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

Metabolic profile in women with bulimia nervosa or binge-eating disorder before and after treatment: secondary analysis from the randomized PED-t trial

PURPOSE

Chaotic eating and purging behavior pose a risk to the metabolic health of women with bulimia nervosa (BN) and binge-eating disorder (BED). This study reports on one-year changes in blood markers of metabolic health and thyroid hormones in women with BN or BED attending two different treatments.

METHODS

These are secondary analyses from a randomized controlled trial of 16-week group treatment of either physical exercise and dietary therapy (PED-t) or cognitive behavior therapy (CBT). Blood samples collected at pre-treatment, week eight, post-treatment, and at 6- and 12-month follow-ups were analyzed for glucose, lipids (triglycerides (TG), total cholesterol (TC), LDL cholesterol (LDL-c), HDL cholesterol (HDL-c), apolipoprotein A (ApoA) and apolipoprotein B (ApoB) lipoproteins), and thyroid hormones (thyroxine (T4), thyroid stimulating hormone (TSH), and thyroperoxidase antibodies).

RESULT

The average levels of blood glucose, lipids and thyroid hormones were within the recommended range, but clinical levels of TC and LDL-c were detected in 32.5% and 39.1%, respectively. More women with BED compared with BN had low HDL-c, and a larger increase over time in TC and TSH. No significant differences occurred between PED-t and CBT at any measurement. Exploratory moderator analyses indicated a more unfavorable metabolic response at follow-up among treatment non-responders.

CONCLUSION

The proportion of women with impaired lipid profiles and unfavorable lipid changes, suggests active monitoring with necessary management of the metabolic health of women with BN or BED, as recommended by metabolic health guidelines.

LEVEL OF EVIDENCE

Level I: Evidence obtained from a randomized, experimental trial.

TRIAL REGISTRATION NUMBER

This trial was prospectively registered in the Norwegian Regional Committee for Medical and Health Research Ethics on December 16, 2013, with the identifier number 2013/1871, and in Clinical Trials on February 17, 2014, with the identifier number NCT02079935.

Evaluation of a short protocol for indirect calorimetry in females with eating disorders and healthy controls

BACKGROUND AND AIMS

To enable clinicians to identify the clinical picture and treatment progress and to adjust eating plans according to personal energy needs, it is important to know the patient's correct resting metabolic rate (RMR). Indirect calorimetry (IC) is the preferred method for assessment of RMR, but long duration of measurement increases the load on the patients, and reduces the effectiveness in clinical and scientific settings. Further; not all patients reach a valid RMR according to the suggested best practice protocol, with 5 min of steady state (SS) where respiratory gas volume exchange varies less than 10%. The aim of this study was to evaluate the possibility for an abbreviated RMR protocol and SS criterion.

METHODS

Forty two women diagnosed with bulimia nervosa or binge eating disorder (eating disorder group, ED), originally recruited for an outpatient treatment study, and 26 age and gender matched healthy controls (HC) were studied during a single, prolonged IC measurement. Participants rested for 10 min in supine position wearing a two-way breathing facemask, before a continuous measurement period of 20 min. Results from a standard 5 min SS criterion was compared to an abbreviated 3 min SS criterion. Both SS-criteria were evaluated through three different SS protocols (<10% variation in respiratory gas exchange), being: 1) measurement during the first 3 or 5 min, 2) measurement after discarding the first 5 min, and 3) the lowest identified RMR during the 20 min of measurement.

RESULTS

About 50% of the participants reached an early SS in both the defined SS minute criteria. Participants reaching a valid SS throughout the 20 min of measurement increased from ∼90% to 100% with an abbreviated 3 min SS. With a 5 min SS criterion, the median (range) RMR for the 3 protocols were 1639.9 (1239.2), 1508.8 (1457.6) and 1500.6 (1328.8) respectively for the ED group, and 1702.2 (1239.4), 1608.4 (1076.4) and 1594.8 (1029.2) respectively for the HC group, (p > 0.05 for all between-group analysis). With a 3 min SS criterion, the median (range) RMR were 1533.6 (1298.2), 1461.2 (1406.1), and 1395.8 (1447.3) respectively for the ED group and 1681.7 (1332.4), 1613.7 (1266.0) and 1523.1 (1050.3), respectively for the HC group, (p > 0.05 for all between-group analysis). Lowest measured RMR was different compared to the other two SS protocols in both the ED- and the HC group, and for both the 5 min- and the 3 min SS criteria, respectively (p < 0.04). Furthermore, a SS of 3 min resulted in lower RMR compared to 5 min SS (p < 0.00) and an increased number of participants classified as hypo-metabolic (RMRmeasured/RMRcalculated < 0.9).

CONCLUSIONS

An abbreviated measurement protocol to identify the lowest RMR using IC was not successful. Abbreviating the SS criteria from 5 to 3 min, resulted in a lower RMR, hence encouraging further examination of the validity of shorter SS criterion than practiced today. Registered in Clinical Trials by id-number NCT02079935, and approved by the Norwegian Regional Committee for Medical and Health Research Ethics with id-number 2013/1871. The trial in which control persons were recruited, is approved by the Norwegian Regional Committees for Medical and Health Research Ethics with the id-number 2016/1718, and prospectively registered in Clinical Trials with the id-number NCT03007459.

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.

Weight suppression is a robust predictor of outcome in the cognitive-behavioral treatment of bulimia nervosa

This study examined weight suppression (difference between highest premorbid weight and pretreatment weight) as a predictor of outcome in 188 outpatients with bulimia nervosa enrolled in a cognitive-behavioral therapy intervention. Participants who dropped out of treatment had significantly higher levels of weight suppression than treatment completers. Of participants who completed treatment, those who continued to engage in binge eating or purging had significantly higher levels of weight suppression than those who were abstinent from bingeing and purging. Results did not change when body mass index, dietary restraint, weight and shape concerns, or other relevant variables were controlled. Relinquishing bulimic behaviors and adopting normal eating patterns may be most feasible for patients who are closest to their highest premorbid weights.

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.

Weight suppression predicts weight gain during inpatient treatment of bulimia nervosa

Bulimic individuals typically lose a substantial amount of weight in the process of developing their disorder. Such weight suppression (WS) may be behaviorally and metabolically problematic. The present study tested the hypothesis that WS would predict weight gain during the inpatient hospitalization of 146 bulimia nervosa-spectrum inpatients. WS represented the difference (M=12.0 kg) between highest weight ever and current body weight. Controlling for length of stay and current dieting (EAT-D scores), high levels of WS predicted greater weight gain. Furthermore, WS and admission BMI independently predicted weight gain when entered together in a regression analysis. Weight gain was also related to clinical improvement. These findings suggest that weight suppression, independently of current dieting status, may produce psychobiological pressures toward weight gain and could complicate the treatment of bulimia nervosa.

Medical assessment of adolescent girls with eating disorders: an evaluation of symptoms and signs of starvation

AIM

To investigate the prevalence of symptoms and signs related to starvation at the initial examination of adolescent girls with eating disorders (ED).

METHODS

Two hundred and eleven girls with eating disorders recruited for a multicentre research and evaluation programme of six specialist eating disorder services in Sweden have been studied. The presence or absence of 12 symptoms, reported by the patients, and 16 signs, observed by the examiners, were registered and related to body weight.

RESULTS

Eleven observed signs--loss of subcutaneous fat, loss of muscle mass, loss of muscular force, dry and scaly skin, brittle nails, dry and brittle hair, lanugo hair, resting pulse <60, systolic blood pressure <110, peripheral hypothermia, and peripheral cyanosis--were related to body weight expressed in standard deviation scores (SDS). When the number of observed signs for each patient was calculated, there was a strong relationship with weight. The odds ratio for having more than two signs was 4.35 (95% CI 2.67-7.04; p = 2.8 x 10(-9) for every one-unit change in weight SDS. Of the symptoms reported by the patients, only three were related to weight. When the number of reported symptoms for each patient was calculated, a relationship with weight was not observed.

CONCLUSION

In adolescent girls with ED, physical signs observed at medical examination can be related to weight. However, reported symptoms are poorly related to weight and may be influenced by other factors. The finding emphasizes the importance of medical assessment at presentation of patients with ED.

Phase angle is a predictor of basal metabolic rate in female patients with anorexia nervosa

The aim of the study was to evaluate the relationship between basal metabolic rate (BMR) and bioelectrical impedance analysis (BIA) in undernourished female patients with anorexia nervosa. Participants were 86 female patients with anorexia nervosa (age 20.8+/-4.7 years; weight 39.3+/-5.2 kg; body mass index 15.4+/-1.6 kg m-2). BMR was measured by indirect calorimetry and single-frequency BIA was determined at 50 kHz on the whole body. The BIA variables considered were resistance, reactance, phase angle and the bioimpedance index (height2/resistance). Fat-free mass was calculated from subcutaneous skin fold thickness. In the study group BMR was 3782+/-661 kJ d-1 while bioimpedance index varied between 27.6 and 49.9 cm2 Omega-1 and phase angle between 2.54 degrees and 6.49 degrees. BMR was significantly correlated with weight, height, body mass index and fat-free mass, and, among BIA variables, with reactance and phase angle. Multiple regression analysis indicated that phase angle was a predictor of BMR not only when solely BIA variables were considered, but also in combination with either weight and age or fat-free mass. In conclusion, phase angle emerged as a strong predictor of BMR in female patients with anorexia nervosa. Nevertheless, further studies are necessary to confirm this finding in other forms of protein energy malnutrition and justify the inclusion of BIA variables in the equations used to predict BMR in the clinical setting.