Computerized neurocognitive training for improving dietary health and facilitating weight loss

Self-control training supplementing inpatient multidisciplinary obesity treatment in children and adolescents

Research points to self-control as a possible mechanism for facilitating health behaviour and weight loss. The dual pathway model underpins the role of strong bottom-up reactivity towards food and weak top-down executive functions in obesity. Despite flourishing lab studies on attention bias modification or inhibition trainings, relatively few focused on training both processes to improve self-control in children and adolescents in inpatient multidisciplinary obesity treatment (MOT). Being part of the WELCOME project, this study investigated the effectiveness of Brain Fitness training (using the Dot Probe and Go/No-Go) as an adjunct to inpatient MOT in 131 Belgian children and adolescents. Changes in self-control (performance-based inhibitory control and attention bias as well as self-reported eating behaviour) in the experimental group were compared to sham training. Multiple Imputation was used to handle missing data. Inhibitory control and external eating improved over time (pre/post/follow-up), but we found no evidence for a significant interaction between time and condition. Future research should pay more attention to the role of individual variability in baseline self-control, sham training, and ecological validity of self-control training to improve real-life health behaviour and treatment perspectives for children and adolescents with weight problems.

Does virtual reality enhance the effects of inhibitory control training for loss-of-control eating? A pilot factorial experiment

Inhibitory control, one's ability to inhibit automatic responses to desirable stimuli, may be inadequately targeted in interventions for loss-of-control eating (LOC). Promising evidence has identified inhibitory control trainings (ICTs) as an avenue to target inhibitory control directly; however, effects of ICTs on real-world behavior are limited. Compared to typical computerized trainings, virtual reality (VR) presents several potential advantages that may address key shortcomings of traditional ICTs, i.e. poor approximation to everyday life. The present study utilized a 2 × 2 factorial design of treatment type (ICT vs sham) by treatment modality (VR vs standard computer), which allows for increased statistical power by collapsing across conditions. Our primary aim was to examine the feasibility and acceptability of six weeks of daily training among groups. A secondary aim was to preliminarily assess main and interactive effects of treatment type and modality on target engagement and efficacy (i.e., training compliance, change in LOC episodes, inhibitory control, and implicit liking of foods). Participants (N = 35) with ≥1×/weekly LOC were assigned to one of four conditions and completed ICTs daily for six weeks. The trainings were feasible and acceptable, evinced by high retention and compliance across time and condition. Although completing daily trainings across treatment types and modalities was associated with large decreases in LOC, there were no meaningful effects of either treatment type or modality, nor a significant interaction effect, on LOC or mechanistic variables. Future research should aim to increase the efficacy of ICT (both standard and VR-based) and test in fully-powered clinical trials.

Neural correlates underlying preference changes induced by food Go/No-Go training

Consistently not responding to appetitive foods during food go/no-go training could change individuals' food choices and sometimes even body weight, however, fewer studies have explored the neural pathways underlying the effects of food go/no-go training. In this study, we scanned eighty-six female participants using functional magnetic resonance imaging and investigated the neural bases of preference changes in a binary food choice task following action (e.g., go) or inaction (e.g., no-go) toward distinct foods within a food go/no-go training paradigm. In line with prior behavioral work, we found that participants' food preferences changed as a function of food go/no-go training, with participants choosing more "go" over "no-go" foods for consumption following training. At a neural level, preference changes were inversely associated with frontoparietal and salience network activity when choosing go (vs. no-go) foods. Additionally, task-related functional connectivities from the inferior parietal lobule to the pre-supplementary motor cortex, dorsolateral prefrontal cortex, and dorsal anterior cingulate cortex were related to these preference changes. Together, current work supports that food go/no-go training reliably changes people's preferences. More importantly, our findings suggest that a neural pathway centered on areas traditionally associated with selective attention may interface with prefrontal regions to guide preference changes induced by food go/no-go training, though future studies using other tasks (e.g., passive viewing tasks) are still needed to test this potential neural mechanism.

How does Go/No-Go training lead to food devaluation? Separating the effects of motor inhibition and response valence

Palatable, unhealthy food stimuli can be devalued via Go/No-Go (GNG) training that consistently pairs such stimuli with motor inhibition. However, it remains unclear whether this devaluation is caused via learned associations with motor inhibition or via inferential learning based on the valence of emitted motor responses. The present research disentangles the effects of motor assignment and response valence in GNG training through task instructions. In two studies, chocolate stimuli were consistently paired with motor inhibition ("no-go") or with motor excitation ("go"). Task instructions indicated that no-go responses were negatively valenced ("do not take") and that go responses were positively valenced ("take"), or identified no-go responses as positively valenced ("keep") and go as negatively valenced ("throw away"). The results show an effect of response valence on chocolate evaluations, but no effect of motor assignment: Chocolate stimuli were consistently devalued following pairings with a negatively valenced response, regardless of whether this response entailed motor inhibition or excitation. These findings align best with an inferential account of GNG training, suggesting that devaluation effects critically depend on inferential processes regarding motor response valence. GNG training procedures may, therefore, be optimised by disambiguating the valence of go and no-go motor responses prior to training.

Testing the effectiveness of a mobile approach avoidance intervention and measuring approach biases in an ecological momentary assessment context: study protocol for a randomised-controlled trial

INTRODUCTION

Unhealthy eating behaviour is a major contributor to obesity and related diseases and is associated with a behavioural bias to approach rather than avoid desired foods, as measured with reaction time tasks. Approach-avoidance interventions (AAIs) have been proposed as a way to modify food evaluations and help people to eat in accordance with their dietary goals. Mobile implementations of AAI might be easily accessible, low threshold interventions, but their effectiveness has not been established yet.

METHODS AND ANALYSIS

Participants who aim to change their eating behaviour are randomised to intervention or control groups. They complete six sessions of a smartphone-based AAI, in which they push (ie, avoid) or pull (ie, approach) personalised food images. Intervention group participants always avoid foods that they personally want to eat less often and approach foods that they personally want to eat more often. In the control group, images are paired equally often with both response directions. To evaluate contextual and dynamic intervention effects, ecological momentary assessment (EMA) is measured throughout, with questions about food intake, hunger, stress, emotions, eating intentions, food craving and impulsivity twice a day. Additional EMA preintervention and postintervention measures are administered before and after the intervention phase (4 days each) with a 1-day follow-up EMA 4 weeks after the intervention. Multilevel models will examine the temporal covariance between approach bias and self-reported variables as well as short-term and long-term intervention effects on approach bias, food intake and craving.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the University of Salzburg. Results will be published in peer-reviewed scientific journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

German Clinical Trials Register DRKS, registration number DRKS00030780.

Age-related differences in food-specific inhibitory control: Electrophysiological and behavioral evidence in healthy aging

The number of older adults in the United States is estimated to nearly double from 52 million to 95 million by 2060. Approximately 80-85% of older adults are diagnosed with a chronic health condition. Many of these chronic health conditions are influenced by diet and physical activity, suggesting improved diet and eating behaviors could improve health-related outcomes. One factor that might improve dietary habits in older adults is food-related inhibitory control. We tested whether food-related inhibitory control, as measured via behavioral data (response time, accuracy) and scalp-recorded event-related potentials (ERP; N2 and P3 components), differed between younger and older adults over age 55. Fifty-nine older adults (31 females [52.5%], M_age = 64, SD_age = 7.5) and 114 younger adults (82 females [71.9%], M_age = 20.8) completed two go/no-go tasks, one inhibiting to high-calorie stimuli and one inhibiting to low-calorie stimuli, while electroencephalogram (EEG) data were recorded. Older adults had slower overall response times than younger adults, but this was not specific to either food task. There was not a significant difference in accuracy between younger and older adults, but both groups' accuracy and response times were significantly better during the high-calorie task than the low-calorie task. For both the N2 and P3 ERP components, younger adults had larger no-go ERP amplitudes than older adults, but this effect was not food-specific, reflecting overall generalized lower inhibitory control processing in older adults. P3 amplitude for the younger adults demonstrated a specific food-related effect (greater P3 amplitude for high-calorie no-go than low-calorie no-go) that was not present for older adults. Findings support previous research demonstrating age-related differences in inhibitory control though those differences may not be specific to inhibiting towards food.

Pilot study of food-specific go/no-go training for overweight individuals: brain imaging data suggest inhibition shapes food evaluation

Food-specific go/no-go training might reduce overeating and facilitate weight loss. In this pilot study, we examined whether a food-specific go/no-go training over five weeks, as compared to a non-food-specific training, could produce changes in behavioral and neural responses to food images and body weight. Here, we used a sample of 51 overweight participants divided into training and control groups whose brain activity and food evaluation were measured before and after the training. Compared with the control group, in the training group we found significant reductions in high-calorie food evaluation. We also found lower activations in inhibitory control- and reward-related brain regions in response to high-calorie food images. Further, activation change of the mid-insula in response to the high-calorie food images was positively associated with change in the evaluation of those images. However, we found no evidence for a significant effect of food-specific go/no-go training on body weight change. Our findings highlight that food-specific go/no-go training in overweight individuals can reduce high-calorie food evaluation, but also neural activations in inhibitory control- and reward- related brain regions.

Efficacy of a food response and attention training treatment for obesity: A randomized placebo controlled trial

Elevated brain reward and attention region response, and weaker inhibitory region response to high-calorie foods has predicted future weight gain, suggesting that an intervention that reduces reward and attention region response and increases inhibitory region response to such foods might reduce overeating. We conducted a randomized controlled trial to test whether a multi-faceted food response and attention training protocol with personalized high- and low-calorie food images would reduce body fat and valuation and reward region response to high-calorie foods compared to a placebo control training protocol with non-food images in an effort to replicate findings from two past trials. Participants were community-recruited adults with overweight/obesity (N = 179; M age = 27.7 ± 7.0) who completed assessments at pretest, posttest, 3-month, 6-month, and 12-month follow-ups. Participants randomized to the food response inhibition and attention training showed significantly greater increases in palatability ratings of low-calorie foods than controls (d = 0.27) at posttest, but did not show body fat loss, reductions in palatability ratings and monetary valuation, or reward region response, to high-calorie foods. The lack of expected effects appears to be related to weaker learning compared to the learning in past trials, potentially because we used more heterogenous high-calorie and low-calorie food images in the present training.

Efficacy of a combined food-response inhibition and attention training for weight loss

This Current Opinion in Behavioral Sciences article reviews trials that evaluated an obesity treatment that combines response-inhibition training with high-calorie foods and training designed to reduce attention for high-calorie foods. Two randomized controlled trials suggest that food-response inhibition and attention training produced significant body-fat loss, along with a reduction in valuation of, and reward-region response to, high-calorie foods. However, these effects did not emerge in a third trial, potentially because this trial used more heterogeneous food images, which reduced inhibition learning and attentional learning. Collectively, results suggest that food-response inhibition and attention training can devalue high-calorie foods and result in weight loss, but only if a homogeneous set of high-calorie and low-calorie food images is used.

Exploring acute and non-specific effects of mobile app-based response inhibition training on food evaluation and intake

Previous studies have demonstrated that response inhibition training can modify the appeal of palatable and energy-dense foods, thus serving as a potential intervention for weight management, via changes in food selection and intake. However, empirical findings of efficacy have been inconsistent across studies due to heterogenous approaches to measuring salient appetitive outcomes, training implementation strategies, and sample recruitment. Systematic assessment of both affective and motivational components of food reward may help characterise to what extent devaluation can be generalised to nutritionally similar foods post-training. In this mixed factorial experiment, a non-clinical, adult sample completed time-matched single sessions with mobile app-based response inhibition training and control tasks of short (12 min; n = 27) or long (20 min; n = 25) duration. Participants were assessed on two discrete facets of food reward pre- and post-training: pleasure (i.e., explicit liking) and desire (i.e., implicit wanting) for non-specific (i.e., novel) food stimuli differing in energy-density. Consumption of snacks categorised by energy density was also assessed in a laboratory ad libitum taste test post-training. No significant differences were found between intervention and control sessions on explicit liking or implicit wanting for non-specific energy-dense foods. Moreover, participants ate a similar volume of snack foods during both sessions. Training duration did not significantly moderate differences between intervention and control sessions in primary outcomes. Variance between intervention and control sessions in chocolate intake and frequency of choice for energy-dense foods, but not explicit liking, was associated with a higher BMI. Methodological and theoretical implications for appropriate intervention implementation and underlying mechanisms, respectively, are discussed.

A Program for the Comprehensive Cognitive Training of Excess Weight (TRAINEP): The Study Protocol for A Randomized, Controlled Trial

Background: The available treatments for people with excess weight have shown small effects. Cognitive training has shown promising results, but most of the research focused on normal-weight university students and reported immediate results after a single training session. This parallel group, randomized, controlled trial aims to study the efficacy of a program for the comprehensive cognitive treatment of excess weight. Methods and Analysis: Participants will be 150 people with excess weight recruited through social media, who will be randomized into three groups: cognitive intervention, sham cognitive intervention, and treatment as usual. All assessment and intervention sessions will be online in groups of 5–6 participants. The three groups will attend a motivational interviewing session, and they will receive individualized diet and physical exercise guidelines throughout the program. The cognitive training will consist of four weekly sessions of approximately 60–90 min, each based on approach–avoidance bias training, inhibitory control training, implementation of intentions, and episodic future thinking, respectively. The main outcome measure will be a change in Body Mass Index (kg/m2). Secondary outcomes include changes in cognitive measures, eating and physical exercise behaviors, and anthropometric measures. Assessments will be conducted up to 6 months after the end of the program. In addition, data on the use of the health system will be collected to analyze the cost-effectiveness and the cost-utility of training. Linear mixed models will be used for statistical analysis. Findings of this study will expand the available evidence on cognitive interventions to reduce excess weight.

Gender differences in the effect of gamification on weight loss during a daily, neurocognitive training program

A major contributor to the obesity epidemic is the overconsumption of high-calorie foods, which is partly governed by inhibitory control, that is, the ability to override pre-prepotent impulses and drives. Computerized inhibitory control trainings (ICTs) have demonstrated qualified success at affecting real-world health behaviors, and at improving weight loss, particularly when repeated frequently over an extended duration. It has been proposed that gamification (i.e., incorporating game-like elements such as a storyline, sounds, graphics, and rewards) might enhance participant interest and thus training compliance. Previous findings from a mostly female sample did support this hypothesis; however, it might be expected that the effects of gamification differ by gender such that men, who appear more motivated by gaming elements, stand to benefit more from gamification. The present study evaluated whether gender moderated the effect of a gamified ICT on weight loss. Seventy-six overweight individuals received a no-sugar-added dietary prescription and were randomized to 42 daily and 2 weekly ICTs focused on sweet foods that were either gamified or nongamified. Results supported the hypothesis that gamification elements had a positive effect on weight loss for men and not women (p = .03). However, mechanistic hypotheses for the moderating effect (in terms of enjoyment, compliance, and improvements in inhibitory control) were generally not supported (p's > .20). These results suggest that gamification of ICTs may boost weight loss outcomes for men and not women, but further research is needed to determine the specific mechanisms driving this effect and to arrive at gamification elements that enhance effects for both men and women.

Targeting executive function for weight loss in adults with overweight or obesity

Obesity is associated with a multitude of negative health sequalae. Behavioral weight loss (BWL) is currently the recommended behavioral treatment for obesity; however, it is not effective for approximately half of the individuals who participate. BWL requires individuals to carry out many tasks requiring executive function (EF; i.e., higher order cognitive functions such as planning and problem solving) in order to be successful. Growing research supports that lower EF may be associated with attenuated weight loss following BWL, and targeting EF in treatment could improve outcomes. This paper aims to describe the rationale for the development of Novel Executive Function Training for Obesity (NEXT), which adapts Compensatory Cognitive Training to be delivered in conjunction with BWL. We summarize evidence relating EF to obesity and reduced weight loss following BWL, as well as the past success of cognitive training on EF. Then we describe the treatment model for NEXT followed by initial data suggesting that NEXT is feasible and acceptable and may impact EF and weight. Obesity treatments incorporating cognitive training, especially those that train compensatory strategies, may improve weight-loss outcomes and provide a more durable treatment than traditional interventions, but larger randomized control trials are necessary.

Food-related inhibitory control training reduces food liking but not snacking frequency or weight in a large healthy adult sample

Inhibitory control training has recently been used as an intervention to aid healthy eating and encourage weight loss. The aim of this pre-registered study was to explore the effects of training on food liking, food consumption and weight loss in a large (n = 366), predominantly healthy-weight sample. Participants received four training sessions within a week, in which they had to inhibit their responses to either energy-dense foods (active group) or non-food images (control group). Subjective food ratings, food consumption frequency and weight were measured pre- and post-training. At two-weeks post-training, the active group reported a greater reduction in liking for energy-dense foods, compared to the control group. Active participants also reported a significantly greater increase in healthy food liking, immediately post-training, relative to the control group. There was no statistically significant difference between groups for the change in consumption of trained foods or for weight loss. These findings are partially consistent with previous research conducted in smaller, more overweight samples. Exploratory analyses suggest that some effects of training may be driven by awareness effects. Methodological differences across findings and avenues for future investigation are discussed.

Modifying food items valuation and weight with gamified executive control training

Recent lines of research suggest that repeated executive control of motor responses to food items modifies their perceived value and in turn their consumption. Cognitive interventions involving the practice of motor control and attentional tasks have thus been advanced as potential approach to improve eating habits. Yet, their efficacy remains debated, notably due to a lack of proper control for the effects of expectations. We examined whether a one-month intervention combining the practice of Go/NoGo and Cue approach training modified the perceived palatability of food items (i.e. decrease in unhealthy and increase in healthy food items' palatability ratings), and in turn participants' weights. We assessed our hypotheses with a parallel, double-blind, randomized controlled trial. Motivation and adherence to the intervention were maximized by a professional-level gamification of the training tasks. The control intervention differed from the experimental intervention only in the biasing of the stimulus-response mapping rules, enabling to balance expectations between the two groups and thus to conclude on the causal influence of motoric control on items valuation. We found a larger decrease of the unhealthy items' palatability ratings in the experimental (20.6%) than control group (13.1%). However, we did not find any increase of the healthy items' ratings or weight loss. Overall, the present registered report confirms that the repeated inhibition of motor responses to food cues, together with the development of attentional biases away from these cues, reduces their perceived value.

App-based food Go/No-Go training: User engagement and dietary intake in an opportunistic observational study

Food Go/No-Go training aims to alter implicit food biases by creating associations between perceiving unhealthy foods and withholding a dominant response. Asking participants to repeatedly inhibit an impulse to approach unhealthy foods can decrease unhealthy food intake in laboratory settings. Less is known about how people engage with app-based Go/No-Go training in real-world settings and how this might relate to dietary outcomes. This pragmatic observational study investigated associations between the number of completed app-based food Go/No-Go training trials and changes in food intake (Food Frequency Questionnaire; FFQ) for different healthy and unhealthy food categories from baseline to one-month follow-up. In total, 1234 participants (m_(BMI) = 29 kg/m², m_(age) = 43years, 69% female) downloaded the FoodT app and completed food-Go/No-Go training at their own discretion (mean number of completed sessions = 10.7, sd = 10.3, range: 1-122). In pre-registered analyses, random-intercept linear models predicting intake of different foods, and controlled for baseline consumption, BMI, age, sex, smoking, metabolic syndrome, and dieting status, revealed small, significant associations between the number of completed training trials and reductions in unhealthy food intake (b = -0.0005, CI₉₅= [-0.0007;-0.0003]) and increases in healthy food intake (b = 0.0003, CI₉₅ = [0.0000; 0.0006]). These relationships varied by food category, and exploratory analyses suggest that more temporally spaced training was associated with greater changes in dietary intake. Taken together, these results imply a positive association between the amount of training completed and beneficial changes in food intake. However, the results of this pragmatic study should be interpreted cautiously, as self-selection biases, motivation and other engagement-related factors that could underlie these associations were not accounted for. Experimental research is needed to rule out these possible confounds and establish causal dose-response relationships between patterns of engagement with food Go/No-Go training and changes in dietary intake.

Preserved Inhibitory Control Deficits of Overweight Participants in a Gamified Stop-Signal Task: Experimental Study of Validity

Background

Gamification in mental health could increase training adherence, motivation, and transfer effects, but the external validity of gamified tasks is unclear. This study documents that gamified task variants can show preserved associations between markers of behavioral deficits and health-related variables. We draw on the inhibitory control deficit in overweight populations to investigate effects of gamification on performance measures in a web-based experimental task.

Objective

This study tested whether associations between inhibitory control and overweight were preserved in a gamified stop-signal task (SST).

Methods

Two versions of an adaptive SST were developed and tested in an online experiment. Participants (n=111) were randomized to 1 of the 2 task variants and completed a series of questionnaires along with either the gamified SST or a conventional SST. To maximize its possible effects on participants’ inhibitory control, the gamified SST included multiple game elements in addition to the task itself and the stimuli. Both variants drew on the identical core mechanics, but the gamified variant included an additional narrative, graphical theme, scoring system with visual and emotional feedback, and the presence of a companion character. In both tasks, food and neutral low-poly stimuli were classified based on their color tone (go trials), but responses were withheld in 25% of the trials (stop trials). Mean go reaction times and stop-signal reaction times (SSRT) were analyzed as measures of performance and inhibitory control.

Results

Participants in the gamified SST had longer reaction times (803 [SD 179] ms vs 607 [SD 90] ms) and worse inhibitory control (SSRT 383 [SD 109] ms vs 297 [SD 45] ms). The association of BMI with inhibitory control was relatively small (r=.155, 95% CI .013-.290). Overweight participants had longer reaction times (752 [SD 217] ms vs 672 [SD 137] ms) and SSRTs (363 [SD 116] ms vs 326 [SD 77] ms). Gamification did not interact with the effect of overweight on mean performance or inhibitory control. There were no effects of gamification on mood and user experience, despite a negative effect on perceived efficiency.

Conclusions

The detrimental effects of heightened BMI on inhibitory control were preserved in a gamified version of the SST. Overall, the effects of overweight were smaller than in previously published web-based and laboratory studies. Gamification elements can impact behavioral performance, but gamified tasks can still assess inhibitory control deficits. Although our results are promising, according validations may differ for other types of behavior, gamification, and health variables.

Improving Treatment Outcome in Children With Obesity by an Online Self-Control Training: A Randomized Controlled Trial

Background: Currently available treatment programs for children with obesity only have modest long-term results, which is (at least partially) due to the poorer self-control observed within this population. The present trial aimed to determine whether an online self-control training, training inhibition, and redirecting attentional bias, can improve the short- and long-term treatment outcome of (in- or outpatient) child obesity treatment programs. Methods: In this double-blind multi-center randomized controlled trial (RCT), participants aged 8-18 years with obesity were allocated in a 1:1 ratio to receive an online self-control or sham training added to their in- or outpatient multidisciplinary obesity treatment (MOT) program. The primary endpoint was BMI SDS. Data were analyzed by linear mixed models and the main interactions of interest were randomization by time and randomization by number of sessions, as the latter was cumulatively expressed and therefore represents the effect of increasing dose over time. Results: One hundred forty-four inpatient (mean age 14.3 ± 2.2 years, BMI 2.7 ± 0.4 SDS, 42% male) and 115 outpatient children (mean age 11.9 ± 2.1 years, BMI 2.4 ± 0.4 SDS, 45% male) were included. Children's BMI lowered significantly during treatment in both the in- and outpatient treatment centers, p < 0.001. In a mixed model with BMI as dependent variable, randomization by time was non-significant, but the number of self-control trainings (randomization ^* number of sessions) interacted significantly with setting and with age (p = 0.002 and p = 0.047), indicating a potential effect in younger inpatient residents. Indeed, a subgroup analysis on 22 inpatient children of 8-12 years found a benefit of the number of self-control trainings on BMI (p = 0.026). Conclusions: The present trial found no benefit of the self-control training in the entire study population, however a subgroup of young, inpatient participants potentially benefited.

Examining cognitive bias modification interventions for reducing food value and choice: Two pre-registered, online studies

There is considerable interest in Cognitive Bias Modification (CBM) as a potential treatment for overweight/obesity. Inhibitory Control Training (ICT: also known as motor response training) and Evaluative Conditioning (EC) are two popular paradigms which rely on associatively learned responses (unhealthy food - > inhibition, or unhealthy food- > negative stimulus, respectively) through repeated cue-response contingencies. Both ICT and EC have demonstrated some effectiveness for reducing food intake, value and/or choice, when administered in the laboratory and online. However, studies have been criticised for inconsistencies in design (e.g. use of inadequate control groups) which makes it difficult to draw robust conclusions. In two pre-registered, online studies our aim was to examine active ICT (study 1: N = 170) and EC (study 2: N = 300) in multiple groups where the cue- > response contingencies were systematically varied (100%, 75%, 50%, 25%), before examining food-cue valuations and hypothetical food choice. In both studies varying the cue- > response contingencies did not lead to significant changes in food-cue devaluation following training. ICT did not substantially influence hypothetical food choice, whereas there was weak evidence that EC reduced choice for unhealthy foods, compared to a control group with 50% cue-response contingencies. Taken together both studies provide limited evidence for online CBM as a viable psychological treatment - at least through the mechanism of food-cue devaluation or changes in healthy and unhealthy food choice. Future research is needed to investigate the factors that contribute towards successful CBM training to critically evaluate the potential for these strategies within interventions.

Using virtual reality to train inhibitory control and reduce binge eating: A proof-of-concept study

OBJECTIVE

One reason for limited efficacy of treatments for binge eating disorder (BED) and bulimia nervosa (BN) is a failure to directly target deficits in inhibitory control (i.e., the ability to withhold a pre-potent response). Inhibitory control trainings (ICTs; computerized tasks meant to improve inhibitory control) have shown promise but appear not to be powerful enough to generalize to real-word eating behavior or engaging enough for to sustain long-term compliance. Delivering an ICT through virtual reality (VR) technology should increase intervention power because 3D imagery and actual real hand/arm movements are lifelike and may improve compliance because the VR environment is highly engaging. Thus, we created the first-ever VR-based ICT to test its initial feasibility, acceptability, and impact on binge eating.

METHOD

We recruited participants (N = 14) with once-weekly loss-of-control (LOC) eating to use the VR ICT daily, at home, for two weeks, and measured feasibility, acceptability and change in LOC eating at post-intervention and 2-week follow-up.

RESULTS

The VR ICT was feasible to construct and deploy, and demonstrated high acceptability and compliance (i.e., 86.8% of daily trainings completed). Users of the VR ICT experienced large decreases in LOC eating at post-intervention and 2-week follow-up.

DISCUSSION

Results from this initial pilot indicate that delivering ICT through VR is feasible, acceptable, and is associated with reductions in binge eating. Future study is warranted and should examine whether a VR ICT can serve as a useful adjunct to standard treatment for BN and BED.

Three minutes to change preferences: perceptual fluency and response inhibition

Perceptual fluency and response inhibition are well-established techniques to unobtrusively manipulate preference: objects are devalued following association with disfluency or inhibition. These approaches to preference change are extensively studied individually, but there is less research examining the impact of combining the two techniques in a single intervention. In short (3 min) game-like tasks, we examine the preference and memory effects of perceptual fluency and inhibition individually, and then the cumulative effects of combining the two techniques. The first experiment confirmed that perceptual fluency and inhibition techniques influence immediate preference judgements but, somewhat surprisingly, combining these techniques did not lead to greater effects than either technique alone. The second experiment replicated the first but with changes to much more closely imitate a real-world application: measuring preference after 20 min of unrelated intervening tasks, modifying the retrieval context via room change, and generalization from computer images of objects to real-world versions of those objects. Here, the individual effects of perceptual fluency and inhibition were no longer detected, whereas combining these techniques resulted in preference change. These results demonstrate the potential of short video games as a means of influencing behaviour, such as food choices to improve health and well-being.

Go/no-go for food: Attention bias and intention to eat unhealthy food

OBJECTIVE

The current research evaluated whether Go/No-go training for highly palatable (HP) food affected attention bias for HP food (an automatic/implicit outcome) and intention to eat unhealthy food (a controlled/explicit outcome).

METHOD

A sample of Australian adults representative for age, gender and Body Mass Index (BMI) (N = 561, M_age = 46.31 years, SD = 16.75, 52.3% women, M_BMI = 27.11, SD = 6.34) completed self-report measures of dietary psychological constructs and food image modified Stroop tasks as measures of pre- and post-test attention bias for HP food. After random assignment of participants to two conditions, a Go/No-go intervention was used to train HP food targeted inhibitory control in the experimental group, or general inhibitory control in the control group. All research tasks were delivered online.

RESULTS

The experimental, HP food inhibitory control training group reported intention to eat less unhealthy food than the control group, F (1, 637) = 4.81, R² = 0.09, p = .029. Counter to expectations, the experimental group exhibited a heightened attention bias to HP food images after the training, F (1, 637) = 9.48, R² = 0.39, p = .002.

CONCLUSION

Go/No-go training for food may improve both top-down and bottom-up inhibitory control, using both automatic and controlled processes. Further, it may not be effective in lowering attention bias for HP food, but may be effective in lowering unhealthy food intake despite raising attention bias for HP food. Further research that tests these effects using varied reaction time tasks is needed to confirm these results and to explore possible alternative explanations.

The project REBOOT protocol: Evaluating a personalized inhibitory control training as an adjunct to cognitive behavioral therapy for bulimia nervosa and binge-eating disorder

Outcomes from cognitive behavioral therapy (CBT) for bulimia nervosa (BN) and binge-eating disorder (BED) are suboptimal. One potential explanation is that CBT fails to adequately target inhibitory control (i.e., the ability to withhold an automatic response), which is a key maintenance factor for binge eating. Computerized inhibitory control training (ICT) is a promising method for improving inhibitory control but is relatively untested in BN/BED. The present study will evaluate a computer-based ICT as an adjunct to CBT for BN/BED. Participants with BN (n = 30) or BED (n = 30) will be randomized to 12 weeks of either CBT + ICT or CBT + a sham training. Trainings will be completed daily for 4 weeks and weekly for 8 weeks. Primary aims include the following: (a) confirm target engagement (evaluate whether ICT improves inhibitory control), (b) test target validation (evaluate whether improvements in inhibitory control are associated with improvements in binge eating), and (c) evaluate the incremental efficacy of ICT on binge eating. Secondary aims include the following: (a) evaluate ICT feasibility and acceptability and (b) assess the moderating effects of approach tendencies on highly palatable food, dietary restraint, and diagnosis. Data will be used to shape a fully powered clinical trial designed to assess efficacy and dose-response effects of ICT for BN/BED.

The momentary interplay of affect, attention bias, and expectancies as predictors of binge eating in the natural environment

OBJECTIVE

Affect regulation, eating expectancies, and attention toward food-related cues are interrelated constructs that have been implicated in the maintenance of binge eating. While these processes show considerable temporal variability, the momentary associations between these domains have not been elucidated. This study examined a model that posited momentary fluctuations in affect, eating expectancies, and attention bias (AB) would interact to predict subsequent binge eating.

METHOD

Forty women who endorsed recurrent binge eating completed a 10-day ecological momentary assessment protocol with ambulatory measures of AB (i.e., dot-probe task with palatable food and neutral cues) and self-report assessments of positive and negative affect, eating expectancies (i.e., the belief that eating would improve one's mood), and binge-eating symptoms.

RESULTS

Generalized linear mixed models indicated higher momentary AB toward palatable food was associated with increased risk of subsequent binge eating, and a two-way interaction showed that moments of higher eating expectancies and negative affect were associated with increased likelihood of subsequent binge eating. Also, a three-way interaction emerged, in that the association between eating expectancies and subsequent binge eating was strongest at lower levels of positive affect and higher AB.

DISCUSSION

Together, findings partially supported hypotheses and demonstrate meaningful within-person fluctuations in AB that precede binge eating. Further, results demonstrate that the momentary influence of eating expectancies on binge eating depends on both affective state and attentional processes.

Cognitive and environmental interventions to encourage healthy eating: evidence-based recommendations for public health policy

Policymakers are focused on reducing the public health burden of obesity. The UK average percentage of adults classified as obese is 26%, which is double that of the global average. Over a third of UK adults report using at least one weight management aid. Yet, many people still struggle to change their diet-related behaviour, despite having the awareness, intention and capability to do so. This 'intention-behaviour gap' may be because most existing dietary-choice interventions focus on individual decision-making, ignoring the effects of environmental cues on human behaviour. Behaviour change interventions that 'nudge' people into making healthier choices by modifying the food environment have been shown to be effective. However, this type of intervention is typically challenging for policymakers to implement for economic, ethical and public accessibility reasons. To overcome these concerns, policymakers should consider 'boosting' interventions. Boosting involves enhancing competences that help people make decisions consistent with their goals. Here, we outline cognitive training as a boosting intervention to tackle obesity. We synthesize the evidence for one type of cognitive training (go/no-go training) that may be effective at modifying food-related decisions and reducing body weight. We offer evidence-based recommendations for an obesity-focused Public Health Wales behaviour change programme.