Enhancing inhibitory learning to reduce overeating: Design and rationale of a cue exposure therapy trial in overweight and obese women

Snacking and anxiety during the coronavirus disease (COVID-19) pandemic: A prospective cohort study

Anxiety and snacking increased during the initial coronavirus disease 2019 (COVID-19) lockdowns, but it remains unknown whether this change in snacking persisted and if it related to anxiety levels. We used prospective data to examine changes in snacking frequency from t1 (eased restrictions in England in May-June 2020) to t2 (national lockdown in December 2020-March 2021), the association of anxiety (assessed by the Generalised Anxiety Disorder-7 questionnaire at t1) with the snacking change, and the mediating and moderating effects of disinhibition and flexible restraint (assessed by the Three Factor Eating Questionnaire in 2016-17). Analyses including 2128 adults (mean age 28.4 y) residing in England from the Avon Longitudinal Study of Parents and Children showed that snacking frequency increased over time (mean change 1.23 (95% CI 0.81, 1.65) snacks/wk). Linear regressions of snacking adjusted for sociodemographic covariates showed that having clinical levels of generalised anxiety at t1, versus not, was associated with 1.22 (95% CI 0.07, 2.37) more snacks/wk at t2. Disinhibition partially mediated the association between Generalised Anxiety Disorder and snacking (β_indirect = 0.15, 95% CI 0.01, 0.32), while there was no evidence that flexible restraint moderated the association (β = 0.05, 95% CI -0.57, 0.66). Our longitudinal findings highlight a detrimental anxiety-snacking association partly operating via disinhibition, suggesting future research could target mitigating anxiety and disinhibited eating behaviours to benefit diet-related outcomes following the pandemic.

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.

Neural Correlates of Food Cue Exposure Intervention for Obesity: A Case-Series Approach

Background

People with overweight have stronger reactivity (e.g., subjective craving) to food cues than lean people, and this reactivity is positively associated with food intake. Cue reactivity is a learned response that can be reduced with food cue exposure therapy.

Objectives

It was hypothesized that participants after food cue exposure therapy would show reduced neural activity in brain regions related to food cue reactivity and increased neural activity in brain regions related to inhibitory-control as compared to participants receiving a control lifestyle intervention.

Method

Neural activity of 10 women with overweight (BMI ≥ 27 kg/m²) in response to individually tailored visually presented palatable high-caloric food stimuli was examined before vs. after a cue exposure intervention (n = 5) or a control lifestyle (n = 5) intervention. Data were analyzed case-by-case.

Results

Neural responses to food stimuli were reduced in food-cue-reactivity-related brain regions after the lifestyle intervention in most participants, and generally not after the cue exposure therapy. Moreover, cue exposure did not lead to increased activity in inhibitory-control-related brain regions. However, decreased neural activity after cue exposure was found in most participants in the lateral occipital complex (LOC), which suggests a decreased visual salience of high-caloric food stimuli.

Conclusion

Receiving a cue exposure therapy did not lead to expected neural responses. As cue exposure relies on inhibitory learning mechanisms, differences in contexts (e.g., environments and food types) between the intervention setting and the scanning sessions may explain the general lack of effect of cue-exposure on neural activity.

Cognitive Restructuring vs. Defusion: Impact on craving, healthy and unhealthy food intake

Coping with food cravings is crucial for weight management. Individuals tend to use avoidance strategies to resist food cravings and prevent overeating, but such strategies may not result in the benefits sought. This study compared the effects of two cognitive techniques (Restructuring vs. Defusion) for dealing with food cravings in terms of their impact on healthy vs. unhealthy eating behavior (i.e., consumption of chocolate and/or carrots following the intervention). Sixty-five participants (M_age = 19.65 years) received either a 30-minute face-to-face instruction on cognitive restructuring (CR) or cognitive defusion (CD) along with 15 min of practice, or 45 min of obesity education and discussion (control). To examine craving and eating choices following the intervention, participants received bags of chocolate and carrots and were asked to carry these with them at all times over the next week, exchanging the bags every 2 days. Participants in the CD group ate fewer chocolates (M = 11.74) compared to CR (M = 17.06) and Control groups (M = 29.18) during the experimental week. The groups did not differ in number of carrot pieces eaten, though the CD group ate more carrots than chocolates. CD resulted in fewer self-reported cravings compared to CR and CO groups. At a final taste test, both CD and CR groups ate significantly fewer chocolates compared to the CO group. CD appears to be an effective technique in managing food craving and to present some advantages over CR.

The effects of a gamified approach avoidance training and verbal suggestions on food outcomes

There is initial support for the effectiveness of approach-avoidance trainings in altering food-related health behaviors. Furthermore, outcome expectancies induced by verbal suggestions might optimize the effectiveness of these interventions, as shown in placebo research. The present study investigated the effectiveness of a gamified approach-avoidance training on food-related outcomes and whether verbal suggestions could strengthen those effects. A total of 120 participants were randomly assigned to 1 of 4 conditions: serious gaming only, verbal suggestions only, serious gaming combined with verbal suggestions, or a gaming control condition. Virtual food preference and food choice were assessed with a food choice task, with pairs differing in healthiness or in healthiness and attractiveness. Implicit food preference was assessed with an Implicit Association Test and food intake with a bogus taste test. Participants in both serious gaming conditions made healthier food choices for pairs differing in healthiness and attractiveness and had healthier implicit food preferences compared to gaming control. No effects were found on food intake. These findings provide the first preliminary support for the effects of a gamified approach-avoidance training on virtual food choice and implicit food preference. Future studies should further elucidate these effects, also in other health domains such as physical activity.

The Impact of Self-Reported Impulsivity on the Course of Weight Is Mediated by Disinhibited Eating

This study investigates the impact of impulsivity and the mediating role of disinhibited eating behaviour (DEB) on weight and weight trajectories in a large data set including obese non-treatment seeking individuals (obese control, n = 138) and obese individuals who were either receiving a conventional treatment program (n = 227) or bariatric surgery (n = 123). Data was assessed one, 4 and 9 years after baseline including self-reports for impulsivity and DEB. Results suggest a significant association between impulsivity and body mass index, which is partially mediated by DEB. Longitudinally, the influence of impulsivity on the course of weight after 9 years was fully mediated by DEB in obese control but not in the treatment groups. The results indicate an interplay between impulsivity and DEB with respect to obesity. Further research is needed to clarify how the mediation works and when it exerts its effect, in order to identify those that might profit from a specific (impulsivity-reducing) training. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Altered appetitive conditioning in overweight and obese women

Overweight and obese individuals show increased psychological and physiological reactivity to food cues and many of them have difficulties in achieving long-term weight loss. The current study tests whether abnormalities in the learning and extinction of appetitive responses to food cues might be responsible for this. Overweight/obese and healthy weight women completed a differential appetitive conditioning task using food as rewards, while eating expectancies, eating desires, conditioned stimulus evaluations, salivation, and electrodermal responses were assessed during an acquisition and extinction phase. Results suggested reduced discriminative conditioning in the overweight/obese group, as reflected by a worse acquisition of differential eating desires and no successful acquisition of differential evaluative responses. Some evidence was also found for impaired contingency learning in overweight and obese individuals. No group differences in conditioned salivation and skin conductance responses were found and no compelling evidence for differences in extinction was found as well. In sum, the current findings indicate that overweight and obesity may be characterized by reduced appetitive conditioning. It is suggested that this could be causally related to overeating via stronger context conditioning or a tendency towards overgeneralization in overweight and obese individuals.