Effects of Cognitive Strategies on Neural Food Cue Reactivity in Adults with Overweight/Obesity

Cognitive reappraisal of food craving and emotions: a coordinate-based meta-analysis of fMRI studies

Growing evidence supports the effectiveness of cognitive reappraisal in down-regulating food desire. Still, the neural bases of food craving down-regulation via reappraisal, as well as their degree of overlap vs specificity compared with emotion down-regulation, remain unclear. We addressed this gap through activation likelihood estimation meta-analyses of neuroimaging studies on the neural bases of (i) food craving down-regulation and (ii) emotion down-regulation, alongside conjunction and subtraction analyses among the resulting maps. Exploratory meta-analyses on activations related to food viewing compared with active regulation and up-regulation of food craving have also been performed. Food and emotion down-regulation via reappraisal consistently engaged overlapping activations in dorsolateral and ventrolateral prefrontal, posterior parietal, pre-supplementary motor and lateral posterior temporal cortices, mainly in the left hemisphere. Its distinctive association with the right anterior/posterior insula and left inferior frontal gyrus suggests that food craving down-regulation entails a more extensive integration of interoceptive information about bodily states and greater inhibitory control over the appetitive urge towards food compared with emotion down-regulation. This evidence is suggestive of unique interoceptive and motivational components elicited by food craving reappraisal, associated with distinctive patterns of fronto-insular activity. These results might inform theoretical models of food craving regulation and prompt novel therapeutic interventions for obesity and eating disorders.

Engineering Virtuous health habits using Emotion and Neurocognition: Flexibility for Lifestyle Optimization and Weight management (EVEN FLOW)

Interventions to preserve functional independence in older adults are critically needed to optimize 'successful aging' among the large and increasing population of older adults in the United States. For most aging adults, the management of chronic diseases is the most common and impactful risk factor for loss of functional independence. Chronic disease management inherently involves the learning and adaptation of new behaviors, such as adopting or modifying physical activity habits and managing weight. Despite the importance of chronic disease management in older adults, vanishingly few individuals optimally manage their health behavior in the service of chronic disease stabilization to preserve functional independence. Contemporary conceptual models of chronic disease management and health habit theory suggest that this lack of optimal management may result from an underappreciated distinction within the health behavior literature: the behavioral domains critical for initiation of new behaviors (Initiation Phase) are largely distinct from those that facilitate their maintenance (Maintenance Phase). Psychological factors, particularly experiential acceptance and trait levels of openness are critical to engagement with new health behaviors, willingness to make difficult lifestyle changes, and the ability to tolerate aversive affective responses in the process. Cognitive factors, particularly executive function, are critical to learning new skills, using them effectively across different areas of life and contextual demands, and updating of skills to facilitate behavioral maintenance. Emerging data therefore suggests that individuals with greater executive function are better able to sustain behavior changes, which in turn protects against cognitive decline. In addition, social and structural supports of behavior change serve a critical buffering role across phases of behavior change. The present review attempts to address these gaps by proposing a novel biobehavioral intervention framework that incorporates both individual-level and social support system-level variables for the purpose of treatment tailoring. Our intervention framework triangulates on the central importance of self-regulatory functioning, proposing that both cognitive and psychological mechanisms ultimately influence an individuals' ability to engage in different aspects of self-management (individual level) in the service of maintaining independence. Importantly, the proposed linkages of cognitive and affective functioning align with emerging individual difference frameworks, suggesting that lower levels of cognitive and/or psychological flexibility represent an intermediate phenotype of risk. Individuals exhibiting self-regulatory lapses either due to the inability to regulate their emotional responses or due to the presence of executive functioning impairments are therefore the most likely to require assistance to preserve functional independence. In addition, these vulnerabilities will be more easily observable for individuals requiring greater complexity of self-management behavioral demands (e.g. complexity of medication regimen) and/or with lesser social support. Our proposed framework also intuits several distinct intervention pathways based on the profile of self-regulatory behaviors: we propose that individuals with intact affect regulation and impaired executive function will preferentially respond to 'top-down' training approaches (e.g., strategy and process work). Individuals with intact executive function and impaired affect regulation will respond to 'bottom-up' approaches (e.g., graded exposure). And individuals with impairments in both may require treatments targeting caregiving or structural supports, particularly in the context of elevated behavioral demands.

How images of food become cravingly salient in obesity

OBJECTIVE

This case-control study was aimed at testing two main hypotheses: (i) obesity is characterized by neurofunctional alterations within the mesocorticolimbic reward system, a brain network originating from the midbrain ventral tegmental area (VTA); and (ii) these alterations are associated with a bias for food-related stimuli and craving.

METHODS

Normal-weight individuals and individuals with obesity underwent a resting-state functional magnetic resonance imaging scan and the assessment of impulsivity, food craving, appetite, and implicit bias for food and non-food stimuli. The VTA was used as a seed to map, for each participant, the strength of its functional connections with the rest of the brain. The between-group difference in functional connectivity was then computed, and brain-behavior correlations were performed.

RESULTS

Individuals with obesity showed hyper-connectivity of the VTA with part of the ventral occipitotemporal cortex, recently found to be specialized for food images, and hypo-connectivity with the left inferior frontal gyrus, devoted to cognitive control. VTA-ventral occipitotemporal cortex connectivity was positively associated with food craving and food-related bias; the reverse correlation was observed for VTA-inferior frontal gyrus connectivity.

CONCLUSIONS

These findings reveal that, in obesity, food-related visual stimuli become cravingly salient through an imbalanced connectivity of the reward system with sensory-specific regions and the frontal cortex involved in cognitive control.

Habituation or sensitization of brain response to food cues: Temporal dynamic analysis in an functional magnetic resonance imaging study

Introduction

In the modern obesogenic environment, heightened reactivity to food-associated cues plays a major role in overconsumption by evoking appetitive responses. Accordingly, functional magnetic resonance imaging (fMRI) studies have implicated regions of the salience and rewards processing in this dysfunctional food cue-reactivity, but the temporal dynamics of brain activation (sensitization or habituation over time) remain poorly understood.

Methods

Forty-nine obese or overweight adults were scanned in a single fMRI session to examine brain activation during the performance of a food cue-reactivity task. A general linear model (GLM) was used to validate the activation pattern of food cue reactivity in food > neutral contrast. The linear mixed effect models were used to examine the effect of time on the neuronal response during the paradigm of food cue reactivity. Neuro-behavioral relationships were investigated with Pearson's correlation tests and group factor analysis (GFA).

Results

A linear mixed-effect model revealed a trend for the time-by-condition interactions in the left medial amygdala [t(289) = 2.21, β = 0.1, P = 0.028], right lateral amygdala [t(289) = 2.01, β = 0.26, P = 0.045], right nucleus accumbens (NAc) [t(289) = 2.81, β = 0.13, P = 0.005] and left dorsolateral prefrontal cortex (DLPFC) [t(289) = 2.58, β = 0.14, P = 0.01], as well as in the left superior temporal cortex [42 Area: t(289) = 2.53, β = 0.15, P = 0.012; TE1.0_TE1.2 Area: t(289) = 3.13, β = 0.27, P = 0.002]. Habituation of blood-oxygenation-level-dependent (BOLD) signal during exposure to food vs. neutral stimuli was evident in these regions. We have not found any area in the brain with significant increased response to food-related cues over time (sensitization). Our results elucidate the temporal dynamics of cue-reactivity in overweight and obese individuals with food-induced craving. Both subcortical areas involved in reward processing and cortical areas involved in inhibitory processing are getting habituated over time in response to food vs. neutral cues. There were significant bivariate correlations between self-report behavioral/psychological measures with individual habituation slopes for the regions with dynamic activity, but no robust cross-unit latent factors were identified between the behavioral, demographic, and self-report psychological groups.

Discussion

This work provides novel insights into dynamic neural circuit mechanisms supporting food cue reactivity, thereby suggesting pathways in biomarker development and cue-desensitization interventions.

Effects of mindset on hormonal responding, neural representations, subjective experience and intake

A person can alternate between food-related mindsets, which in turn may depend on one's emotional state or situation. Being in a certain mindset can influence food-related thoughts, but interestingly it might also affect eating-related physiological responses. The current study investigates the influence of an induced 'loss of control' mindset as compared to an 'in control' mindset on hormonal, neural and behavioural responses to chocolate stimuli. Mindsets were induced by having female chocolate lovers view a short movie during two sessions in a within-subjects design. Neural responses to visual chocolate stimuli were measured using an ultra-high field (7T) scanner. Momentary ghrelin and glucagon-like peptide 1 (GLP-1) levels were determined on five moments and were simultaneously assessed with self-reports on perceptions of chocolate craving, hunger and feelings of control. Furthermore, chocolate intake was measured using a bogus chocolate taste test. It was hypothesized that the loss of control mindset would lead to hormonal, neural and behavioural responses that prepare for ongoing food intake, even after eating, while the control mindset would lead to responses reflecting satiety. Results show that neural activity in the mesocorticolimbic system was stronger for chocolate stimuli than for neutral stimuli and that ghrelin and GLP-1 levels responded to food intake, irrespective of mindset. Self-reported craving and actual chocolate intake were affected by mindset, in that cravings and intake were higher with a loss of control mindset than with a control mindset. Interestingly, these findings suggest that physiology on the one hand (hormonal and neural responses) and behavior and subjective experience (food intake and craving) on the other hand are not in sync, are not equally affected by mindset.

A randomized controlled trial comparing prevention and promotion cognitive strategies in a behavioral weight-loss intervention

OBJECTIVE

Two approaches may shift attention from short-term rewards to longer-term weight-loss goals: focusing on long-term consequences of unhealthy choices (prevention) or benefits of healthy choices (promotion). This randomized controlled trial tested the impact of prevention- versus promotion-focused strategies in an internet-delivered behavioral weight-loss intervention (iBWL).

METHODS

A total of 95 participants with overweight/obesity were randomized to one of three 12-week iBWLs: (1) STANDARD (n = 31), (2) PREVENT (standard iBWL+prevention-focused training; n = 32), or (3) PROMOTE (standard iBWL+promotion-focused training; n = 32). Participants in the two enhanced arms were trained in their assigned strategy, and lessons and weekly feedback featured arm-specific content and reminders.

RESULTS

Intent-to-treat analysis revealed significant differences in weight loss and self-control use at 12 weeks (weight loss p = 0.002, self-control p = 0.0006). PREVENT was associated with 6.6% (±4.5%) weight loss and a 20.3% (±26.5%) increase in self-control, STANDARD and PROMOTE were associated with 4.4% (±4.2%) and 3.1% (±3.1%) weight losses, respectively, and neither STANDARD nor PROMOTE participants exhibited significant changes in self-control. Across arms, increased self-control was associated with greater weight loss (p = 0.0005).

CONCLUSIONS

Cognitive strategies to focus on preventing negative consequences of unhealthy choices led to greater weight loss and self-control compared with both standard iBWL and promotion-focused iBWL. Prevention strategies should be given further attention for overweight/obesity treatment.

A dismantling study on imaginal retraining in overweight or obese women

Imaginal retraining is a variant of approach bias modification and transfers the method into one's own mind. As the technique contains multiple elements, this pilot study aimed to dismantle which of its components is most efficient in reducing craving for high-calorie food. A total of 113 women were randomly allocated to one out of six conditions containing a short intervention to mentally manipulate a picture displaying high-calorie foods. Four of the interventions involved different combinations of elements of the imaginal retraining technique, while the remaining two conditions comprised thought suppression or merely observing a picture. Participants rated their level of craving, as well as three pictures containing healthy and unhealthy foods regarding their pleasantness before and after the interventions took place. Within-group changes were assessed with paired t-tests (in case of non-normal data Wilcoxon paired t-tests) and between-group differences with one-way ANOVAs (non-parametric Kruskal-Wallis tests). A trend level reduction in craving was found in the imaginal retraining condition with and without a movement. A post hoc analysis of both conditions joint together showed a statistically significant reduction in craving. In addition, positive picture appraisal for unhealthy foods was significantly reduced in both imaginal retraining conditions (with and without movement) with medium to large effect sizes. This study demonstrated that imaginal retraining with an arm movement can reduce craving and picture appraisal for high-calorie foods significantly in a one-time application. It is a promising technique to reduce appraisal for unhealthy high-calorie foods. Future studies should repeat the experiment in situations of high craving and allow for a personalized selection of stimuli.

Healthy decisions in the cued-attribute food choice paradigm have high test-retest reliability

Food choice paradigms are commonly used to study decision mechanisms, individual differences, and intervention efficacy. Here, we measured behavior from twenty-three healthy young adults who completed five repetitions of a cued-attribute food choice paradigm over two weeks. This task includes cues prompting participants to explicitly consider the healthiness of the food items before making a selection, or to choose naturally based on whatever freely comes to mind. We found that the average patterns of food choices following both cue types and ratings about the palatability (i.e. taste) and healthiness of the food items were similar across all five repetitions. At the individual level, the test-retest reliability for choices in both conditions and healthiness ratings was excellent. However, test-retest reliability for taste ratings was only fair, suggesting that estimates about palatability may vary more from day to day for the same individual.

Frontoparietal hyperconnectivity during cognitive regulation in obsessive-compulsive disorder followed by reward valuation inflexibility

Obsessive-compulsive disorder (OCD) is characterized by cognitive deficits and altered reward processing systems. An imbalance between cognitive and reward pathways may explain the lack of control over obsessions followed by rewarding compulsive behaviors. While the processes of emotional cognitive regulation are widely studied in OCD, the mechanisms of cognitive regulation of reward are poorly described. Our goal was to investigate the OCD impact on cognitive regulation of reward at behavioral and neural functioning levels. OCD and control participants performed a functional magnetic resonance imaging task where they cognitively modulated their craving for food pictures under three cognitive regulation conditions: indulge/increase craving, distance/decrease craving, and natural/no regulation of craving. After regulation, the participants gave each picture a monetary value. We found that OCD patients had fixed food valuation scores while the control group modulated these values accordingly to the regulation conditions. Moreover, we observed frontoparietal hyperconnectivity during cognitive regulation. Our results suggest that OCD is characterized by deficits in cognitive regulation of internal states associated with inflexible behavior during reward processing. These findings bring new insights into the nature of compulsive behaviors in OCD.

Sensory cue reactivity: Sensitization in alcohol use disorder and obesity

Neuroimaging techniques to measure the function of the human brain such as electroencephalography (EEG), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI), are powerful tools for understanding the underlying neural circuitry associated with alcohol use disorder (AUD) and obesity. The sensory (visual, taste and smell) paradigms used in neuroimaging studies represent an ideal platform to investigate the connection between the different neural circuits subserving the reward/executive control systems in these disorders, which may offer a translational mechanism for novel intervention predictions. Thus, the current review provides an integrated summary of the recent neuroimaging studies that have applied cue-reactivity paradigms and neuromodulation strategies to explore underlying alterations in neural circuitry as well in treatment strategies in AUD and obesity. Finally, we discuss literature on mechanisms associated with increased alcohol sensitivity post-bariatric surgery (BS) which offers guidance for future research to use sensory percepts in elucidating the relation of reward signaling in AUD development post-BS.

Regulating food craving: From mechanisms to interventions

Craving, defined here as a strong desire to eat, is a common experience that drives behavior. Here we discuss the concept of craving from historical, physiological, and clinical perspectives, and review work investigating the effects of cue reactivity and cue-induced craving on eating and weight outcomes, as well as underlying neural mechanisms. We also highlight the significance of cue reactivity and craving in the context of our "toxic food environment" and the obesity epidemic. We then summarize our work developing the Regulation of Craving (ROC) task, used to test the causal effects of cognitive strategies on craving for food and drugs as well as the underlying neural mechanisms of such regulation. Next, we review our recent development of a novel ROC-based intervention that trains individuals to use cognitive strategies to regulate craving, with promising effects on subsequent food choice and caloric consumption. We end by discussing future directions for this important line of work.