: flax, flax*, linseed*, lignin*, Linseed Oil, flaxseed, ground flaxseed, flaxseed oil, and Linum usitatissimum. The 13 included studies were inconsistent in results and some of them found no significant effect of flaxseed on the considered outcomes. However, three studies revealed a significant reduction in hunger perception as well as appetite. Moreover, two studies found a decreasing effect on prospective consumption. Three studies observed a positive significant effect on fullness and satiety. Although there are a limited number of documents related to the effect of flaxseed on appetite perception, or its equivalent terms, the available studies suggest the potential role of flaxseed in decreasing appetite and hunger.

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.

Hypothesizing Nutrigenomic-Based Precision Anti-Obesity Treatment and Prophylaxis: Should We Be Targeting Sarcopenia Induced Brain Dysfunction?

Background: The United States Centers for Disease Control and Prevention (CDC) estimates a total obesity rate of 30% for 12 states and a 20% obesity rate nationwide. The obesity epidemic continues to increase in spite of preventative measures undertaken worldwide. Pharmacological treatments promise to reduce total fat mass. However, medications may have significant side effects and can be potentially fatal. Data Retrieval: This brief review, based on a PUBMED search of the key terms "Obesity" and" Sarcopenia," will present evidence to corroborate the existence of Reward Deficiency Syndrome (RDS) in obesity and the involvement of catecholaminergic pathways in substance seeking behavior, particularly as it relates to carbohydrates cravings. Expert Opinion: The genetic basis and future genetic testing of children for risk of aberrant generalized craving behavior are considered a prevention method. Here we present evidence supporting the use of precursor amino acid therapy and modulation of enkephalinase, MOA, and COMT inhibition in key brain regions. Such treatments manifest in improved levels of dopamine/norepinephrine, GABA, serotonin, and enkephalins. We also present evidence substantiating insulin sensitivity enhancement via Chromium salts, which affect dopamine neuronal synthesis regulation. We believe our unique combination of natural ingredients will influence many pathways leading to the promotion of well-being and normal healthy metabolic functioning. Sarcopenia has been shown to reduce angiogenesis and possible cerebral blood flow. Exercise seems to provide a significant benefit to overcome this obesity-promoting loss of muscle density. Conclusion: Utilization of proposed nutrigenomic formulae based on coupling genetic obesity risk testing promotes generalized anti-craving of carbohydrates and can inhibit carbohydrate bingeing, inducing significant healthy fat loss and relapse prevention.

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.

The relationship between dietary intake and energy availability, eating attitudes and cognitive restraint in students enrolled in undergraduate nutrition degrees

The aim of this research was to explore the relationship of total energy and macronutrient intake, energy balance and energy availability to eating attitudes and cognitive restraint in students enrolled in undergraduate nutrition degrees. Energy and micronutrient intake was assessed in 63 students (n = 50 nutrition, and n = 13 occupation therapy degrees; n = 51 females, n = 12 males) using three 24-h dietary recalls. Energy requirements were calculated based on measured resting metabolic rate, estimated exercise energy expenditure, and dietary induced thermogenesis. Body composition was assessed using dual energy x-ray absorptiometry. Eating attitudes and cognitive restraint were measured using previously validated tools. Eighteen percent of nutrition students were classified as having low energy availability (<30 kcal kgFFM^-1d^-1) and 38% were in negative energy balance. Eating attitudes and cognitive restraint were not associated with total energy or macronutrient intake. However, female nutrition students with high cognitive restraint had greater exercise energy expenditure and thus lower energy availability than those with low cognitive restraint (371 (302) kcal d^-1 compared to 145 (206) kcal d^-1, P < 0.01, and 35 (7) kcal d^-1 compared to 41 (10) kcal d^-1 of fat free mass, P = 0.005). Additionally, in females, disordered eating attitudes and cognitive restraint negatively correlated with energy availability (r_s = -0.37, P = 0.02 and r_s = -0.51, P < 0.01 respectively). There were no differences in outcomes between nutrition and non-nutrition students. The current study suggests that those students with disordered eating attitudes and cognitive restraint may be controlling their energy balance through exercise, as opposed to restricting food intake.

Association between resting energy expenditure, psychopathology and HPA-axis in eating disorders

AIM: To investigate the complex relationships between resting energy expenditure (REE), eating psychopathology, and Hypothalamus Pituitary Adrenal axis functioning in patients with eating disorders.

METHODS: The study was designed as a cross-sectional survey, and it was planned by the Clinic for Eating Disorders of the University of Florence (Italy). The protocol was approved by the Ethics Committee of the Institution. Twenty two anorexia nervosa and twenty one Bulimia Nervosa patients were assessed by means of a clinical interview and the structured clinical interview for diagnostic and statistical manual of mental disorders, fourth edition. Eating attitudes and behaviour were specifically investigated by means of the eating disorder examination questionnaire (EDE-Q). Patients were also evaluated by means of the symptom checklist (SCL 90-R), REE was measured by means of indirect calorimetry, and blood cortisol morning levels were evaluated.

RESULTS: Both anorexia nervosa and bulimia nervosa patients showed a reduced REE as compared with predicted REE. Body mass index (BMI) was positively associated with resting energy expenditure in Bulimics, whereas a strong, negative association between BMI and REE was observed in Anorectics. The pattern of associations between variables supported a mediation model, where shape concern accounted for variations in REE and cortisol levels (mediator), and variations in the mediator significantly accounted for variations in REE. When these associations where taken into account together, the relationship between shape concern and REE was no longer significant, whereas the association between cortisol levels and REE retained its significance, showing strong evidence for a single, dominant mediator. Anorectics and Bulimics showed an opposite pattern of association between BMI and REE. In Anorectics only, a higher REE was associated with a more severe eating disorder specific psychopathology, and cortisol levels represent a possible mediating factor for this relationship.

CONCLUSION: The data supported a mediation model where cortisol levels mediated the relationship between eating psychopathology (concern about body shape) and REE.

Circulating interleukin 6 and soluble forms of its receptors in relation to resting energy expenditure in women with anorexia nervosa

CONTEXT

Anorexia nervosa (AN) is an eating disorder, resulting in sustained low weight and marked decrease in fat mass. Interleukin 6 (IL-6) may play a role in appetite, energy expenditure and body weight control. IL-6 acts through binding with membrane receptor (IL-6R) and activates glycoprotein 130 (gp130) signalling. Both IL-6R and gp130 are present in the blood in the soluble forms (sIL-6R and sgp130 respectively). sIL-6R sensitizes cells towards IL-6, whereas sgp130 inhibits gp130 signalling.

OBJECTIVE

To estimate circulating IL-6/sIL-6R/sgp130 system and its relationships with body weight and resting energy expenditure (REE) in AN women.

PATIENTS

We examined 19 women with AN and 27 healthy normal-weight female controls.

MEASUREMENTS

Indirect calorimetry and the measurement of serum IL-6, sIL-6R and sgp130 concentrations were performed in all the subjects.

RESULTS

REE was decreased in AN women (P < 0·001). Serum IL-6 was higher in AN women in comparison with control group (P = 0·005). Serum sIL-6R was lower (P = 0·009) and serum sgp130 was higher (P = 0·004) in AN women in comparison with controls. IL-6 and sIL-6R were related to REE in the entire study population (r = -0·54, P < 0·001 and r = 0·48, P = 0·001 respectively) and in AN group (r = -0·54, P = 0·024 and r = 0·60, P = 0·011 respectively).

CONCLUSIONS

Increased IL-6 in AN seems to be compensated by the changes in sIL-6R and sgp130, which are directed towards inhibition of IL-6 action. The balance between these factors might play a role in the regulation of energy expenditure in AN.

Impact of exercise on energy metabolism in anorexia nervosa

BACKGROUND

Excessive physical activity is one of the most paradoxical features of anorexia nervosa (AN). However, there is individual variation in the degree of physical activity found in AN-patients. As a result, marked differences in energy expenditure may be expected. Furthermore, exercise has a positive impact on a variety of psychological disorders and the psychopathology may be different in AN displaying high exercise levels versus AN displaying low exercise levels. We analyzed the energy metabolism and psychological data in low-level exercise and high-level exercise AN-patients compared with healthy, age matched controls.

RESULTS

REE was decreased in AN-patients compared with controls but not when adjusted for body surface area or lean body mass. No differences in TDEE between AN- patients and controls were observed. Subgroup analyses showed that the percentage of high-level AN- exercisers was higher compared with controls. This subgroup had increased resting EE, total daily EE and scored higher on depression and the EDI-item "Drive for thinness" compared with low-level AN-exercisers.

CONCLUSIONS

We identified a significant subgroup of high-level AN-exercisers (66%) with consecutive increased energy requirements. An easy way for clinicians to assess the amount of exercise before and in the course of treatment is a single question in the established Eating Disorder Inventory-SC (EDI-SC).

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.

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.

Metabolic assessment of menstruating and nonmenstruating normal weight adolescents

OBJECTIVE

Resumption of menses (ROM) is a key indicator of recovery in AN, but patients may remain amenorrheic despite weight restoration. The objective of this study is to better understand the mechanism of amenorrhea in patients with eating disorders.

METHOD

A retrospective chart review was conducted of 382 normal weight adolescents with a history of anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified, who had been referred for indirect calorimetry tests. Resting energy expenditure (REE) was compared between amenorrheic (n = 60) and regularly menstruating females (n = 121).

RESULTS

Participants with amenorrhea had a mean REE of 1,103 kcal/24 h (79% predicted), whereas participants who were menstruating regularly had a mean REE of 1,217 kcal/24 h (85% predicted; p = 0.001). The amenorrheic group was found to be at a lower mean body weight (53.7 +/- 5.6 kg vs. 57.5 +/- 7.4 kg; p < or = 0.001), at a lower percent ideal body weight (98.5 +/- 8.3% vs. 102.8 +/- 10.2%; p = 0.005), and at a lower BMI (20.5 +/- 1.7 vs. 21.5 +/- 2.2; p = 0.002).

DISCUSSION

This study highlights that amenorrheic participants with a history of eating disorders who are at normal body weight are hypometabolic, suggesting an adaptive response to dietary restriction.

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.

The 'drive for activity' and "restlessness" in anorexia nervosa: potential pathways

This paper discusses the hypothesis that a 'drive for activity" in the presence of physiological and endocrine changes consistent with starvation is a characteristic symptom of acute anorexia nervosa (AN). This 'drive for movement', along with alertness and lack of fatigue, so unlike the motor slowing and loss of energy observed in simple starvation has been recognized in AN throughout history, but has received little attention in the past fifty years. Clinical reports and experimental evidence suggest that 'restlessness' and a 'drive for activity' vary in intensity, they appears to be starvation-dependent and to wane with food intake. Central nervous system (CNS) systems known to be involved in mediating activity and arousal levels that are altered by the negative energy expenditure in AN are reviewed. Among these, the corticotropin-releasing hormone (CRH) system, the melanocyte stimulating hormone/agouti-related protein (MSH/AGRP) system and the norepinephrine/epinephrine (NE/EPI) and dopamine (DA) system may contribute to the 'drive for activity' and alertness in AN. AN appears to represent a disorder of gene/environment interaction. Future research will reveal whether in individuals predisposed to AN, the 'drive for activity' reflects the reactivation of mechanisms important in food scarcity, controlled by one or more evolutionary conserved genes including those regulating foraging behavior. Recognition of the 'drive for activity' as a diagnostic symptom of AN and its assessment prior to re-nutrition would permit clarification of its role in the etiology of AN.

Glucose tolerance predicts short-term refeeding outcome in females with anorexia nervosa

OBJECTIVE

Little is known about biologic predictors of refeeding outcome in anorexia nervosa (AN). Because nutritional status mirrors glucose metabolism during an oral glucose tolerance test (OGTT) in AN, this study investigated whether pretreatment glucose response patterns during the OGTT might be associated with refeeding progress in patients with AN.

METHODS

Sixty-four female patients with anorexia (33 restrictors and 31 binge/purgers) and 13 healthy control subjects underwent an OGTT before nutritional rehabilitation, including desensitization to fear of energy intake of 1000 to 1600 kcal/day. Patients were divided into flat-type responders, impaired glucose tolerance (IGT)-type responders, and normal-type glucose responders. Daily energy intake, weekly weight gain, and the duration of desensitization period were evaluated until the 12th week.

RESULTS

The patients with anorexia consisted of 20 flat-type, 21 IGT-type, and 23 normal- type responders. Normal-type responders required a shorter time to complete the desensitization period than other responders (p = .003 for restrictors, p < .001 for binge/purgers). In terms of refeeding progress, significant group effects for daily energy intake and weekly weight gain were evident in restrictors (p = .006, p = .028, respectively) and binge/purgers (p < .001, p = .003, respectively); normal-type responders showed good refeeding progress compared with other responders in both AN subtypes.

CONCLUSIONS

The present study found a close relationship between pretreatment glucose responses, therapeutic progress of desensitization to fear of energy intake, and refeeding progress in both AN subtypes. Our findings suggest that glucose tolerance may be a useful predictor of short-term refeeding outcome in this disorder.

Factors associated with the increase in resting energy expenditure during refeeding in malnourished anorexia nervosa patients

BACKGROUND

In malnourished anorexia nervosa (AN) patients, body-weight gain during refeeding is slowed by an increase in resting energy expenditure (REE).

OBJECTIVE

The objective of the study was to identify factors associated with the increase in REE during refeeding.

DESIGN

Before and 8, 30, and 45 d after the beginning of refeeding, REE was studied by indirect calorimetry in 87 female AN patients [x +/- SD age: 23.4 +/- 7.9 y; body mass index (in kg/m2) 13.2 +/- 1.3]. Energy intake, body composition (by bioelectrical impedance analysis), physical activity, smoking behavior, abdominal pain, anxiety, depressive mood, serum thyrotropin and thyroid hormone, and urinary catecholamines were measured. REE was also evaluated in 18 patients after 1 y of recovery.

RESULTS

By day 8, REE increased from 3.84 +/- 0.6 to 4.36 +/- 0.59 MJ/d (P < 0.01). This increase (13.4%) was significantly (P <0.01) greater than that expected on the basis of the increase in fat-free mass (FFM; 1.6%). Thereafter, the ratio of REE to FFM remained high and, in multivariate analysis, was significantly related to 4 factors: energy intake (P <0.01), anxiety (P <0.01), abdominal pain (P <0.05), and depressive mood (P <0.05). The ratio also increased significantly with physical activity (P <0.01) and cigarette smoking (P <0.02). This rise in REE leveled off after recovery from AN.

CONCLUSION

In AN patients, the rise in REE observed during refeeding was independently linked to anxiety level, abdominal pain, physical activity, and cigarette smoking, and it contributed to resistance to weight gain.

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

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

Altered 5-HT(2A) receptor binding after recovery from bulimia-type anorexia nervosa: relationships to harm avoidance and drive for thinness

Several lines of evidence suggest that a disturbance of serotonin neuronal pathways may contribute to the pathogenesis of anorexia nervosa (AN) and bulimia nervosa (BN). This study applied positron emission tomography (PET) to investigate the brain serotonin 2A (5-HT(2A)) receptor, which could contribute to disturbances of appetite and behavior in AN and BN. To avoid the confounding effects of malnutrition, we studied 10 women recovered from bulimia-type AN (REC AN-BN, > 1 year normal weight, regular menstrual cycles, no binging, or purging) compared with 16 healthy control women (CW) using PET imaging and a specific 5-HT(2A) receptor antagonist, [18F]altanserin. REC AN-BN women had significantly reduced [18F]altanserin binding potential relative to CW in the left subgenual cingulate, the left parietal cortex, and the right occipital cortex. [18F]altanserin binding potential was positively related to harm avoidance and negatively related to novelty seeking in cingulate and temporal regions only in REC AN-BN subjects. In addition, REC AN-BN had negative relationships between [18F]altanserin binding potential and drive for thinness in several cortical regions. In conclusion, this study extends research suggesting that altered 5-HT neuronal system activity persists after recovery from bulimia-type AN, particularly in subgenual cingulate regions. Altered 5-HT neurotransmission after recovery also supports the possibility that this may be a trait-related disturbance that contributes to the pathophysiology of eating disorders. It is possible that subgenual cingulate findings are not specific for AN-BN, but may be related to the high incidence of lifetime major depressive disorder diagnosis in these subjects.