Understanding the link between body image and binge eating: a model comparison approach

Purpose
The present study tests several competing, explanatory models—dual pathways, escape from awareness, and objectification theory—for the established link between body dissatisfaction and binge eating.

Methods
408 women aged between 18 and 40 years completed a survey designed to assess contributions of proposed mediators (dietary restraint and negative affect from the dual pathway model, self-distraction from the escape from awareness model, and interoceptive deficits from objectification theory) for the body dissatisfaction–binge eating relationship.

Results
Although mediation analyses supported the dual pathway model and objectification theory when tested separately, the dual pathway model most strongly predicted the body dissatisfaction–binge eating relationship. Both model-implied mediators (dietary restraint and negative affect) made significant unique contributions, accounting for roughly one-quarter of the shared variance between body dissatisfaction and binge eating when tested separately from other mediators. Improvements in variance explained were negligible once other proposed mediators were included in a test of models combined.

Conclusions
Collectively, these findings suggest the superiority of the dual pathway model over objectification theory and the escape model, but the remaining unaccounted for covariance suggests need to consider alternative mechanisms that may also account for the relationship between body dissatisfaction and binge eating.

Understanding the link between body dissatisfaction and binge eating: a model comparison approach

 This thesis explored the association between body dissatisfaction and binge eating by comparing three competing theoretical frameworks. Study I utilised a cross-sectional design and collectively these findings suggest the superiority of the dual pathway model (dietary restraint and negative affect) over the objectification theory and the escape model. The purpose of Study II was then to extend on the findings from Study I by further examining in real-time the model/theory that most strongly explained the body dissatisfaction-binge eating relationship. Participants were prompted at random intervals seven times daily across the course of a week to self-report their state body dissatisfaction, current mood experiences, and eating practices. Results revealed that negative mood, but not dietary restraint, significantly mediated the state body dissatisfaction-binge eating relationship. These results highlight that the dual pathway model is robust, but raise the possibility that the dietary restraint path in the model is not well operationalized. In light of the non-significant mediating effect of dietary restraint, this led the researcher to identify various modeling alternatives to further understand the mediating influences of the pathways of negative affect and dietary restraint.

Integrating environmental sustainability considerations into food and nutrition policies : insights from Australia's national food plan

The environmental sustainability (ES) of food systems is a critical challenge for policy makers. This is a highly contested policy area with differing views among stakeholders. The aim of the study was to develop a better understanding of how ES considerations are addressed in Australian food and nutrition policies and the way that consultation processes affect final policy outcomes. A mixed-methods study design combined a detailed chronology of key policy developments (2009-2015), a content analysis of written submissions obtained during the NFP's consultation period (2011-2013) and a frame analysis of the sustainability perspectives - efficiency, demand restraint, and system transformation - in the NFP's Issues, Green, and White Papers. There were 555 written submissions responding to two consultation papers. Stakeholders represented all sectors of Australia's food system including government, non-government organizations, the food supply chain, research and academic institutions, and members of the general public. Around 74% of submissions referred to ES considerations and ~65% supported their inclusion into the final policy. Efficiency frames were most dominant; emphasizing a production-oriented approach that regards the environment as a natural resource base for food production but overlooks consumption and equity concerns. Despite strong support for the inclusion of ES considerations in the NFP, the influence of Australia's socio-political context, powerful, industry-dominated stakeholders, and a reliance on traditional production-oriented perspectives delivered a business-as-usual approach to food policy making. It has since been replaced by an agricultural strategy that provides only cursory attention to ES. Our findings indicate that Australia's political environment is not sufficiently mature for ES considerations to be integrated into food and nutrition policies. We propose reforms to the current consultation process in Australia to better support this integration by promoting greater transparency and participation in the development of food and nutrition policy making.

Doing the counter-regulation shuffle: the importance of flexibility and hunger for predicting food consumption following a preload

Objectives
This study utilised the preload paradigm to evaluate whether trait-like dieting attitudes and behaviours (dietary restraint and flexibility in dieting rules) and context-specific factors (negative mood and hunger) predict food consumption among male and female participants.
Methods
Following a high calorie preload, 79 participants aged 18–40 completed a deceptive taste test in which they were encouraged to eat as much of the taste test foods as desired, and this ad libitum intake was measured.
Results
Although each predictor (except negative mood) predicted consumption when tested individually, regression analyses revealed that dieting flexibility and current hunger were the strongest unique predictors of intake. Mood failed to directly predict food consumption, nor did it moderate the relationship between restraint and food intake.ConclusionCollectively, findings suggest that emphasis on dietary restraint in preload studies may be misplaced, as other proximal and stable factors may better predict food consumption.

Applicability of the dual pathway model in normal and overweight binge eaters

Binge eating is a significant problem in both eating disordered and community populations alike. Extensive support exists for the dual pathway model of binge eating in both adolescent and adult clinical and nonclinical populations. However, the restrained eating pathway to binge eating in particular has failed to be confirmed in some studies. In particular, the dual pathway model may not be applicable to overweight binge eaters. The current study examined the applicability of the dual pathway model in a sample of healthy and overweight binge eaters. A total of 260 (115 healthy weight; 145 overweight or obese) adult binge eaters completed an online survey. Mediation analyses indicated support for both the dietary restraint and negative affect pathways in the healthy weight sample but only the latter pathway was supported in the overweight sample. Therefore, the full dual pathway model may only be applicable to healthy weight binge eaters.

Learning how to engage students online in hard times

In a context of financial restraint and enterprising university managers, teacher-researchers have reason to be sceptical about the trend towards online teaching and away from learning for its own sake. This article departs from both economic and technological determinism and turns instead to ideas about technology embedded in social and political institutions. Activity theory offers a useful means of analysing such embeddedness. Its Marxian assumptions about human nature specify a non-deterministic approach to technology. Its dynamic model of the subjects, tools, and objects of activity within a context of rules, a community, and a division of labour helps to specify aspects of the authors process of learning how to use electronic conferencing effectively. A full deployment of activity theory would also analyse the activity of students. Here the evidence comes mainly from the activity of researcher-teachers engaging greater activity among students. The numbers of students involved precludes reliable quantitative analysis but qualitative evidence from students does support conclusions about researcher-teachers learning how to make best use of electronic conferencing.

General anaesthesia or conscious sedation for painful procedures in childhood cancer: the family's perspective

Background: Until recently, midazolam sedation was routinely used in our institution for bone marrow aspirates and lumbar punctures in children with cancer. It has been perceived by many doctors and nurses as being well tolerated by children and their families.

Aim: To compare the efficacy of inhalational general anaesthesia and midazolam sedation for these procedures.

Methods: A total of 96 children with neoplastic disorders, who received either inhalational general anaesthesia with sevoflurane, nitrous oxide, and oxygen (GA) or sedation with oral or nasal midazolam (SED) as part of their routine preparation for procedures were studied. The experiences of these childen were examined during their current procedure and during their first ever procedure. Main outcome measures were the degree of physical restraint used on the child, and the levels of distress and pain experienced by the child during the current procedure and during the first procedure. The family‘s preference for future procedures was also determined.

Results: During 102 procedures under GA, restraint was needed on four occasions (4%) when the anaesthetic mask was first applied, minimal pain was reported, and children were reported as distressed about 25% of the time. During 80 SED procedures, restraint was required in 94%, firm restraint was required in 66%, the child could not be restrained in 14%, median pain score was 6 (scale 0 (no pain) to 6 (maximum pain)), and 90% of the parents reported distress in their child. Ninety per cent of families wanted GA for future procedures. Many families reported dissatisfaction with the sedation regime and raised concerns about the restraint used on their child.

Conclusions: This general anaesthetic regime minimised the need for restraint and was associated with low levels of pain and distress. The sedation regime, by contrast, was much less effective. There was a significant disparity between the perceptions of health professionals and those of families with respect to how children coped with painful procedures.

Iniatives to reduce the use of seclusion and restraints on people with developmental disabilities: a systematic review and quantitative synthesis

Contrary to the expectations articulated in public policy, restrictive interventions are commonly used in support services for people with developmental disabilities. This systematic review and quantitative synthesis was undertaken to investigate whether the use of seclusion and restraints on people with developmental disabilities can be reduced. Searches of the Academic Search Complete, CINAHL, MEDLINE, and PsycINFO electronic databases returned 7226 records, of which 11 met the inclusion criteria for this review. A further 3 papers were obtained through scanning the reference lists of those articles included from the initial literature search. All 14 studies were single-subject designs focusing on initiatives to reduce physical or mechanical restraint. Between the baseline and intervention phases, there were mean reductions in the frequency and duration of restraint use of 79% (SD = 21%, n = 13 subjects from 7 studies) and 45% (SD = 58%, n = 10 subjects from 6 studies), respectively. For studies in which restraint use to manage agitation and aggression was targeted, there was a 79% (SD = 21%, n = 13 subjects from 7 studies) decrease in the frequency and a 28% (SD = 67%, n = 6 subjects from 3 studies) reduction in the duration of restraint. With respect to studies in which restraint use to prevent self-harm was targeted, there was a 71% (SD = 34%, n = 4 subjects from 3 studies) reduction in restraint use. Effect sizes were calculable, using non-overlap approaches, for 9 of the 14 studies. The magnitudes of the effect sizes suggest that, on average, the interventions were effective in reducing the use of restraints. The effects generated in studies where restraint use for self-harm was targeted were typically more pronounced than those in which restraint use for agitation and aggression was addressed. There were broad variations, however, in the percentage reductions in restraint use and in the magnitudes of the effect sizes. Although the findings of this review are encouraging, more research is needed, in which greater attention must be paid to rigorous research design, application, and analysis.

Individual and organisational factors associated with the use of seclusion in disability services

Background: Seclusion is a restrictive intervention that results in some form of containment and social isolation of a person from others. Little is known about the relationships between individual and organisation factors and the use of seclusion in disability services. Method: The reported use of seclusion in disability services in Victoria, Australia, was examined over a 3-year period, with a focus on the characteristics of those who were secluded (n = 146) and the characteristics of organisations that reported seclusion compared to others who were reported to be restrained but not secluded (n = 2,482). Results: Results from a logistic regression showed that the individual factors of age, the presence of autism and/or a psychiatric disorder put people at risk of being secluded. In terms of organisational factors, receiving accommodation services in institutions or in the community and the location of the organisation were risk factors. Conclusions: The findings are consistent with previous research but add to this literature by showing that certain organisational characteristics are also risk factors for seclusion. Understanding these factors is important in order to help disability support staff find other more ethical and appropriate alternatives to seclusion.

Responses of the hypothalamopituitary adrenal axis and the sympathoadrenal system to isolation/restraint stress in sheep of different adiposity

There is evidence that levels of adipose tissue can influence responses of the hypothalamopituitary-adrenal (HPA) axis to stress in humans and rats but this has not been explored in sheep. Also, little is known about the sympathoadrenal responses to stress in individuals with relatively different levels of adipose tissue. We tested the hypothesis that the stress-induced activation of the HPA axis and sympathoadrenal system is lower in ovariectomized ewes with low levels of body fat (lean) than ovariectomized ewes with high levels of body fat (fat). Ewes underwent dietary manipulation for 3 months to yield a group of lean ewes (n = 7) with a mean (±SEM) live weight of 39.1 ± 0.9 kg and body fat of 8.9 ± 0.6% and fat ewes (n = 7) with a mean (±SEM) live weight of 69.0 ± 1.8 kg and body fat of 31.7 ± 3.4%. Fat ewes also had higher circulating concentrations of leptin than lean ewes. Blood samples were collected every 15 min over 8 h when no stress was imposed (control day) and on a separate day when 4 h of isolation/restraint was imposed after 4 h of pretreatment sampling (stress day). Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, epinephrine and norepinephrine did not change significantly over the control day and did not differ between lean and fat ewes. Stress did not affect plasma leptin levels. All stress hormones increased significantly during isolation/restraint stress. The ACTH, cortisol and epinephrine responses were greater in fat ewes than lean ewes but norepinephrine responses were similar. Our results suggest that relative levels of adipose tissue influence the stress-induced activity of the hypothalamopituitary-adrenal axis and some aspects of the sympathoadrenal system with fat animals having higher responses than lean animals.

Isolation and restraint stress results in differential activation of corticontrophin-releasing hormone and arginine vasopressin neurones in sheep

This study investigated sex differences in the stress-induced activation of neurons containing corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP) and enkephalin in the paraventricular nucleus (PVN) of gonadectomized male and female sheep. Groups (n=3) of both sexes were either subjected to 90 min isolation and restraint stress (stress group) or were not stressed. Blood samples were taken every 10 min for 90 min prior to and after stress to monitor cortisol levels in plasma. Brains were harvested after 90 min of stress. Stress caused elevation of plasma cortisol levels to a similar extent in both sexes. Double-labeling immunohistochemistry for Fos and either CRH, AVP or enkephalin was undertaken to quantify the numbers of neurons staining for CRH, AVP and enkephalin that also immunostained for Fos. Stress increased Fos immunostaining in all cell types. There was a greater proportion of CRH than AVP neurons activated in stressed animals. There were no sex differences in the activation of CRH and AVP neurons although females had a greater proportion of enkephalin cells staining for Fos than males in both control and stressed animals. There were no differences between control and stressed animals in the proportion of cells co-staining for CRH and AVP. We conclude that isolation and restraint stress activates neurons producing CRH, AVP and enkephalin in sheep and that CRH may play a greater role than AVP in regulating adrenocorticotrophic hormone secretion in response to this stressor in sheep. Finally, isolation and restraint stress does not influence co-localization of CRH and AVP in sheep.

Activation of the hypothalamo-pituitary-adrenal axis by isolation and restraint stress during lactation in ewes : effect of the presence of the lamb and suckling

We investigated the effect of the presence and absence of lambs and suckling by lambs to attenuate activation of the hypothalamo-pituitary-adrenal (HPA) axis to isolation and restraint stress in lactating sheep. In experiment 1, blood samples were collected every 10 min from nonlactating (n = 5) and lactating (n = 5) ewes for 4 h before and during stress. In experiment 2, ewes (n = 6) were allocated to 1) nonlactating, 2) lactating with lambs absent, 3) lactating with lambs present but unable to suckle, and 4) lactating with lambs present and able to suckle. Blood samples were collected over 8 h with no stress (control day) and for 4 h before and 4 h during stress (stress day). In experiment 1, the mean (±SEM) cortisol concentrations increased significantly (P < 0.05) in nonlactating ewes during stress but did not change in lactating ewes. In experiment 2, cortisol did not vary on the control day or pretreatment of the stress day but increased (P < 0.05) during stress in all groups except lactating ewes with lambs present and able to suckle. The greatest cortisol response occurred in nonlactating ewes followed by lactating ewes with lambs absent and lactating ewes with lambs present but unable to suckle. During stress, the ACTH concentrations increased (P < 0.05) in nonlactating ewes and lactating ewes with lambs absent but not in lactating ewes with lambs present. We conclude that the activity of the HPA axis during isolation and restraint is reduced in lactating ewes and that the presence of lambs increases this level of attenuation.

Seasonal differences in the effect of isolation and restraint stress on the luteinizing hormone response to gonadotropin-releasing hormone in hypothalamopituitary disconnected, gonadectomized rams and ewes

Stress responses are thought to act within the hypothalamopituitary unit to impair the reproductive system, and the sites of action may differ between sexes. The effect of isolation and restraint stress on pituitary responsiveness to GnRH in sheep was investigated, with emphasis on possible sex differences. Experiments were conducted during the breeding season and the nonbreeding season. In both experiments, 125 ng of GnRH was injected i.v. every 2 h into hypothalamopituitary disconnected, gonadectomized rams and ewes on 3 experimental days, with each day divided into two periods. During the second period on Day 2, isolation and restraint stress was imposed for 5.5 h. Plasma concentrations of LH and cortisol were measured in samples of blood collected from the jugular vein. In the second experiment (nonbreeding season), plasma concentrations of epinephrine, norepinephrine, 3,4-dihydroxyphenylalanine, and 3,4-dihydroxyphenylglycol were also measured. In both experiments, there was no effect of isolation and restraint stress on plasma concentrations of cortisol in either sex. During the breeding season, there was no effect of isolation and restraint stress on plasma concentrations of LH in either sex. During the nonbreeding season, the amplitude of the first LH pulse after the commencement of stress was significantly reduced (P < 0.05) in rams and ewes. In the second experiment, during stress there was a significant increase (P < 0.05) in plasma concentrations of epinephrine in rams and ewes and significantly higher (P < 0.05) basal concentrations of norepinephrine in ewes than in rams. These results suggest that in sheep stress reduces responsiveness of the pituitary gland to exogenous GnRH during the nonbreeding season but not during the breeding season, possibly because of mediators of the stress response other than those of the hypothalamus-pituitary-adrenal gland axis.