Cue exposure therapy reduces overeating of exposed and non-exposed foods in obese adolescents

The effects of a retrieval cue on renewal of conditioned responses in human appetitive conditioning

Contextual renewal of reward anticipation may be one potential mechanism underlying relapse in eating and substance use disorders. We therefore tested retrieval cues, a method derived from an inhibitory retrieval-based model of extinction learning to attenuate contextual renewal using an appetitive conditioning paradigm. A pilot study was carried out in Experiment 1 to validate a differential chocolate conditioning paradigm, in which a specific tray was set up as a conditioned stimulus (CS) for eating chocolate (unconditioned stimulus, US). Using an ABA renewal design in Experiment 2, half of the participants were presented with a retrieval cue in the acquisition phase (group AC) and the other half in the extinction phase (group EC). Presentation of the retrieval cue in the EC was associated with reduced renewal of US-expectancy, while there was a clear renewal effect for US-expectancy in the AC. One limitation was the difference in cue presentations between both groups due to the number of trials in acquisition and extinction. Experiment 3 therefore aimed at replicating the results of Experiment 2, but with fewer cue presentations for the EC to match the AC. No significant group differences were observed indicating no effect of the retrieval cue. Theoretical and clinical implications in light of the differing results are discussed.

Modified cue exposure for adolescents with binge eating behaviour: study protocol of a randomised pilot trial called EXI(ea)T

INTRODUCTION

Binge eating (BE) behaviour is highly prevalent in adolescents, and can result in serious metabolic derangements and overweight in the long term. Weakened functioning of the behavioural inhibition system is one potential pathway leading to BE. Food cue exposure focusing on expectancy violation (CE_EV) is a short intervention for BE that has proven effective in adults but has never been tested in adolescents. Thus, the current randomised pilot trial evaluates the feasibility of CE_EV for adolescents and its efficacy in reducing eating in the absence of hunger (EAH) of binge food items.

METHODS AND ANALYSIS

The trial will include N=76 female adolescents aged between 13 and 20 years with a diagnosis of bulimia nervosa, binge eating disorder (BED) or their subthreshold forms based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Participants will be randomly assigned to two sessions of CE_EV or behavioural analysis (BA), a classical cognitive-behavioural therapy-based intervention. The primary endpoint is the change in EAH measured according to ad libitum consumption of personally preferred binge food in a bogus taste test at post-test based on the intention-to-treat population. Key secondary endpoints are changes in EAH of standardised binge food at post-test, in EAH at 3-month follow-up (FU) and in food craving after induction of food cue reactivity at post-test and FU. To identify further valid outcome parameters, we will assess effects of CE_EV compared with BA on global ED psychopathology, BE frequency within the last 28 days, body weight, response inhibition and emotion regulation abilities. Treatment groups will be compared using analysis of covariance with intervention as fixed factor and body mass index at baseline as covariate.

ETHICS AND DISSEMINATION

This clinical trial has been approved by the Ethics Review Committee of the Medical Association of Rhineland-Palatinate and the Medical Faculty of the Ruhr-University Bochum. The collected data will be disseminated locally and internationally through publications in relevant peer-reviewed journals and will be presented at scientific and clinical conferences. Participants data will only be published in an anonymised form.

TRIAL REGISTRATION NUMBER

DRKS00024009.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

Factors Associated with Eating in the Absence of Hunger among Children and Adolescents: A Systematic Review

Eating in the absence of hunger (EAH) has been extensively studied over the past two decades and has been associated with excess body weight and the development of obesity. However, determinants of EAH remain uncertain. This systematic review aims to identify individual, familial, and environmental factors associated with EAH among children and adolescents. We included studies with a measure of EAH in participants aged 3-17 years old and including ≥1 factor associated with EAH. Our search identified 1494 articles. Of these, we included 81 studies: 53 cross-sectional, 19 longitudinal and nine intervention studies. In childhood (≤12 years old), EAH increases with age, it is greater in boys compared to girls, and it is positively associated with adiposity. Moreover, EAH development seems to be influenced by genetics. In adolescence, the number of studies is limited; yet, studies show that EAH slightly increases or remains stable with age, is not clearly different between sexes, and findings for overweight or obesity are less consistent across studies in adolescence. For familial factors, parental restrictive feeding practices are positively associated with EAH during childhood, mostly for girls. Studies assessing environmental factors are lacking and robust longitudinal studies spanning from early childhood to adolescence are needed.

Effect of a Novel Intervention Targeting Appetitive Traits on Body Mass Index Among Adults With Overweight or Obesity: A Randomized Clinical Trial

IMPORTANCE

Behavioral weight loss (BWL) programs result in weight loss for some, but most individuals regain the weight. The behavioral susceptibility theory proposes that genetically determined appetitive traits, such as food responsiveness (FR) and satiety responsiveness (SR), interact with the environment and lead to overeating and weight gain; the regulation of cues (ROC) intervention was developed specifically to target FR and SR.

OBJECTIVE

To evaluate the efficacy of ROC, ROC combined with BWL (ROC+), BWL, and an active comparator (AC) over 12 months of treatment and 12 months of follow-up.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted from December 2015 to December 2019 in a university clinic. A total of 1488 volunteers from the community inquired about the study; 1217 were excluded or declined to participate. Eligibility criteria included body mass index (BMI) of 25 to 45, age 18 to 65 years, and lack of comorbidities or other exclusionary criteria that would interfere with participation. Data were analyzed from September 2021 to January 2022.

INTERVENTIONS

ROC uniquely targeted FR and SR. BWL included energy restriction, increasing physical activity, and behavior therapy techniques. ROC+ combined ROC with BWL. AC included mindfulness, social support, and nutrition education.

MAIN OUTCOMES AND MEASURES

Change in body weight as measured by BMI.

RESULTS

A total of 271 adults (mean [SD] age, 46.97 [11.80] years; 81.6% female [221 participants]; mean [SD] BMI, 34.59 [5.28]; 61.9% White [167 participants]) were assessed at baseline, midtreatment, posttreatment, and 6-month and 12-month follow-up. Sixty-six participants were randomized to AC, 69 to ROC, 67 to ROC+, and 69 to BWL. Results showed that ROC, ROC+, and BWL interventions resulted in significantly lower BMI at the end of treatment (BMI ROC, -1.18; 95% CI, -2.10 to -0.35; BMI ROC+, -1.56; 95% CI, -2.43 to -0.67; BMI BWL, -1.58; 95% CI, -2.45 to -0.71). Compared with BWL, BMI at the end of treatment was not significantly different from ROC or ROC+ (BMI ROC, 0.40; 95% CI, -0.55 to 1.36; BMI ROC+, 0.03; 95% CI, -0.88 to 0.93); however, the BMI of the AC group was substantially higher (BMI AC, 1.58; 95% CI, 0.72 to 2.45). BMI reductions at 24 months after randomization were similar for ROC, ROC+, and BWL. Importantly, FR was a moderator of treatment effects with more weight loss for participants who scored higher in FR in the ROC and ROC+ groups.

CONCLUSIONS AND RELEVANCE

These findings suggest that ROC and ROC+ provide alternative weight loss approaches for adults. These models could be particularly effective for individuals who struggle with FR and could be used as a precision approach for weight loss.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02516839.

Problematic eating as an issue of habitual control

Obesity has reached alarming rates worldwide. Although many people attempt to control weight by modifying their food-related behaviours, this typically only has short-term effects and most dieters regain the weight that was lost. Why do so many people struggle to regulate their food-related behaviours? One possible explanation is that these behaviours have become habits that are not immediately sensitive to their consequences. Here we review experimental evidence for a shift to habitual control over food-related behaviours and the neural systems that control them and how this relates to difficulty changing ones' eating behavior.

Food reinforcement and habituation to food are processes related to initiation and cessation of eating

An individual bout of eating involves cues to start eating, as well as cues to terminate eating. One process that determines initiation of eating is food reinforcement. Foods with high reinforcing value are also likely to be consumed in greater quantities. Research suggests both cross-sectional and prospective relationships between food reinforcement and obesity, food reinforcement is positively related to energy intake, and energy intake mediates the relationship between food reinforcement and obesity. A process related to cessation of eating is habituation. Habituation is a general behavioral process that describes a reduction in physiological or affective response to a stimulus, or a reduction in the behavioral responding to obtain a stimulus. Repeated exposure to the same food during a meal can result in habituation to that food and a reduction in consumption. Habituation is also cross-sectionally and prospectively related to body weight, as people who habituate slower consume more in a meal and are more overweight. Research from our laboratory has shown that these two processes independently influence eating, as they can account for almost 60% of the variance in ad libitum intake. In addition, habituation phenotypes show reliable relationships with reinforcing value, such that people who habituate faster also find food less reinforcing. Developing a better understanding of cues to start and stop eating is fundamental to understanding how to modify eating behavior. An overview of research on food reinforcement, habituation and food intake for people with a range of weight status and without eating disorders is provided, and ideas about integrating these two processes that are related to initiation and termination of a bout of eating are discussed.

Differences in Food Craving in Individuals With Obesity With and Without Binge Eating Disorder

Overeating behavior is supposedly a major contributing factor to weight gain and obesity. Binge eating disorder (BED) with reoccurring episodes of excessive overeating is strongly associated with obesity. Learning models of overeating behavior and BED assume that mere confrontation with food leads to a conditioned response that is experienced as food craving. Accordingly, individuals with obesity and BED were shown to have high trait food cravings. To date, little is known about differences in state food cravings and cue reactivity at the sight of palatable food in individuals with obesity and BED compared to individuals with obesity without BED. Therefore, the aim of our study was to examine differences in cue-induced, state and trait food cravings in people with obesity with and without BED. We found that all aspects of food cravings were more prevalent in individuals with obesity and BED than in individuals without BED. By implementing a food cue reactivity paradigm, our results show that individuals with obesity with BED have more cue-induced cravings than individuals with obesity without BED. Moreover, these cue-induced cravings in individuals with obesity and BED were highest for high-fat and high-sugar foods as opposed to low-calorie foods. Thus, our results emphasize the role of increased cue reactivity and craving at the sight of palatable foods in individuals with obesity and BED. Hence, our findings support etiological models of conditioned binge eating and are in line with interventions targeting cue reactivity in BED.

The Empirical Status of Cue Exposure and Response Prevention Treatment for Binge Eating: A Systematic Review

Approximately 50% of individuals fail to obtain treatment benefits when undergoing cognitive-behavioral therapy (CBT) for binge-eating behaviors, making it necessary to evaluate additional approaches. Cue exposure and response prevention (CERP) is one such approach, although its effectiveness across studies has been inconsistent. This may be due to inconsistent implementation of theoretically based CERP strategies. This possibility has not yet been systematically investigated. To address this gap, this review investigated which CERP strategies have been incorporated into treatment protocols for binge eating, and if the use of certain strategies improves treatment effectiveness. Relevant studies were identified through reference lists, grey literature, and searches of electronic databases using multiple search terms related to CERP and binge eating, which resulted in 18 eligible studies. Most studies were underpowered, many were of low methodological quality, and none of the included studies utilized all of the strategies that have been recommended to optimize CERP. Despite these weaknesses, CERP appeared to reduce the frequency of binge eating in the short and long term. This review underscores the need for higher quality research that utilizes larger samples and uniform outcome measures that are more strongly grounded in theory. Such research would help improve treatment outcomes for binge eating.

Reevaluating Cue Exposure and Response Prevention in a Pilot Study: An Updated Treatment for Binge Eating Disorder

Approximately half of individuals with binge eating disorder (BED) fail to improve when treated with cognitive behavioral therapy; thus, better treatments are needed. Cue exposure and response prevention (CERP) may be one option, but its full potential for reducing binge eating remains unknown because prior applications for binge eating have not utilized the broad range of strategies believed to optimize exposure therapy. The current single-subject AB design investigated the acceptability and effectiveness of a comprehensive CERP treatment among 8 women who met DSM-5 criteria for binge eating disorder. Changes in the number of binges were measured from baseline to the end of treatment, and desire to eat, salivation, and idiographic expectancies of aversive outcomes to food-cue exposure (idiographic CS-US expectancies), including expectancies about ability to tolerate distress when exposed to food cues were measured across the course of treatment. Statistical analysis revealed a significant reduction in the number of binges from baseline to the end of treatment. Across the course of treatment, desire to eat and idiographic CS-US expectancies reduced, and distress tolerance expectancies increased. No participants dropped out and all reported being maximally satisfied with the treatment. Based on these findings, future randomized-control trials with larger samples should examine the efficacy of CERP and mechanisms underlying change with the aim of establishing a more effective treatment for binge eating disorder.

Individual differences in extinction learning predict weight loss after treatment: A pilot study

Learning theorists suggest extinction learning to be a central mechanism in weight loss success; however, empirical studies are scarce. In this pilot study, it was examined whether individual differences in extinction learning predict outcome after weight loss treatment. Overweight and obese individuals first completed a laboratory conditioning task in which individual differences in extinction learning were assessed. Next, they were randomised to one of two weight loss interventions: cue exposure therapy (CET), which is considered the clinical analogue of laboratory extinction, or a control lifestyle intervention. In line with expectations, better extinction learning in the laboratory task was associated with more weight loss at both post-treatment (CET only) and follow-up (both interventions) measurements. In contrast, two other indices of treatment success (reduction in overeating expectancies and ad libitum food intake during a laboratory taste test) showed no associations with pre-treatment extinction learning. It is suggested that extinction learning may be a core mechanism underlying weight loss success, and hence, an important target for new obesity interventions.

Exposure therapy vs lifestyle intervention to reduce food cue reactivity and binge eating in obesity: A pilot study

BACKGROUND AND OBJECTIVES

Learning models of overeating predict that exposure therapy is effective in reducing food cue reactivity and overeating. This pilot study tested an eight-session exposure therapy aimed at inhibitory learning vs. an active control condition aimed at lifestyle improvement for obesity (treatment-as-usual). Main outcomes are snacking behavior, eating psychopathology, food cue reactivity, and weight loss. Change in overeating expectancies was assessed as mediator for outcomes, and the associations between habituation of eating desires and outcomes were investigated in the exposure condition. Sleep quality was investigated as moderator for outcomes.

METHODS

45 overweight women were randomly assigned to the exposure intervention or control condition. The main outcomes, overeating expectancies and sleep quality were re-assessed at post-treatment and three-month follow-up. Habituation of eating desires was measured during exposure sessions.

RESULTS

Compared to the control intervention, exposure led to a significantly stronger reduction in snacking behavior of exposed foods, though this effect did not generalize to non-exposed foods, and stronger binge eating frequency. The exposure condition lost significantly more weight at post-treatment and follow-up than the lifestyle condition. Changes of expectancies mediated the effect of condition on kcal consumption of exposed foods, while habituation during exposure was not related to better treatment outcome. Sleep quality did not moderate the effect of condition on treatment outcome.

LIMITATIONS

Small sample size and limited follow-up period.

CONCLUSIONS

This short exposure therapy reduced snacking behavior, binge eating and weight more than a lifestyle intervention and is therefore a recommendable intervention for obesity and overeating disorders.

Laboratory-based interventions targeting food craving: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to quantify the effects of laboratory-based interventions targeting specific mechanisms of food craving, to identify moderators of effects, and to qualitatively summarize findings. The study was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Sixty-nine studies were included in the quantitative synthesis, and separate meta-analyses were conducted for the outcomes self-reported craving and objective food intake. Results show small to medium positive effects across specific craving interventions on both outcomes. Effect sizes were partly moderated by intervention type. The most effective intervention regarding food intake was in sensu cue exposure. For subjective craving, the most robust evidence was found for beneficial effects of cognitive regulation strategies (ie, reappraisal, suppression, and distraction). Results further indicate that training inhibitory control through behavioral inhibition might be more effective than approach-avoidance training when considering its effect on subjective craving and food intake. People with external eating habits, overeating, or loss-of-control eating might benefit from these types of specific craving interventions. Future research should focus on long-term effects, transferability, and effectiveness in clinical samples.

Rethinking Food Reward

The conscious perception of the hedonic sensory properties of caloric foods is commonly believed to guide our dietary choices. Current and traditional models implicate the consciously perceived hedonic qualities of food as driving overeating, whereas subliminal signals arising from the gut would curb our uncontrolled desire for calories. Here we review recent animal and human studies that support a markedly different model for food reward. These findings reveal in particular the existence of subcortical body-to-brain neural pathways linking gastrointestinal nutrient sensors to the brain's reward regions. Unexpectedly, consciously perceptible hedonic qualities appear to play a less relevant, and mostly transient, role in food reinforcement. In this model, gut-brain reward pathways bypass cranial taste and aroma sensory receptors and the cortical networks that give rise to flavor perception. They instead reinforce behaviors independently of the cognitive processes that support overt insights into the nature of our dietary decisions.

A new cognitive behavior therapy for adolescents with avoidant/restrictive food intake disorder in a day treatment setting: A clinical case series

OBJECTIVE

Avoidant/restrictive food intake disorder (ARFID) is a new diagnosis in the DSM-5 Feeding and Eating Disorders section, for which very limited treatment research has been carried out, yet. A new, 4-week exposure based cognitive behavioral therapy (CBT) day treatment, which integrated the inhibitory learning principles, was developed for adolescents with ARFID, and tested in the current study.

METHOD

A nonconcurrent multiple baseline design was used in a clinical case series of eleven 10- to 18-year-old patients. After baseline, the 4-week CBT followed. Measurements of DSM-5 ARFID diagnosis, food neophobia and related measures such as body weight and length, were taken at baseline (t1), at the end of the 4-week intensive day treatment (t2) and 3 months after treatment (follow-up, t3). A food selectivity test, a 1-week food diary, and behavioral measures on food intake were also taken at baseline and at 3-month follow-up. Furthermore, continuous measurements of believability of dysfunctional cognitions, anxiety, and food acceptance were taken throughout the 4-weeks day treatment.

RESULTS

At follow-up, 10 out of 11 patients were in remission and had a healthy body weight and an average, age-adequate nutritional intake. For most patients, food neophobia scores decreased to a nonclinical range. The belief in dysfunctional cognitions and anxiety levels decreased during treatment.

DISCUSSION

This new exposure-based CBT for adolescents with ARFID seems promising. These results may be very useful for clinical practice and stimulate further development of effective CBT interventions in the area of ARFID.

Learned Overeating: Applying Principles of Pavlovian Conditioning to Explain and Treat Overeating

PURPOSE OF REVIEW

This review provides an overview of recent findings relating to the role of Pavlovian conditioning in food cue reactivity, including its application to overeating and weight loss interventions.

RECENT FINDINGS

Both in the laboratory and in real life, cue-elicited appetitive reactivity (e.g., eating desires) can be easily learned, but (long-term) extinction is more difficult. New findings suggest impaired appetitive learning in obesity, which might be causally related to overeating. The clinical analogue of extinction-cue exposure therapy-effectively reduces cue-elicited cravings and overeating. While its working mechanisms are still unclear, some studies suggest that reducing overeating expectancies is important.

SUMMARY

Pavlovian learning theory provides a still undervalued theoretical framework of how cravings and overeating can be learned and how they might be effectively tackled. Future studies should aim to elucidate inter-individual differences in Pavlovian conditioning, study ways to strengthen (long-term) extinction, and investigate the working mechanisms of cue exposure therapy.