Title: An investigation to examine the feasibility of progressing to a double blind randomised controlled trial to investigate whether a novel intervention targeting the automatic processes involved in binge eating is of benefit for people with bulimia nervosa or binge eating disorder
Funder: Department of Health and Social Care

Abstract: Background: Bulimia Nervosa (BN) and Binge Eating Disorder (BED) begin in young adulthood and can have a protracted course (32% remain symptomatic after 22 years)2. The impact on health, quality of life and vocational and developmental functioning is large4. Current treatments are disappointing with a recovery rate of only 40%2, 5. Improving treatments by profiting from the greater understanding of the mechanisms that underpin the disorder offers exciting developments. Anomalies in inhibitory and learning processes are thought to subserve binge-eating6-10. Impairments in inhibitory control towards food and weight stimuli have been found in people with BN (moderate effect size in meta-analysis)11 and in people with BED12, 13. It follows that improving food-specific inhibitory control and reducing unhelpful habitual eating disorder behaviours in BN and BED may be of benefit14. In pre-clinical single session studies that target automatic processes, such as heightened approach to food (with deficient inhibition) and unhelpful habitual behaviours (i.e. behaviours primed by environmental cues rather than goals and intentions) have been shown to change eating behaviours15. Preclinical studies using 4 weeks of food specific inhibition training changed the balance between high and low calorie food consumption and led to weight loss3,16,17. A recent pilot study of food inhibition training (targeting eye gaze) reduced binge eating in BED18. In a proof of concept study of food specific inhibition in people with BN and BED, a single session of training to inhibit the motor approach to binge foods reduced consumption (effect size[ES]=0 .23) in a subsequent laboratory test (Turton et al., submitted). Patients found these interventions to improve inhibition acceptable. Changing unhelpful eating attitudes and behaviours takes time, and therefore in this project we will deliver training over four weeks. Question addressed: Is it feasible to undertake a double blind randomised controlled trial to examine whether a novel treatment module, including training to inhibit approach to binge foods, and guided goal-planning from a mentor to interrupt unhelpful habitual eating disorder behaviours, can enhance treatment outcomes for people with BN and BED when added to treatment as usual (TAU)? Plan: This study is designed as a prototype to test the study parameters involved in the full scale study. Participants: 80 people with BN or BED receiving outpatient treatment. Intervention: Individuals are randomized to one of two conditions. In one condition, participants will receive food-related go/no-go inhibition training and food-specific guided goal planning (using an implementation intention if-then planning approach) with the aim of reducing binge eating frequency. For instance, &quot;if I feel the urge to binge eat, then I will use a distraction technique&quot;. Participants in this condition will receive telephone or email guidance from a mentor. In the other condition, participants will receive non-food-related go/no-go inhibition training and general goal planning (not specifically related to eating) alongside the guidance from a mentor. Outcomes: Fidelity: Frequency of use of materials. Primary outcome: binge frequency at 4 and 8 weeks as measured by a structured questionnaire (Eating Disorder Examination Questionnaire, EDE-Q). Additional outcomes: Body Mass Index (BMI), eating disorders symptoms, food craving, and health-related quality of life (4 and 8 weeks), food liking and wanting (4 weeks) and calorie consumption during a taste test (8 weeks). Summary of patient benefits: This novel intervention includes the use of digital technology to target key risk and maintaining factors for binge eating disorder and bulimia nervosa. If, as anticipated, the intervention reduces binge eating frequency, it could be easily added as subsidiary module to standard treatment for eating disorders. This would provide an upgrade with opportunities for wide reach and easy dissemination.

Lay abstract: This project aims to provide more effective and accessible treatment for people with bulimia nervosa and binge eating disorder. We are testing whether a new food-specific intervention using a computerised training program and support in the form of goal planning has benefits over a non-food-specific intervention. Background: The success rate of treatment for binge eating is below 40%, with over 30% of patients experiencing symptoms 22 years after their illness begins (11). Neuroscience research shows that binge eating is caused by weak control over impulses to eat and strong habits. Habits are learned behaviours, and can be reversed through repeated training. We have developed a computer game that trains people to repeatedly stop (pressing keys) to binge-foods. This game has reduced overeating habits in the general population (4) and reduced consumption of binge-foods among people with eating disorders in a laboratory setting (12), with participants expressing its potential as a treatment. Other research shows that planning personalized goals can help improve self-control (12). The intervention in this project includes daily computerised training at home, a food diary, and goal planning with a mentor. Participants: We will recruit people with bulimia nervosa and binge eating from clinical and community settings. Study plan: Participants will be randomly divided into two groups. One group will engage in food-specific computerised training and goal planning with a mentor over 4 weeks, while the other group will engage in non-food-related computerised training and goal planning with a mentor over 4 weeks. Outcome: We will examine the acceptability of the intervention, such as participants likelihood of taking part and completing the full intervention without any harmful influence on their safety and well-being. We will also measure standard clinical outcomes such as binge frequency, level of compensatory behaviours (vomiting, exercise), and wellbeing.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL
Health categories: MENTAL HEALTH