Implicit affective associations predict snack choice for those with low, but not high levels of eating disorder symptomatology

Implicit bias to food and body cues in eating disorders: a systematic review

BACKGROUND

Rigid, restrictive eating patterns, fear of gaining weight, body image concerns, but also binge eating episodes with loss of control leading to overweight, at times followed by compensatory measures to control weight, are typical symptoms in eating disorders (EDs). The regulation of food intake in EDs may underlie explicit processes that require cognitive insight and conscious control or be steered by implicit mechanisms that are mostly automatic, rapid, and associated with affective-rather than cognitive-processing. While introspection is not capable of assessing implicit responses, so-called indirect experimental tasks can assess implicit responses underlying a specific behavior by-passing the participant's consciousness. Here, we aimed to present the current evidence regarding studies on implicit biases to food and body cues in patients with EDs.

METHODS

We performed a systematic review (PRISMA guidelines). We included controlled studies performed in clinical ED cohorts (vs. healthy control subjects or another control condition, e.g., restrictive vs. binge/purge AN) and using at least one indirect assessment method of interest.

RESULTS

Out of 115 screened publications, we identified 29 studies fulfilling the eligibility criteria, and present a synthesis of the essential findings and future directions.

CONCLUSION

In this emerging field of research, the present work provides cornerstones of evidence highlighting aspects of implicit regulation in eating disorders. Applying both direct (e.g., self-reports) and indirect measures for the assessment of both explicit and implicit responses is necessary for a comprehensive investigation of the interplay between these different regulatory mechanisms and eating behavior. Targeted training of implicit reactions is already in use and represents a useful future tool as an add-on to standard psychotherapeutic treatments in the battle against eating disorders.

EVIDENCE LEVEL

1 (systematic review).

Relations between implicit attitudes towards eating disorder stimuli and disordered eating symptoms among at-risk college women

This study examined implicit attitudes towards different eating disorder (ED) relevant stimuli- emaciation, hard-exercise, the self, and eating related stimuli-and their relationship with explicit ED symptoms in two symptomatic samples of college-aged women. Study 1 found that positive implicit attitudes towards eating and self-relevant images were associated with greater state body image satisfaction and self-esteem and with less ED-related intentions. Study 2 found that positive implicit attitudes towards eating and self-relevant images were associated with less trait global ED psychopathology and distress and greater self-esteem. Overall, positive implicit evaluations of eating and self-related stimuli were negatively associated with ED symptoms and related psychopathology and positively related to self-esteem. However, implicit attitudes towards emaciation and hard exercise were not associated with explicit ED symptoms in either sample. These findings suggest that implicit attitudes towards eating and self-related stimuli, in particular, may be viable targets for reconditioning in novel treatment paradigms such as therapeutic evaluative conditioning interventions.

A Systematic Review Of Implicit Attitudes And Their Neural Correlates In Eating Behaviour

An increasing number of studies suggests that implicit attitudes toward food and body shape predict eating behaviour and characterize patients with eating disorders (EDs). However, literature has not been previously analysed, thus differences between patients with EDs and healthy controls and the level of automaticity of the processes involved in implicit attitudes are still matters of debate. The present systematic review aimed to synthetize current evidence from papers investigating implicit attitudes towards food and body in healthy and EDs populations. PubMed, EMBASE (Ovid), PsycINFO, Web of Science and Scopus were systematically screened and 183 studies using different indirect paradigms were included in the qualitative analysis. The majority of studies reported negative attitudes towards overweight/obese body images in healthy and EDs samples and weight bias as a diffuse stereotypical evaluation. Implicit food attitudes are consistently reported as valid predictors of eating behaviour. Few studies on the neurobiological correlates showed neurostimulation effects on implicit attitudes, but the automaticity at brain level of implicit evaluations remains an open area of research. In conclusion, implicit attitudes are relevant measures of eating behaviour in healthy and clinical settings, although evidence about their neural correlates is limited.

Assessing the Relationship Between Implicit and Explicit Evaluations of Fruit and Vegetable Consumption by Cancer Survivors

BACKGROUND

Currently, little is known about the implicit evaluations that cancer survivors have for health behaviors, such as eating fruits and vegetables. Understanding both the implicit and explicit evaluations of fruit and vegetable consumption among cancer survivors may aid future interventions for changing motivations and intentions in this higher risk population.

METHODS

A cross-sectional study at a university cancer center assessed explicit and implicit evaluations of fruit and vegetable consumption among 122 cancer survivors. The explicit evaluations regarding fruit and vegetable consumption were self-report data. To obtain implicit evaluations, participants completed an implicit evaluation task, the Affect Misattribution Paradigm. Moderating variables of time since first cancer treatment and if participants had a prior cancer occurrence were also self-reported.

RESULTS

Simple correlations found no significant association between the implicit and explicit evaluations of fruit and vegetable consumption. Moderation regression analyses showed that the implicit and explicit evaluations became negatively associated as time since first treatment increased and when participants had a prior cancer occurrence.

CONCLUSION

The results support the view that implicit and explicit measures of fruit and vegetable consumption diverge for cancer survivors, consistent to implicit and explicit evaluations in other domains and samples. Further, the association between these evaluations differed depending on time since first treatment and if they have been treated for a prior cancer occurrence. By knowing more about implicit and explicit positive evaluations, and their moderators, it may be possible for interventionists to alter cancer survivors' motivation and intention to eat fruits and vegetables.

Implicit attitudes toward eating stimuli differentiate eating disorder and non-eating disorder groups and predict eating disorder behaviors

OBJECTIVE

The current study tested whether people with and without eating disorders (EDs) varied in their implicit attitudes toward ED-relevant stimuli. Additionally, the study tested whether implicit evaluations of ED-relevant stimuli predicted ED symptoms and behaviors over a 4-week interval.

METHOD

Participants were people without EDs (N = 85) and people seeking treatment for EDs (N = 92). All participants completed self-report questionnaires and a version of the affect misattribution procedure (AMP) at baseline. The AMP indexed implicit evaluations of average body stimuli, eating stimuli, and ED-symptom stimuli. Participants with EDs completed weekly follow-up measures of ED symptoms and behaviors for 4 weeks.

RESULTS

Contrary to predictions, the anorexia nervosa (AN) group did not differ from the no ED group on implicit attitudes toward ED-symptom stimuli, and the bulimia nervosa (BN) group had less positive implicit attitudes toward ED-symptom stimuli relative to the no ED group. In line with predictions, people with AN and BN had more negative implicit attitudes toward average body and eating stimuli relative to the no ED group. In addition, among the ED group more negative implicit attitudes toward eating stimuli predicted ED symptoms and behaviors 4 weeks later, over and above baseline ED symptoms and behaviors.

DISCUSSION

Taken together, implicit evaluations of eating stimuli differentiated people with AN and BN from people without EDs and longitudinally predicted ED symptoms and behaviors. Interventions that increase implicit liking of eating-related stimuli may reduce ED behaviors.