Characterising illness stages and recovery trajectories of eating disorders in young people via remote measurement technology (STORY): a multi-centre prospective cohort study protocol.

BACKGROUND: Eating disorders (EDs) are serious, often chronic, conditions associated with pronounced morbidity, mortality, and dysfunction increasingly affecting young people worldwide. Illness progression, stages and recovery trajectories of EDs are still poorly characterised. The STORY study dynamically and longitudinally assesses young people with different EDs (restricting; bingeing/bulimic presentations) and illness durations (earlier; later stages) compared to healthy controls. Remote measurement technology (RMT) with active and passive sensing is used to advance understanding of the heterogeneity of earlier and more progressed clinical presentations and predictors of recovery or relapse. METHODS: STORY follows 720 young people aged 16-25 with EDs and 120 healthy controls for 12 months. Online self-report questionnaires regularly assess ED symptoms, psychiatric comorbidities, quality of life, and socioeconomic environment. Additional ongoing monitoring using multi-parametric RMT via smartphones and wearable smart rings ('Oura ring') unobtrusively measures individuals' daily behaviour and physiology (e.g., Bluetooth connections, sleep, autonomic arousal). A subgroup of participants completes additional in-person cognitive and neuroimaging assessments at study-baseline and after 12 months. DISCUSSION: By leveraging these large-scale longitudinal data from participants across ED diagnoses and illness durations, the STORY study seeks to elucidate potential biopsychosocial predictors of outcome, their interplay with developmental and socioemotional changes, and barriers and facilitators of recovery. STORY holds the promise of providing actionable findings that can be translated into clinical practice by informing the development of both early intervention and personalised treatment that is tailored to illness stage and individual circumstances, ultimately disrupting the long-term burden of EDs on individuals and their families.

Effects of repetitive transcranial magnetic stimulation in children and young people with psychiatric disorders: a systematic review.

Repetitive transcranial magnetic stimulation (rTMS) has demonstrated benefits in adults with psychiatric disorders, but its clinical utility in children and young people (CYP) is unclear. This PRISMA systematic review used published and ongoing studies to examine the effects of rTMS on disorder-specific symptoms, mood and neurocognition in CYP with psychiatric disorders. We searched Medline via PubMed, Embase, PsychINFO via OVID, and Clinicaltrials.gov up to July 2023. Eligible studies involved multiple-session (i.e., treatment) rTMS in CYP (≤ 25 years-old) with psychiatric disorders. Two independent raters assessed the eligibility of studies and extracted data using a custom-built form. Out of 78 eligible studies (participant N = 1389), the majority (k = 54; 69%) reported an improvement in at least one outcome measure of disorder-specific core symptoms. Some studies (k = 21) examined rTMS effects on mood or neurocognition,: findings were largely positive. Overall, rTMS was well-tolerated with minimal side-effects. Of 17 ongoing or recently completed studies, many are sham-controlled RCTs with better blinding techniques and a larger estimated participant enrolment. Findings provide encouraging evidence for rTMS-related improvements in disorder-specific symptoms in CYP with different psychiatric disorders. However, in terms of both mood (for conditions other than depression) and neurocognitive outcomes, evidence is limited. Importantly, rTMS is well-tolerated and safe. Ongoing studies appear to be of improved methodological quality; however, future studies should broaden outcome measures to more comprehensively assess the effects of rTMS and develop guidance on dosage (i.e., treatment regimens).

A randomised controlled feasibility trial of intermittent theta burst stimulation with an open longer-term follow-up for young people with persistent anorexia nervosa (RaISE): Study protocol.

OBJECTIVE: We present the protocol of a feasibility randomised controlled trial (RCT) of intermittent theta burst stimulation (iTBS) for young people with anorexia nervosa (AN). Effective first-line psychological therapies exist for young people with AN, but little is known about how to treat those who do not respond. Non-invasive neuromodulation, such as iTBS, could address unmet treatment needs by targeting neurocircuitry associated with the development and/or maintenance of AN. DESIGN: Sixty-six young people (aged 13-30 years) with persistent AN will be randomly allocated to receive 20 sessions of real or sham iTBS over the left dorsolateral prefrontal cortex in addition to their usual treatment. Outcomes will be measured at baseline, post-treatment (1-month post-randomisation) and 4-months post-randomisation (when unblinding will occur). Additional open follow-ups will be conducted at 12- and 24-months post-randomisation. The primary feasibility outcome is the proportion of participants retained in the study at 4-months. Secondary outcomes include AN symptomatology, other psychopathology, quality of life, service utilisation, neurocognitive processes, and neuroimaging measures. DISCUSSION: Findings will inform the development of a future large-scale RCT. They will also provide exploratory data on treatment efficacy, and neural and neurocognitive predictors and correlates of treatment response to iTBS in AN.

Effects of transcranial direct current stimulation in children and young people with psychiatric disorders: a systematic review.

Transcranial direct current stimulation (tDCS) has demonstrated benefits in adults with various psychiatric disorders, but its clinical utility in children and young people (CYP) remains unclear. This PRISMA systematic review used published and ongoing studies to examine the effects of tDCS on disorder-specific symptoms, mood and neurocognition in CYP with psychiatric disorders. We searched Medline via PubMed, Embase, PsychINFO via OVID, and Clinicaltrials.gov up to December 2022. Eligible studies involved multiple session (i.e., treatment) tDCS in CYP (≤ 25 years old) with psychiatric disorders. Two independent raters assessed the eligibility of studies and extracted data using a custom-built form. Of 33 eligible studies (participant N = 517), the majority (n = 27) reported an improvement in at least one outcome measure of disorder-specific symptoms. Few studies (n = 13) examined tDCS effects on mood and/or neurocognition, but findings were mainly positive. Overall, tDCS was well tolerated with minimal side effects. Of 11 eligible ongoing studies, many are sham-controlled RCTs (n = 9) with better blinding techniques and a larger estimated participant enrolment (M = 79.7; range 15-172) than published studies. Although encouraging, the evidence to date is insufficient to firmly conclude that tDCS can improve clinical symptoms, mood, or cognition in CYP with psychiatric disorders. Ongoing studies appear of improved methodological quality; however, future studies should broaden outcome measures to more comprehensively assess the effects of tDCS and develop dosage guidance (i.e., treatment regimens).

'My dad was like "it's your brain, what are you doing?"': Participant experiences of repetitive transcranial magnetic stimulation treatment in severe enduring anorexia nervosa.

OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is a promising emerging treatment for anorexia nervosa (AN). However, to date, patients' views and experiences of this treatment have not been fully explored. To assess these, we integrated a qualitative study into a feasibility randomised controlled trial of rTMS in individuals with severe enduring AN. METHOD: Twenty-nine (of 34) trial participants contributed to this study. Semi-structured interviews were conducted 3-months following the completion of rTMS treatment (4-months post-randomisation), prior to unblinding. Transcripts were analysed using content analysis. RESULTS: rTMS was deemed an acceptable but time-consuming treatment. Many emphasised how their lives had changed to some extent during, but mainly after treatment by making them more positive, open-minded, flexible and willing to try new things in relation to their AN and other aspects of their lives. CONCLUSIONS: These qualitative data will be valuable in shaping participant information, recruitment and planning of future large-scale trials of rTMS in AN. TRIAL REGISTRATION: ISRCTN14329415, registered 23rd July 2015, https://www.isrctn.com/ISRCTN14329415.

Cytokines and Water Distribution in Anorexia Nervosa.

In patients with anorexia nervosa (AN), decreased intracellular (ICW), extracellular (ECW), and total body water (TBW) as well as changes in serum cytokine concentrations have been reported. In this exploratory study, we measured body composition and serum cytokine levels in patients with AN (n = 27) and healthy controls (HCs; n = 13). Eating disorder symptom severity was assessed using the Eating Disorder Examination-Questionnaire (EDE-Q). Body composition was determined by bioimpedance analysis (BIA) which provided information on ICW, ECW, and TBW. Following blood collection, 27 cytokines and chemokines were quantified using multiplex ELISA-based technology: Eotaxin, Eotaxin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon- (IFN-) γ, interleukin- (IL-) 1α, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12/IL-23p40, IL-12p70, IL-13, IL-15, IL-16, IL-17A, interferon γ-induced protein- (IP-) 10, macrophage inflammatory protein- (MIP-) 1α, MIP-1ß, monocyte chemoattractant protein- (MCP-) 1, MCP-4, thymus and activation-regulated chemokine (TARC), TNF-α, and TNF-ß. ICW, ECW, and TBW volumes were significantly lower in patients with AN than in HCs. In the whole sample, GM-CSF, MCP-4, and IL-4 were positively, whereas IFN-γ, IL-6, and IL-10 were negatively associated with all three parameters of body water. In AN participants, we found a statistically significant negative correlation of IL-10 with ICW, ECW, and TBW. Our results suggest an interaction between body water and the cytokine system. Underlying mechanisms are unclear but may involve a loss of water from the gut, kidneys, or skin due to AN-associated inflammatory processes.

The outcomes of mindfulness-based interventions for Obesity and Binge Eating Disorder: A meta-analysis of randomised controlled trials.

BACKGROUND: Mindfulness Based Interventions (MBIs) for weight loss and overeating-related behaviours have recently gained popularity. Previous systematic reviews and meta-analyses included studies of variable quality, which hinders interpretation of results. This meta-analysis examined only randomised controlled trials (RCTs) comparing the efficacy of MBIs with control groups primarily encouraging either dietary or exercise-based behavioural change in individuals with overweight/obesity and/or binge eating disorder (BED). METHODS: Using PRISMA guidelines, we systematically reviewed relevant articles in Medline, Psychinfo and EMBASE. Twelve eligible RCTs were identified, with three random-effects meta-analyses conducted on primary outcome measures of body mass (N = 11), mindfulness (N = 7) and BED symptoms (N = 3). RESULTS: MBIs were more efficacious than control in increasing mindfulness scores and decreasing BED symptoms from pre-to post-treatment. However, they were no more efficacious than control in reducing body mass which may be attributed to variability in the duration of interventions. Based on intervention duration, exploratory cumulative meta-analyses revealed that while shorter interventions (i.e., 6 weeks) showed greater reductions in body mass compared to longer interventions (i.e., 24 weeks), longer interventions led to greater improvements in mindfulness scores and BED symptoms. CONCLUSIONS: These results highlight the potential of MBIs to improve obesity-related behaviours compared to lifestyle interventions, but their effects on short-term weight loss remain unclear. Future research with a rigorous methodology should consider long-term follow-ups including body mass and mindfulness-related outcome measures in order to establish the clinical potential of MBIs.

A longitudinal analysis of cytokines in anorexia nervosa.

OBJECTIVE: Inflammation has been proposed to have a pathophysiological role in anorexia nervosa (AN) and to contribute to the maintenance of the disorder. Longitudinal cytokine research in AN has focused on only a few pro-inflammatory cytokines. We assessed a broad range of cytokines over time in people undergoing specialised treatment for AN. METHOD: We measured serum concentrations of 27 cytokines in people with AN (n = 23). Body mass index (BMI), eating disorder (ED) symptoms and general psychopathology were assessed and blood samples were collected within four weeks of the commencement of specialised ED treatment (baseline) and at 12- and 24-week follow-ups. RESULTS: Both BMI and ED symptoms improved over the assessment period. Linear mixed models showed that log IL-6 decreased between baseline and week 12 assessments. By week 12, log IL-6 values were comparable to levels in healthy individuals. Log IL-7 increased from week 12 to week 24. DISCUSSION: Initially elevated IL-6 serum concentrations appear to 'normalize' during the first 3-months of specialised treatment for AN and this co-occurs with improvements in ED symptoms. Therefore, IL-6 has the potential to be a state biomarker for AN.

The effect of repetitive transcranial magnetic stimulation on food choice-related self-control in patients with severe, enduring anorexia nervosa.

OBJECTIVE: Individuals with anorexia nervosa (AN) pursue low-fat, low-calorie diets even when in a state of emaciation. These maladaptive food choices may involve fronto-limbic circuitry associated with cognitive control, habit, and reward. We assessed whether high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex (DLPFC) influenced food-related choice behavior in patients with severe, enduring (SE)-AN. METHOD: Thirty-four females with SE-AN completed a Food Choice Task before and after 20 sessions of real or sham rTMS treatment and at a 4-month follow-up. During the task, participants rated high- and low-fat food items for healthiness and tastiness and then made a series of choices between a neutral-rated food and high- and low-fat foods. Outcomes included the proportion of high-fat and self-controlled choices made. A comparison group of 30 healthy women completed the task at baseline only. RESULTS: Baseline data were consistent with previous findings: relative to healthy controls, SE-AN participants showed a preference for low-fat foods and exercised self-control on a greater proportion of trials. There was no significant effect of rTMS treatment nor time on food choices related to fat content. However, among SE-AN participants who received real rTMS, there was a decrease in self-controlled food choices at post-treatment, relative to baseline. Specifically, there was an increase in the selection of tasty-unhealthy foods. DISCUSSION: In SE-AN, rTMS may promote more flexibility in relation to food choice. This may result from neuroplastic changes in the DLPFC and/or in associated brain areas.

Repetitive transcranial magnetic stimulation treatment in severe, enduring anorexia nervosa: An open longer-term follow-up.

OBJECTIVE: This study assessed longer-term outcomes from a randomised controlled feasibility trial of 20 sessions of real versus sham high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex in adults with severe, enduring anorexia nervosa (SE-AN). METHODS: Thirty participants who completed the original study protocol were invited to take part in an open follow-up (18-months post-randomisation), assessing body mass index (BMI), eating disorder (ED) symptoms and other psychopathology. RESULTS: Twenty-four participants (12 each originally allocated to real/sham) completed the 18-month follow-up. Ten of 12 participants who originally received sham treatment had real rTMS at some stage during the follow-up. A medium between-group effect size was seen for BMI change from baseline to 18-months, favouring those originally allocated to real rTMS. In this group at 18-months, five participants were weight recovered (BMI ≥18.5 kg/m2 ), compared with one participant in the original sham group. Both groups showed further improvement in ED symptoms during the follow-up. Effects on mood were largely maintained at follow-up, with catch-up effects in the original sham group. CONCLUSIONS: Findings suggest that rTMS treatment effects on mood are durable and that BMI and ED symptom improvements need time to emerge. Large-scale trials are needed.

Brain white matter microstructure in obese women with binge eating disorder.

OBJECTIVE: Research on potential brain circuit abnormalities in binge eating disorder (BED) is limited. Here, we assess white matter (WM) microstructure in obese women with BED. METHOD: Diffusion tensor imaging data were acquired, and tract-based spatial statistics used to examine WM in women with BED who were obese (n = 17) compared to normal-weight (NWC) (n = 17) and to women who were obese (OBC) (n = 13). Body mass index (BMI) was a covariate in the analyses. RESULTS: The BED group (vs. NWC) had greater axial diffusion (AD) in the forceps minor, anterior thalamic radiation, superior and inferior longitudinal fasciculus, that is, in pathways connecting fronto-limbic regions. Microstructures differences in AD between the BED and OBC groups were seen in fronto-limbic pathways extending to temporoparietal pathways. The BED (vs. OBC) group had greater fractional anisotropy in the forceps minor and greater AD in the superior longitudinal fasciculus, cingulate gyrus, and corpus callosum, consistent with fronto-tempoparietal pathways. CONCLUSION: Women with BED show WM alterations in AD in fronto-limbic and parietal pathways that are important in decision-making processes. As BMI was a covariate in the analyses, alterations in BED may be part of the pathology, but whether they are a cause or effect of illness is unclear.

Test-retest reliability of attention bias for food: Robust eye-tracking and reaction time indices.

This study assessed internal reliability and test-retest reliability of attention bias scores for food derived from the dot probe task. A visual dot probe task with food and non-food pictures (presented for 3000 ms) was administered to 53 healthy women on two occasions. Attention bias scores for food were calculated based on manual response latencies (reaction time bias) and concurrent assessment of eye-movements (direction bias and dwell-time bias). Subjective hunger and blood glucose levels were measured on both testing occasions. Dietary restraint and eating disorder symptoms were assessed during the second session. Results showed that direction bias had poor internal and test-retest reliability. Dwell time bias had excellent internal and acceptable test-retest reliability. Reaction time bias had acceptable internal and good test-retest reliability. Exploratory correlational analyses found that hunger, blood glucose, dietary restraint and eating disorder symptoms were not consistently significantly correlated with indices of attention bias for food. Overall, these findings contradict previous studies that reported low reliability of attention bias indices derived from the visual dot probe task. The implications are that a longer stimulus presentation time (i.e. ≥ 3000 ms), the use of eye-tracking and the use of appetizing stimuli can yield reliable attention bias scores for food. However, the interpretation of dot-probe scores of attention bias for food based on a dot probe task with 3000 ms presentation time and the score's relationship to theoretically relevant constructs such as hunger, eating restraint and eating disorder symptoms, require further clarification.

Why some obese people become depressed whilst others do not: exploring links between cognitive reactivity, depression and obesity.

Obesity and depression are two major public health concerns, particularly when they co-occur. To date, mechanisms underlying this association have not been established and it is unclear why some obese people become depressed whilst others do not. However, considering the strong association between depression and cognitive reactivity (CR), the present study explores possible associations between obesity, depression and CR in light of the scarce and conflicting nature of past literature. 254 participants were included for measures of depression, CR and obesity. Multivariate analyses of covariance examined the effects of depression and obesity as well as interaction effects of depression x obesity controlling for age and gender. Directions of effects were analysed by means of regression analyses and group contrasts. Linear analyses revealed (1) a significant effect of obesity on the rumination (RUM) and control/perfectionism subscales of CR, (2) a significant effect of depression on CR and all of its subscales, and (3) a significant interaction effect between obesity x depression on RUM. Results may support the 'Jolly Fat Hypothesis' and the existence of a psychologically protected subgroup of obese patients characterised by a lower ruminative thinking style and fewer depressive symptoms. Thus, incorporating anti-rumination therapy into treatment for obese individuals may be beneficial to prevent the development of comorbid depression.

A case series to investigate food-related fear learning and extinction using in vivo food exposure in anorexia nervosa: A clinical application of the inhibitory learning framework.

OBJECTIVE: Anorexia nervosa is characterized by severe malnutrition. This study tested the hypothesis that fear of food is a learned behaviour and evaluated the feasibility and effectiveness of gradual exposure to food to improve eating behaviour in people with anorexia nervosa. METHODS: Eighteen women were recruited and completed baseline self-reports. They were interviewed regarding early experiences of eating and the development of food-related anxiety. Participants received eight sessions of in vivo food exposure. RESULTS: Findings indicated that fear of food is a learned behaviour, associated with catastrophic thoughts around the consequences of eating and safety behaviours. Patients consumed at least half of the food item selected in all but one session. Body mass index increased, and food restriction, eating concern, eating disorder-related preoccupations, and overall anxiety reduced (medium/large ES). CONCLUSION: Findings corroborate an anxiety-based model of anorexia nervosa and support the relevance of targeting food-related fears using exposure-based protocols.

Identifying disordered eating behaviours in adolescents: how do parent and adolescent reports differ by sex and age?

This study investigated the prevalence of disordered eating cognitions and behaviours across mid-adolescence in a large European sample, and explored the extent to which prevalence ratings were affected by informant (parent/adolescent), or the sex or age of the adolescent. The Development and Well-Being Assessment was completed by parent-adolescent dyads at age 14 (n = 2225) and again at age 16 (n = 1607) to explore the prevalence of 7 eating disorder symptoms (binge eating, purging, fear of weight gain, distress over shape/weight, avoidance of fattening foods, food restriction, and exercise for weight loss). Informant agreement was assessed using kappa coefficients. Generalised estimating equations were performed to explore the impact of age, sex and informant on symptom prevalence. Slight to fair agreement was observed between parent and adolescent reports (kappa estimates between 0.045 and 0.318); however, this was largely driven by agreement on the absence of behaviours. Disordered eating behaviours were more consistently endorsed amongst girls compared to boys (odds ratios: 2.96-5.90) and by adolescents compared to their parents (odds ratios: 2.71-9.05). Our data are consistent with previous findings in epidemiological studies. The findings suggest that sex-related differences in the prevalence of disordered eating behaviour are established by mid-adolescence. The greater prevalence rates obtained from adolescent compared to parent reports may be due to the secretive nature of the behaviours and/or lack of awareness by parents. If adolescent reports are overlooked, the disordered behaviour may have a greater opportunity to become more entrenched.

Temporal Discounting and the Tendency to Delay Gratification across the Eating Disorder Spectrum.

Bulimia nervosa (BN) and binge eating disorder (BED) have been associated with poorer reward-related inhibitory control, reflected by a reduced tendency to delay gratification. The opposite has been reported in anorexia nervosa (AN), but differences have not been directly compared across eating disorders (EDs). This study investigated self-reported (Delaying Gratification Inventory) and task-based (temporal discounting) inhibitory control in 66 women with an ED and 28 healthy controls (HCs). Poorer task-based inhibitory control was observed in the BN compared with the AN group and poorer self-reported inhibitory control in the BN and in the BED groups compared with the AN and the HC groups, suggesting that reward-related inhibitory control varies across EDs. Symptom severity correlated with poorer self-reported (but not task-based) inhibitory control across the EDs. These data provide some support for transdiagnostic mechanisms and highlight the importance of addressing perceived loss of control in the treatment of EDs. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Increased temporal discounting in bulimia nervosa.

OBJECTIVE: There is evidence that people with eating disorders display altered intertemporal choice behavior (the degree of preference for immediate rewards over delayed rewards). Compared to healthy controls (HC), individuals with anorexia nervosa and binge-eating disorder show decreased and increased rates of temporal discounting (TD; the devaluation of delayed rewards), respectively. This is the first study to investigate TD in people with bulimia nervosa (BN). METHOD: Thirty-nine individuals with BN (2 men) and 53 HC (9 men) completed a hypothetical monetary TD task. Over 80 binary choices, participants chose whether they would prefer to receive a smaller amount of money available immediately or a larger amount available in 3 months. Self-reported ability to delay gratification (the behavioral opposite of TD) was also measured. RESULTS: Individuals with BN showed greater TD (i.e., a preference for smaller-sooner rewards) and a decreased self-reported capacity to delay gratification relative to HC. Experimental groups did not differ in age, gender ratio, or BMI. DISCUSSION: Increased rates of TD may contribute to some of the core symptoms of BN that appear to involve making choices between immediate and delayed rewards (i.e., binge-eating and compensatory behaviors). Altered intertemporal choice behavior could therefore be a relevant target for intervention in this patient group. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1077-1081).

Repetitive Transcranial Magnetic Stimulation (rTMS) Treatment in Enduring Anorexia Nervosa: A Case Series.

OBJECTIVES: This case series examined the therapeutic potential of repetitive transcranial magnetic stimulation in five women with enduring anorexia nervosa. METHODS: Participants received ~20 sessions of neuronavigated high-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex. Body mass index, eating disorder (ED) symptoms and mood were assessed pre-treatment and post-treatment, at 6-month and 12-month follow-up (FU). Qualitative feedback regarding the intervention was obtained from participants and carers. RESULTS: From pre-treatment to post-treatment, ED and affective symptoms improved significantly, and body mass index remained stable. Further improvements in ED symptoms/mood were seen at 6-month FU with 3/5 and 2/5 participants deemed 'recovered' on the Eating Disorders Examination Questionnaire and Depression, Anxiety and Stress Scale, respectively. However, most participants had lost some weight, and therapeutic effects on psychopathology had waned by 12-month FU. Qualitative feedback regarding the intervention was encouraging. DISCUSSION: Repetitive transcranial magnetic stimulation was well tolerated, and preliminary evidence is provided for its therapeutic potential in anorexia nervosa.

Physical activity and the drive to exercise in anorexia nervosa.

OBJECTIVES: To investigate physical activity (PA) and drive for exercise in anorexia nervosa (AN) in relation to eating disorder (ED) pathology and anxiety. METHOD: Female participants were recruited into four groups: AN outpatients (n = 37), AN inpatients (n = 18), an anxiety group (n = 34), and healthy controls (HCs; n = 30). PA was measured by actigraphy and self-report together with drive/reasons for exercise, ED pathology, anxiety, depression, stress, BMI, and body composition. RESULTS: ED psychopathology, general psychopathology, and physiological measures were consistent with diagnosis. All groups showed a wide range in activity, especially on self-report. No significant group differences were observed in objective PA levels, yet AN groups reported 57-92% higher total activity than HCs. Outpatients reported more walking and moderate exercise than HCs, and inpatients reported more walking but less moderate and vigorous activity than all other groups. AN groups had significantly higher drive to exercise and valued "improving tone" as important and health and enjoyment as less important reasons to exercise. DISCUSSION: Self-perceived activity rather than objective data may partly explain the increased activity reported in AN. Drive to exercise in AN appears to be more related to ED pathology than to anxiety.

Increases in weight during chronic stress are partially associated with a switch in food choice towards increased carbohydrate and saturated fat intake.

We examined if stress associated changes in weight and dietary restraint are associated with changes in the composition of foods consumed. Participants were 38 healthy women on a taught postgraduate university course. Data were obtained at the beginning of the semester and 15 weeks later just prior to a written course exam (the stressor). By using a within subject design, we measured the composition of food consumed, body mass index (BMI), levels of dietary restraint and salivary cortisol. In the larger study from which these data were obtained, it was shown that the effect of increased cortisol secretion on weight gain was mediated by a reduction in dietary restraint. The present data show that increased cortisol secretion, reduced dietary restraint and increased caloric intake, account for 73% of the variance in change in BMI. Further regression analysis indicated that the change in dietary restraint mediated the effect of change in cortisol on change in BMI. Final analysis revealed that the effect of these changes in dietary restraint on weight are partially mediated by increased caloric intake from carbohydrate and saturated fat, that is, a change in dietary composition partially accounts for the link between increased cortisol secretion through heightened hypothalamic-pituitary-adrenal activity resulting in weight gain. These data are consistent with a 'comfort food hypothesis', as they suggest that chronic stress can promote reward associated behaviour through reduced dietary restraint and consumption of food containing more carbohydrate and saturated fat.