Modifying food items valuation and weight with gamified executive control training

Generalization of food devaluation following food-specific go/no-go training

The benefit of food-specific inhibition training on modulating food valuation and eating behaviors has been established, but generalization to untrained foods is seldomly examined. This study investigated whether stimulus variability and practice order, found to effect generalization in motor learning, can improve generalization following food-specific inhibition training. Ninety-three young adults practiced the Go/No-Go task online in three training conditions: 1) Constant (N = 30): inhibition practiced on one food stimulus; 2) Variable-Blocked (N = 32): inhibition practiced on 6 food stimuli, each in a separate block; and 3) Variable-Random (N = 31): inhibition practiced on 6 food stimuli in random order. Consistent with our hypothesis, the Variable-Random group showed better generalization of inhibition to untrained foods than the Constant and the Variable-Blocked groups immediately after training, demonstrating the benefit of stimulus variability and random practice order. This effect was not present 24 h after training. The Variable-Random group also showed decreased desire to eat untrained foods, exhibiting generalization of food devaluation. However, this effect was only present 24 h after training. The Constant group showed increased desire to eat untrained foods immediately and 24 h after training. The Variable-Blocked group did not differ from either group in the desire to eat to untrained foods, suggesting that random order is important for exposing the benefit of variability. The findings illustrate that presenting various training items in random order can improve generalization of food-specific inhibition training. However, inconsistencies found in the timing of generalization effects and modest effect sizes warrant additional investigation into generalization principles of food-specific inhibition training.

Response inhibition training as an intervention to modify liking and wanting for foods based on energy density: a proof of concept study

The ubiquity of energy-dense, processed foods has been implicated as a salient feature of the modern 'obesogenic' environment. Cognitive strategies, such as response inhibition training, have been demonstrated to reduce the hedonic value of such foods in previous studies. However, this effect has generally been inconsistent or heterogenous, depending on the outcome measure, characteristics of the sample, and the specificity of food stimuli. Characterising the extent of generalised effects may help define the application of this type of intervention in natural settings. A repeated-measures, proof-of-concept study, using mobile app-based response inhibition training (RIT) versus a control app-based activity (N = 25), was undertaken to establish the valid application of a food reward measure to assess intervention efficacy. Liking (i.e., affect) and wanting (i.e., motivation) for food stimuli categorised by energy density were taken concurrently pre- and post-training. A statistically significant reduction in explicit liking, but not implicit wanting, for foods irrespective of their energy density was observed during the RIT app-based training session relative to the control (p = .041, ηp2 = .16). However, effect sizes associated with devaluation of energy-dense relative to low calorie food stimuli, although non-significant, were higher when measured as implicitly wanting (p = .098, ηp2 = .11) than explicit liking (p = .756, ηp2 = .00). Trends in explicit stimulus evaluations were empirically discordant from implicit evaluations for low calorie foods in particular. Additional research is needed to investigate whether these trends are reproducible with larger samples, trained and novel food stimuli in outcome measures, and more comprehensive training protocols.

Can smartphone-based response inhibition training elicit sustained changes in appetite, preference, and cravings for energy-dense foods? A free-living randomized controlled trial

BACKGROUND

Food-specific response inhibition training has been implemented as a strategy to modify food choices and reward-related eating behaviours, but short-term studies have produced equivocal findings.

OBJECTIVE

To longitudinally assess the effect of a smartphone-based response inhibition intervention on food reward, hedonic eating drive, and cravings in a free-living setting.

METHODS

84 adults (Mage  = 30.49, SDage  = 13.01, 52 female) with high responsivity to food cues or overweight/obesity were randomly assigned to a response inhibition training intervention (n = 45) or a control game (n = 39) at home during a training week, followed by a week with no training. Primary analyses compared groups on measures of explicit liking and implicit wanting for food of different energy densities, food cravings, and reward-related eating throughout this two-week period.

RESULTS

A reduction was observed in explicit liking and implicit wanting for energy-dense foods from baseline to post-training independent of condition (ps < .001). These changes from baseline were sustained after a 1-week latency period, also independent of condition (ps < .001). These effects coincided with similar observations of hedonic eating drive, tonic cravings, and control over cravings during the observation period (ps < .01).

CONCLUSIONS

Although significant reductions in reward-related appetite were observed, free-living response inhibition training did not offer additional benefit over a control activity. Future intervention studies with observable food intake are needed to investigate which appetitive mechanisms most reliably predict eating behaviour over time.

TRIAL REGISTRATION

Retrospectively registered with ANZCTR [ACTRN12622001502729].

Be more mindful: Targeting addictive responses by integrating mindfulness with cognitive bias modification or cue exposure interventions

This review provides an overview of the most prominent neurocognitive effects of cognitive bias modification (CBM), cue-exposure therapy and mindfulness interventions for targeting addictive responses. It highlights the key insights that have stemmed from cognitive neuroscience and brain imaging research and combines these with insights from behavioural science in building a conceptual model integrating mindfulness with response-focused CBM or cue-exposure interventions. This furthers our understanding of whether and how mindfulness strategies may i) facilitate or add to the induced response-focused effects decreasing cue-induced craving, and ii) further weaken the link between craving and addictive responses. Specifically, awareness/monitoring may facilitate, and decentering may add to, response-focused effects. Combined awareness acceptance strategies may also diminish the craving-addiction link. The conceptual model presented in this review provides a specific theoretical framework to deepen our understanding of how mindfulness strategies and CBM or cue-exposure interventions can be combined to greatest effect. This is important in both suggesting a roadmap for future research, and for the further development of clinical interventions.

When not responding to food changes food value: The role of timing

Establishing behavior change toward appetitive foods can be crucial to improve people's health. Food go/no-go training (GNG), in which people respond to some food items and not to other food items depending on the presentation of a go or no-go cue, is a means to establish behavior change. GNG changes the perceived value of food items and food consumption. After GNG, no-go items are rated as less attractive than go and/or untrained items, an empirical phenomenon called the NoGo-devaluation-effect. This effect is not always found, however. One theory-based explanation for these inconsistent results may be found in the timing of the go and no-go cues, which is also inconsistent across studies. Hence, in the present work we conducted two experiments to examine the possible role of go and no-go cue presentation timing in eliciting the NoGo-devaluation-effect. In Experiment 1, we presented the food items before the presentation of go/no-go cues, whereas we reversed this order in Experiment 2. As predicted, the NoGo-devaluation-effect was obtained in Experiment 1. This effect was absent in Experiment 2. Moreover, recognition memory for stimulus-action contingencies moderated the devaluation effect in Experiment 1, but not in Experiment 2. These results show that NoGo devaluation is dependent on the timing of the NoGo cue, which has theoretical and applied implications for understanding how and when go/no-go training influences food consumption. We propose that the value of food items is updated during go/no-go training to minimize prediction errors, and that this updating process is boosted by attention.

Reduction in sugar drink valuation and consumption with gamified executive control training

The overvaluation of high-energy, palatable food cues contributes to unhealthy eating and being overweight. Reducing the valuation of unhealthy food may thus constitute a powerful lever to improve eating habits and conditions characterized by unhealthy eating. We conducted a double-blind, placebo-controlled, randomized intervention trial assessing the efficacy of a five to twenty days online cognitive training intervention to reduce sugary drink perceived palatability and consumption. Our intervention involved a recently identified action-to-valuation mechanism of action, in which the repeated inhibition of prepotent motor responses to hedonic food cues in a Go/NoGo (GNG) and an attentional bias modification (ABM) task eventually reduces their valuation and intake. Confirming our hypotheses, the experimental intervention with consistent (100%) mapping between motor inhibition and the targeted unhealthy sugary drinks cues induced a larger decrease in their valuation than the control intervention with inconsistent (50%) mapping (- 27.6% vs. - 19%), and a larger increase of the (water) items associated with response execution (+ 11% vs + 4.2%). Exploratory analyses suggest that the effect of training on unhealthy items valuation may persist for at least one month. Against our hypothesis, we observed equivalent reductions in self-reported consumption of sugary drinks following the two interventions (exp: - 27% vs. ctrl: - 19%, BF01 = 4.7), suggesting a dose-independent effect of motor inhibition on self-reported consumption. Our collective results corroborate the robustness and large size of the devaluation effects induced by response inhibition on palatable items, but challenge the assumption of a linear relationship between such effects and the actual consumption of the target items. PROTOCOL REGISTRATION: The stage 1 protocol for this Registered Report was accepted in principle on 30/03/2021. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/5ESMP .

A community-based feasibility randomized controlled study to test food-specific inhibitory control training in people with disinhibited eating during COVID-19 in Italy

PURPOSE

The aim of this study was to expand the evidence on the feasibility and impact of food-specific inhibitory control training in a community sample of people with disinhibited eating.

METHODS

Recruitment and data collection were conducted during the COVID-19 outbreak, in Italy. Ninety-four adult individuals with disinhibited eating were randomised to one of two conditions: App-based food-specific inhibitory control training or waiting list. Participants were assessed at baseline, end of intervention (2 weeks following baseline) and follow-up (one week later). The assessment measures included questionnaires about eating behaviour and mood.

RESULTS

Seventy-three percent of the sample reported a diagnosis of binge eating disorder, and 20.4% a diagnosis of bulimia nervosa. Retention rates were 77% and 86% for the food-specific inhibitory control training and the waiting list conditions, respectively. Almost half of the participants allocated to the training condition completed the "recommended" dose of training (i.e., 10 or more sessions). Those in the training condition reported lower levels of wanting for high-energy dense foods (p < 0.05), a trend for lower levels of perceived hunger (p = 0.07), and lower levels of depression (p < 0.05). Binge eating symptoms, disinhibition, wanting for high-energy dense foods, stress and anxiety were significantly lower at end of intervention, compared to baseline (p < .05).

CONCLUSION

Findings corroborated the feasibility of food-specific inhibitory control training, and its impact on high-energy dense foods liking. The study expands the evidence base for food-specific inhibitory control training by highlighting its impact on perceived hunger and depression. The mechanisms underlying these effects remain to be clarified.

LEVEL OF EVIDENCE

Level I, Evidence obtained from at least one properly designed randomized controlled trials; systematic reviews and meta-analyses; experimental studies.

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.

Food-Specific Inhibition Training for Food Devaluation: A Meta-Analysis

Theories have suggested that food-specific inhibition training could lead to food devaluation which, in turn, may help people to regulate their eating behavior. In this review, we have synthesized the current literature on this topic by conducting a meta-analysis of studies investigating the effects of food-specific inhibition training on food evaluation. We identified 24 studies-with 36 independent samples, 77 effect sizes, and 3032 participants-that met our inclusion criteria. Effect sizes were analyzed using the robust variance estimation in random effects meta-regression technique. The results indicate that food-specific inhibition training can lead to statistically significant reductions in food evaluation. More specifically, it was observed that the effects of training on participants' food evaluation differed according to the type of evaluation; food-specific inhibition training significantly decreased participants' explicit food evaluation, but not their implicit food evaluation. However, because most of the included studies focused on trained food items and short-term outcomes in normal-weight samples, more research is needed on the continuance of the training effects, as well as on the extent to which effects can be generalized to untrained food items or different populations (e.g., overweight or obese individuals).

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.