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

Testing Go/No-Go training effects on implicit evaluations of unhealthy and healthy snack foods

OBJECTIVE

Despite intending to eat healthy foods, people often yield to temptation. In environments rife with unhealthy food options, a positive implicit evaluation of unhealthy foods may inadvertently influence unhealthy choices. This study investigates if and under which conditions implicit evaluations of unhealthy and healthy foods can be influenced by a computer-based Go/No-Go (GNG) training.

DESIGN

Undergraduate student participants (N = 161 participants; 117 females, 44 males; Mage = 19 years, SD = 2 years) completed a GNG training with two healthy (grape and nut) and two unhealthy (potato chip and cookie) stimuli. Participants were either instructed to inhibit their responses to the potato chip (No-Go Chips/Go Grape) or to a grape (No-Go Grape/Go Chips).

MAIN OUTCOME MEASURE

Implicit evaluations of chips and grapes were assessed using the Extrinsic Affective Simon Task.

RESULTS

This GNG training impacted implicit evaluations of chips, but not grapes. GNG training effects were stronger for participants with lower sensitivity for behavioural inhibition measured with the Behavioural Inhibition System scale.

CONCLUSION

GNG training might help people change implicit food evaluations. More research is needed to understand how individual and training characteristics affect outcomes with the goal of tailoring and optimising the GNG training to produce the strongest effect.

A pilot randomized trial of the body advocacy movement: a novel, dissonance-based intervention designed to target fear of weight gain and anti-fat bias in young adults

The Body Advocacy Movement (BAM) is a novel, cognitive-dissonance-based intervention designed to target fatphobia and anti-fat bias as mechanisms to drive reductions in eating disorder (ED) risk. Previous dissonance-based programs (i.e. the Body Project; BP) have successfully targeted thin-ideal internalization as an intervention mechanism. As burgeoning research indicates that fatphobia and anti-fat bias may play a central role in the maintenance of ED pathology, a focused intervention designed to target these constructs could bolster prevention efforts. The aims of this pilot study include confirming acceptability and feasibility of BAM and developing preliminary estimates of its effects on intervention targets, along with benchmarking these effects against the BP intervention. BAM was found to be accepted by participants and feasible to facilitate in a peer-led model. Preliminary results from 50 participants (BAM: N = 26; BP: N = 24) reveal small-to-moderate pre-to-post intervention effects on fatphobia, anti-fat bias, thin-ideal internalization, and eating pathology, which dissipated at 8-week follow-up. The BAM intervention has the potential to supplement the existing suite of ED prevention programs by specifically targeting anti-fat bias, though additional testing in larger and more diverse samples is necessary to clarify its impact on both hypothesized risk mechanisms and ED outcomes.

Fostering positive attitudes toward food in individuals with restrained eating: the impact of flexible food-related inhibition

Individuals exhibiting restrained eating behaviors demonstrate increased inhibitory control when exposed to food-related stimuli, indicating the presence of an automatic food-inhibition association. Existing literature proposes that this association contributes to the devaluation of food within this population. Efforts to disrupt this association by promoting the complete elimination of the inhibition of food responses have resulted in increased food consumption but have also led to heightened food-related anxiety in individuals with restrained eating behaviors. In the current investigation, we investigated whether a novel flexible food response/inhibition computerized task could yield favorable changes in attitudes toward food in individuals with restrained eating. We randomly assigned 78 females who engage in restrained eating to one of three training groups. In the flexible response/inhibition group, participants were instructed to equally inhibit or respond to food stimuli. In the response group, participants consistently responded to food stimuli, while in the inhibition group, participants consistently inhibited their response to food cues. Implicit attitudes toward food were assessed both before and after the manipulation. To examine the stability of the effect of the training, participants also engaged in a seemingly unrelated bogus taste test. Our results revealed that only the flexible response/inhibition group demonstrated a significant improvement in positive attitudes toward high-calorie foods after eating, while there were no observable changes in negative attitudes among the other two groups. These findings suggest that promoting a balance between the responding and inhibiting responses to food stimuli can increase positive attitudes toward food amongst individuals with restrained eating.

Measuring implicit associations between food and body stimuli in anorexia nervosa: a Go/No-Go Association Task

PURPOSE

The present study aimed to explore the implicit associations between food and bodily stimuli in patients with anorexia nervosa (AN) and control subjects (HC).

METHODS

A Go/No-Go Association Task was administrated to 55 participants (28 AN and 27 HC), using food stimuli (low-calorie food vs. high-calorie food) and body stimuli (underweight vs. overweight bodies).

RESULTS

We evidenced an implicit association between food and body stimuli in the AN group, whereas the HC group only showed a tendency. AN and HC groups also exhibited different categorization strategies: the AN group tended to categorize stimuli as low-calorie foods and underweight bodies less than the HC group, and they tended to categorize stimuli as high-calorie foods and overweight bodies more than the HC group.

CONCLUSION

The present study revealed for the first time specificities of the AN population's implicit association between food and body stimuli in terms of association strength and categorization strategy. Furthermore, the results suggest that combining implicit methodologies with other methods could contribute to a better characterization of the physiopathology of AN.

LEVEL OF EVIDENCE

Level I, experimental study.

Virtual Rejection and Overinclusion in Eating Disorders: An Experimental Investigation of the Impact on Emotions, Stress Perception, and Food Attitudes

(1) Background: the investigation of how interpersonal functioning affects eating psychopathology has been receiving increasing attention in the last decade. This study evaluates the impact of virtual social inclusion or ostracism on emotions, perceived stress, eating psychopathology, and the drive to binge or restrict in patients across the eating disorder spectrum. (2) Methods: a group of 122 adolescent and adult females with different eating disorder diagnoses were compared to 50 healthy peers with regards to their performance on, and responses to the Cyberball task, a virtual ball-tossing game. Each participant was randomly assigned to playing a social inclusion or a social exclusion block of the Cyberball task and completed self-report assessments of emotions, perceived stress and urge to restrict/binge before and after the task. (3) Results: patients with anorexia nervosa showed a more negative impact on psychological well-being evaluated with the need threat scale after the excluding block, while patients with bulimia nervosa reported more negative effects after the overincluding condition. Patients with binge eating disorder showed a reduction in specific negative emotions after the overincluding block, unlike all other participants. (4) Conclusions: findings show significant correlations between restraint thoughts in patients with bulimia nervosa and binge thoughts in patients with binge eating disorder after being exposed to the inclusion condition. Different reactions in cognitive and emotional states of patients with eating disorders after different interpersonal scenarios confirm the impact of inclusive or exclusive relationships on eating psychopathology, with specific and different responses across the eating disorder spectrum, that have been discussed, linked to their eating behavioral cognition.

Tasting inhibition: A proof-of-concept study of the food stop-signal game

Self-Control is an important skill in everyday life when attention is automatically drawn toward certain stimuli. For instance, food stimuli automatically capture visual attention and are processed preferentially. Therefore, efficient response inhibition is crucial to refrain from careless overeating. In the present proof-of-concept study we use a novel adaptation of a previously evaluated Stop-Signal Game (SSG) to measure reactive, food-specific, response inhibition in healthy adults. We analyzed a sample of 83 participants (60 female, mean age=24.1, mean BMI=21.71kg/m2) split into three groups. In a gamified stop-signal task, participants navigated an avatar in an urban environment toward high-calorie food, low-calorie food, or non-food stimuli in go-trials and were asked to inhibit the approach reaction in stop-trials. Hunger, eating styles, food craving, and impulsivity were assessed via self-reports to investigate their relationship with (food-specific) response inhibition. Results showed that response inhibition (in terms of stop-signal reaction time, SSRT) did not differ between the high-calorie, low-calorie, and non-food SSG which might be explained by characteristics of the sample. However, impulsivity was positively correlated with SSRT in the low-calorie SSG, whereas food-craving and hunger were positively related to response inhibition in the high-calorie SSG. Future studies could build upon the food SSG to measure and train food-specific response inhibition in the treatment of overeating.

Dismantling weight stigma in eating disorder treatment: Next steps for the field

The authors posit current guidelines and treatment for eating disorders (EDs) fail to adequately address, and often perpetuate, weight stigma. The social devaluation and denigration of higher-weight individuals cuts across nearly every life domain and is associated with negative physiological and psychosocial outcomes, mirroring the harms attributed to weight itself. Maintaining focus on weight in ED treatment can intensify weight stigma among patients and providers, leading to increased internalization, shame, and poorer health outcomes. Stigma has been recognized as a fundamental cause of health inequities. With no clear evidence that the proposed mechanisms of ED treatment effectively address internalized weight bias and its association with disordered eating behavior, it is not hard to imagine that providers' perpetuation of weight bias, however unintentional, may be a key contributor to the suboptimal response to ED treatment. Several reported examples of weight stigma in ED treatment are discussed to illustrate the pervasiveness and insidiousness of this problem. The authors contend weight management inherently perpetuates weight stigma and outline steps for researchers and providers to promote weight-inclusive care (targeting health behavior change rather than weight itself) as an alternative approach capable of addressing some of the many social injustices in the history of this field.

The sight of one’s own body: Could qEEG help predict the treatment response in anorexia nervosa?

Aims of the study

The study aims to identify the differences in brain activity between participants with anorexia nervosa and healthy control using visual stimulus conditions combined with the quantitative dense-array EEG recording analysis method called Brain Activation Sequences (BAS).

Materials and methods

23 participants with anorexia nervosa and 21 healthy controls were presented with visual stimuli, including the subject’s facial expressions and body images. The 128-channel EEG data were processed using BAS and displayed as activity in up to 66 brain regions. Subsequent cluster analysis was used to identify groups of participants exhibiting area-specific activation patterns.

Results

Cluster analysis identified three distinct groups: one including all healthy controls (HC) and two consisting of all participants with anorexia (AN-I with 19 participants and AN-II with four participants). The AN-I and AN-II groups differed in their response to treatment. Comparisons of HC vs. AN confirmed the dominance of the right cerebral hemisphere in participants with anorexia nervosa in two of the three reported conditions. The facial expressions condition, specifically the facial reaction expressing disgust, indicates the existence of a social attentional bias toward faces, whereas emotions remained undetected in participants. High limbic activity, medial frontal gyrus involvement, low fusiform cortex activity, and milder visual cortex activity in healthy controls compared to participants indicate that the facial expression stimulus is perceived by healthy subjects primarily as an emotion, not as the face itself. In the body image condition, participants showed higher activity in the fusiform gyrus and right insula, indicating activation of the brain’s “fear network.”

Conclusion

The study describes a specific pattern of brain activation in response to facial expression of disgust and body images that likely contributes to social-cognitive and behavioral impairments in anorexia. In addition, the substantial difference in the pattern of brain activation within the participants with AN and its association with treatment resistance deserves special attention because of its potential to develop a clinically useful prediction tool and identify potential targets for, for example, neuromodulatory treatments and/or individualized psychotherapy.

Time evaluation and its accuracy in eating disorders: differences in relation to interoceptive awareness

PURPOSE

Time evaluation has been poorly studied in eating disorder (ED) patients despite its relationship with body awareness, which is a core psychopathological feature in EDs and is influenced by impulsivity, interoception, and working memory. This study aims to evaluate time estimation and its accuracy across the ED spectrum in connection with specific and general psychopathology.

METHODS

A group of 215 women was enrolled in a computerized task involving the estimation of 1-min intervals. Impulsivity and body awareness constructs (self-monitoring, depersonalization, interoceptive deficit) were evaluated and examined for significant correlations with time estimation and the accuracy of the measure.

RESULTS

Patients with EDs showed an impaired ability to estimate time, with an accuracy that positively correlated with compulsive self-monitoring (p = 0.03). Differences between diagnostic subgroups showed an overestimation of time in anorexia nervosa patients and an underestimation of time in binge eating disorder patients, whose time estimation was also less accurate.

CONCLUSION

The relationship between time estimation and compulsive self- monitoring might corroborate the presence of an imbalanced integration of information in patients with EDs that was not present in the community women included in the study. Time perception should be further evaluated in the ED field, and longitudinal changes due to psychopathological recovery or BMI changes should be examined.

LEVEL OF EVIDENCE

Level III: Evidence obtained from a well-designed cohort or case-control analytic study.

Hidden cues for approach and avoidance motivation: implicit cognitive associations among patients with Nonadherence to HIV treatment

Although patient motivation related to HIV treatment is widely acknowledged as a key factor related to consistent adherence and engagement with medical care, research has predominantly focused on explicit rather than implicit cognitive processes that underlie motivation. This study identified and examined implicit cognitive processes that influence approach and avoidance treatment motivation in a sample of 30 HIV patients with suboptimal adherence and poor engagement with medical care. Study participants were predominantly African American (87%) and gay/bisexual (63%). We examined 173 thought statements about treatment collected from patients during two previous studies. Thematic analysis described how implicit cognitive associations influenced patients to approach or avoid treatment and medical care. Findings revealed three major contextual categories of treatment-related thoughts: links with routines and habits, connections to physical changes and reactions, and interpersonal associations. Within each category, implicit cognitive associations about treatment in terms of these daily life events and experiences cued approach and avoidance motivational tendencies without the patient's awareness. Findings from this study support the need for interventions that use implicit, less effortful approaches aimed at promoting adherence and improving the retention of patients with poor engagement.

Implicit approach-avoidance tendencies toward food and body stimuli absent in individuals with anorexia nervosa, bulimia nervosa, and healthy controls

OBJECTIVE

Body and food-related information are thought to activate cognitive biases and contribute to the maintenance of eating disorders (ED). Approach-avoidance biases may play an important role in the maintenance of dietary restriction and excessive food intake. Therefore, the present study aimed to examine approach-avoidance biases toward food and body stimuli in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and healthy controls (HC).

METHODS

The study included 42 individuals with AN, 24 individuals with BN, and 38 HCs. We used two implicit Approach-Avoidance Tasks (AAT) to assess approach-avoidance biases: participants completed a Food-AAT (high-calorie vs. low-calorie food) and a Body-AAT (thin vs. normal weight bodies). Additionally, explicit ratings of food and body stimuli were assessed.

RESULTS

There were no significant Group × Stimulus × Direction interactions in the implicit Food-AAT or implicit Body-AAT. In explicit ratings, individuals with AN and BN reported less urge to eat and more regret if they ate high-calorie and low-calorie food; individuals with AN and BN rated normal weight bodies as less normal weight, less attractive and less desirable than HCs. There were no group differences in explicit ratings of the thin body.

DISCUSSION

We did not find evidence for biased approach-avoidance tendencies toward food or body stimuli in individuals with AN or BN. Future studies are necessary to understand conflicting findings regarding approach-avoidance biases toward food and body stimuli in individuals with ED.

The KOALA-study: study protocol for a comprehensive study of cognitive biases in adolescent anorexia nervosa patients compared to healthy and clinical controls

BACKGROUND

Anorexia nervosa (AN) is characterized by dysfunctional cognitions including cognitive biases at various levels of information processing. However, less is known about the specificity of these biases, i.e., if they occur for eating-disorder-related information alone or also for non-eating-disorder-related emotional information in AN patients (content-specificity) and if they are unique to individuals with AN or are also shown by individuals with other mental disorders (disorder-specificity).

METHODS

The present study systematically assesses cognitive biases in 12-18-year-old female adolescents with AN on three levels of information processing (attention, interpretation, and memory) and with regard to two types of information content (eating-disorder-related, i.e., stimuli related to body weight and shape, and non-eating-disorder-related). To address not only content- but also disorder-specificity, adolescents with AN will be compared not only to a healthy control group but also to a clinical control group (adolescents with major depression or particular anxiety disorders). Cognitive biases are assessed within a single experimental paradigm based on the Scrambled Sentences Task. During the task eye movements are recorded in order to assess attention biases while interpretation biases are derived from the behavioural outcome. An incidental free recall test afterwards assesses memory biases. We expect adolescents with AN to show more pronounced negative cognitive biases on all three levels of information processing and for both types of content compared to healthy adolescents. In addition, we expect the specificity of biases to translate into differential results for the two types of content: AN patients are expected to show stronger biases for disorder-related stimuli but similar or less pronounced biases for non-disorder-related stimuli compared to the clinical control group.

DISCUSSION

This is the first study to comprehensively assess cognitive biases in adolescents with AN. It will have essential implications not only for cognitive-behavioural models of AN but also for subsequent studies aiming to modify cognitive biases in this population, thereby addressing important maintaining factors already at an early stage of the disorder.

All I Need Is Two: The Clinical Potential of Adding Evaluative Pairing Procedures to Cognitive Behavioral Therapy for Changing Self-, Body- and Food-Related Evaluations

Pairing procedures are among the most frequently used paradigms for modifying evaluations of target stimuli related to oneself, an object, or a specific situation due to their repeated pairing with evaluative sources, such as positive or negative images or words. Because altered patterns of evaluations can be linked to the emergence and maintenance of disordered cognitions and behaviors, it has been suggested that pairing procedures may provide a simple yet effective means of complementing more complex intervention approaches, such as cognitive behavioral therapy (CBT). Here, we summarize recent studies that explored the clinical potential of pairing procedures for improving self-esteem, body satisfaction, and food and consumption preferences. While no study has yet combined pairing procedures with CBT, there are several successful examples of pairing procedures in clinically relevant domains and clinical populations. We discuss potential sources of heterogeneity among findings, provide methodological recommendations, and conclude that pairing procedures may bear clinical potential as an add-on to classical psychotherapy.

Improving the touchscreen-based food approach-avoidance task: remediated block-order effects and initial findings regarding validity

Approach biases to foods may explain why food consumption often diverges from deliberate dietary intentions. Yet, the assessment of behavioural biases with the approach-avoidance tasks (AAT) is often unreliable and validity is partially unclear. The present study continues a series of studies that develop a task based on naturalistic approach and avoidance movements on a touchscreen (hand-AAT). In the hand-AAT, participants are instructed to respond based on the food/non-food distinction, thereby ensuring attention to the stimuli. Yet, this implies the use of instruction switches (i.e., 'approach food - avoid objects' to 'avoid food - approach objects'), which introduce order effects. The present study increased the number of instruction switches to potentially minimize order effects, and re-examined reliability. We additionally included the implicit association task (IAT) and several self-reported eating behaviours to investigate the task's validity. Results replicated the presence of reliable approach biases to foods irrespective of instruction order. Evidence for validity, however, was mixed: biases correlated positively with external eating, increase in food craving and aggregated image valence ratings but not with desire to eat ratings of the individual images considered within participants or the IAT. We conclude that the hand-AAT can reliably assess approach biases to foods that are relevant to self-reported eating patterns.

Exposure to the thin beauty ideal: Are there subliminal priming effects?

OBJECTIVE

Previous research suggested that exposure to the thin beauty ideal propagated by the media is associated with body dissatisfaction and the development of disordered eating. Given recent suggestions regarding the role of automatic processes, we aimed to enhance our understanding of automatic, unconscious responses to body pictures and the association with the internalization of the thin ideal and the severity of eating disorder symptoms.

METHOD

An affective priming task with body pictures of different weight as primes and a normal-weight body picture as target, which had to be evaluated with regard to attractiveness and desirability, was administered to healthy women with either subliminal prime presentation (Experiment 1) or conscious presentation (Experiment 2).

RESULTS

Subliminal presentation did not affect the evaluation of the normal-weight target, although strength of evaluative shifts was significantly associated with internalization of the thin ideal. In contrast, the conscious presentation of the ultra-thin prime decreased and of the obese prime increased desirability and attractiveness ratings of the target.

DISCUSSION

Prevention strategies focusing on the critical evaluation of the thin ideal are important. Future studies are warranted to enhance our understanding of automatic, unconscious processes in women experiencing eating disorders.

The implicit association of high-fat foods with shame and its link with eating disorder symptoms: The moderating role of race/ethnicity

BACKGROUND

An interesting debate in the literature is about the role of race/ethnicity not only as a risk factor for eating disorders (EDs), but also as a moderator of the relations between other risk factors and ED symptoms. The following research question was explored: Does race/ethnicity moderate the relations between the implicit belief that high-fat food is shameful and ED symptoms?

METHODS

About 15,000 (N = 14,964) volunteers (67.7% White, 7.7% Asian, 7.4% Hispanic, 6.9% Black) completed the Implicit Association Test (IAT) measuring the implicit associations between high-fat (vs. low-fat) food and shameful (vs. acceptable) on the Project Implicit mental-health website (https://implicit.harvard.edu) between 2011 and 2017. ED symptoms and demographics were measured via self-report.

RESULTS

Race/ethnicity moderated (beta = 0.087, p = .002) the relations between IAT and ED symptoms, adjusting for BMI, age, sex, education, such that the IAT was related to ED symptoms among Whites (r = 0.113, p < .001), Hispanics (r = 0.086, p = .004), and Asians (r = 0.097, p = .001), but not Blacks (r = 0.056, p = .071).

DISCUSSION

Although the effect size was small, findings imply that some ED risk factors may vary among racial/ethnic groups. Future studies should use prospective designs to examine whether implicit biases actually represent a risk factor for ED symptoms and whether this varies by race/ethnicity.