Persuasive technology for overcoming food cravings and improving snack choices

This research is partially supported by EPSRC Grant EP/G004560

Lunchocracy: Improving Eating Dynamics in the Workplace Using a Bot-Based Anonymous Voting System

Previous studies have shown that when individuals join groups for lunch, they tend to conform to the decision of the group. As result, people do not always have the chance to pick the food they wish for, which in turn may have negative consequences, such as not abiding to healthy diets. To address this problem, we created Lunchocracy, an anonymous decision support tool for lunch spots in a workplace based on feedback from a focus group with 7 participants. The tool implements a conversational skype-bot, Lunchbot, that allows users to express interest in joining lunch and to vote for diners to eat at. We deployed the tool for four weeks with 14 participants from the same university department. Post-interviews with 5 participants revealed an overall satisfaction with Lunchocracy, in particular due to it structuring the lunch decision-making and saving time. We discuss how the use of Lunchocracy can positively influence the group's eating dynamics

The Elaborated Intrusion Theory of Desire: A 10-year retrospective and implications for addiction treatments

Ten years after the publication of Elaborated Intrusion (EI) Theory, there is now substantial research into its key predictions. The distinction between intrusive thoughts, which are driven by automatic processes, and their elaboration, involving controlled processing, is well established. Desires for both addictive substances and other desired targets are typically marked by imagery, especially when they are intense. Attention training strategies such as body scanning reduce intrusive thoughts, while concurrent tasks that introduce competing sensory information interfere with elaboration, especially if they compete for the same limited-capacity working memory resources. EI Theory has spawned new assessment instruments that are performing strongly and offer the ability to more clearly delineate craving from correlated processes. It has also inspired new approaches to treatment. In particular, training people to use vivid sensory imagery for functional goals holds promise as an intervention for substance misuse, since it is likely to both sustain motivation and moderate craving

Derailing the streetcar named desire. Cognitive distractions reduce individual differences in cravings and unhealthy snacking in response to palatable food

People who are sensitive to food temptations are prone to weight gain and obesity in food-rich environments. Understanding the factors that drive their desire to eat is key to limiting their reactions to available food. This study tested whether individual differences in sensitivity to hedonic food cues are cognitively based and, accordingly, can be regulated by blocking cognitive resources. To this end, one lab study (study 1; N=91) and one field study (study 2; N=63) measured sensitivity to hedonic food cues using the Power of Food Scale (PFS; Lowe et al., 2009) and assessed participants’ appetitive responses to high-calorie food options. To test the role of cognitive elaboration of food cues, participants completed a menu-selection task to induce food cravings and then were free to elaborate those cravings (control group) or were blocked from doing so by cognitive distraction (solving puzzles, playing Tetris; experimental group). Compared to non-sensitive participants, sensitive participants displayed a greater attentional bias to high-calorie food (Study 1), reported stronger cravings (Study 2), and more often chose an unhealthy snack (Studies 1 & 2), but only when they had not been distracted. When distracted, all participants were similarly unresponsive to high-calorie food. This finding suggests that temptation can be effectively controlled by blocking people’s cognitive resources, even for people highly sensitive to hedonic food cues

Designing, delivering, and evaluating novel interventions to support dietary change for weight management

Background: Recent empirical research and theoretical models acknowledge that impulsive processes, can often undermine peoples’ attempts to lose weight despite currently available and effective support (Chapter 2). Aim: To develop, deliver, and evaluate an impulse management intervention to support weight loss in adults. Methods: A systematic review was conducted to identify available impulse management techniques for influencing eating behaviour (Chapter 3). Intervention Mapping was used to develop the intervention (Chapter 4) which drew on various sources including the findings from the systematic review, stakeholder consultations, existing guidance, and qualitative interviews. A two-arm randomised controlled feasibility trial (Chapter 5), with nested mixed-methods process evaluation and two cycles of intervention delivery and data collection (Chapter 6), was conducted. This assessed the feasibility and acceptability of, and informed refinements to, both the intervention and trial procedures in preparation for a full-scale effectiveness evaluation. Weight was measured as the proposed primary outcome for a full-scale trial at baseline, one-month, and three-months of follow-up, app usage data were collected at both follow-up time points, and semi-structured interviews were conducted at one-month with a subsample of intervention group participants only. Results: The systematic review critically appraised and synthesised evidence on 17 identified techniques which were categorised as Impulse-focused or Reflective techniques. Promising changes in eating behaviour and craving were found for the techniques of visuospatial loading, physical activity, and implementation intentions. Intervention Mapping resulted in development of a novel smartphone app-based intervention (ImpulsePal) aimed to reduce unhealthy snacking, overeating, and alcoholic and sugary drink consumption using impulse management techniques identified in the systematic review. Eighty-eight adults with a Body Mass Index of ≥25kg/m2 and wishing to lose weight, were recruited and randomised in a 2:1 ratio to use ImpulsePal (n=58) or to a waiting list control (n=30) group. Data were available for 74 participants (84%) at one-month and 67 (76%) at three months. Exploratory analyses suggest that the ImpulsePal group (n=43) lost 1.03kg (95% CI 0.33 to 1.74) more than controls (n=26) at one-month, and 1.01kg (95% CI -0.45 to 2.47) more at three months. Participants reported high satisfaction with the intervention and trial procedures. The process evaluation suggests that ImpulsePal and the impulse management techniques are feasible to deliver and acceptable to users. Interviews with twenty-two participants suggest that they valued having access to in-the-moment support, felt more aware of their own eating behaviour and influences on it, and felt an increased ability to resist temptations. Conclusions: This work has developed a novel, theory- and evidence-informed, person-centred app which showed potential to improve impulse management, promote healthier eating, and support weight loss. ImpulsePal is acceptable to overweight and obese adults who want to lose weight and is now ready for evaluation in a full-scale trial. The thesis discusses theoretical, methodological, and practical implications for the future development, evaluation, and implementation of digital behaviour change interventions.UEM

Working memory and food-related decision making

Dual-process theories argue that cognitive processes, and executive functions in particular, underpin controlled, goal-directed, decisions about food intake and choice. A considerable amount of research has been devoted to understanding the role of one executive function, inhibitory control, in appetite control. In addition, there has been interest in whether inhibitory control can be trained to improve dietary decisions. A systematic review and meta-analysis, however, casts doubt over the efficacy of training inhibitory control to change eating behaviour (Chapter 2). The importance of another executive function to eating behaviour, working memory, has been less well-studied. The aim of this thesis was to assess the role of working memory in food-related decision making in healthy volunteers and patients with type 2 diabetes. The results of Study 1 (Chapter 3) suggest that visuospatial working memory is important for decisions about the consumption of low energy dense foods and dieting success. The findings from Study 1 also provide support for the suggestion that dietary restraint has detrimental effects on central executive functioning. Study 2 (Chapters 4 and 5) found that working memory training can improve working memory and non-trained aspects of working memory in adults with type 2 diabetes. Transfer effects to eating behaviour were limited to those high in restraint (the higher the restraint the greater the reduction in saturated fat intake from pre-training to post-training). The results from Study 3 (Chapter 6) suggest that cognition (including one component of working memory) may be less important to food intake decisions in the context of other demographic, physical and psychological health factors. The importance of working memory to food intake decisions can be observed in controlled laboratory experiments. However, further research is needed to establish whether training working memory is a useful strategy to help bring about behaviour change to improve dietary choices

The effect of a mindfulness-based decentering strategy on chocolate craving

According to the elaborated-intrusion theory of desire, strategies that load visual working memory will reduce cravings. According to the grounded cognition theory of desire, cravings will be reduced with mindfulness-based decentering strategies that encourage individuals to see their thoughts as thoughts. However, decentering strategies also tend to load visual working memory making it difficult to test the latter prediction. This study addressed this issue by matching visualization across decentering and guided imagery tasks. Male and female participants (n = 101) underwent a chocolate craving induction before listening to a 4-min audio recording that guided them to (a) decenter from their thoughts and feelings, (b) engage in visualization, or (c) let their mind wander. Participants reported on chocolate craving before and after the craving induction and following the 4-min recording. They also provided retrospective reports of craving during the recording, reported on the extent to which they had adhered to the audio instructions and briefly indicated what they had been thinking about during the recording. Results showed a significant reduction in cravings to baseline following the recording across all three conditions (p < .001), but no significant differences between conditions or in the retrospective reports of craving. There was some evidence to suggest that participants in the mind wandering condition had been thinking about alternate goals, which may have inhibited thoughts about chocolate and been just as effective at reducing craving as the imagery and decentering strategies. Exploratory analyses showed a trend toward decentering being more effective than imagery where participants reported higher task adherence throughout the 4 min (p = .067). This raises the possibility that decentering effects may be improved with better strategy adherence, which might be achieved through practice or increased motivation

Combining Marketing and Behavioral Research to Develop and Evaluate a Healthy Vending Intervention on a College Campus

Objective: To utilize a comprehensive approach for developing and evaluating a healthy vending intervention introducing a healthy bean snack product in campus vending machines to positively impact factors related to college students’ dietary behavior. Methods: The full project included five sequential phases to inform, develop, and implement a vending intervention that introduced a specific healthful dried bean snack product in campus vending machines. First, we conducted multiple-methods cognitive interviews with 60 college student vending users to select the most liked, preferred, and influential product, price, and promotion for the intervention. Next, we used observations and intercept surveys to describe and compare vending contents, sales, and consumer characteristics. We then used intercept interviews to compare awareness, attitudes, and purchases of the intervention product with and without a point-of-purchase promotion. Finally, we implemented the determined intervention and compared changes in perceived healthfulness of campus vending machines and environmental, personal, and behavioral factors related to the intervention product from pre- to post-intervention and between vending and non-vending users. Demographics and vending usage measures were assessed and compared throughout the project. Results: The five phases included a total of 255 student participants, with a majority being female (63%) and white (82%). Approximately 50% of participants used vending machines at least once per month with the most common reasons for purchasing vending items being hunger, lack of time, and convenience and reasons for choice being price, health, and taste. We also found a significant relationship between higher frequencies of vending usage and higher weight status. The intervention strategy only included the product, due to no significant differences in intervention product awareness, attitudes, or purchase with the promotion. Intervention impact overall was low with only 5 participants (11%) aware of the intervention product. Vending users significantly increased their perceived healthfulness of vending from pre- to post-intervention, with a significantly greater increase compared to non-vending users, after controlling for diet. Conclusion: This project provides an example of how combining marketing and behavioral research and principles can inform the comprehensive development and measurement of healthy vending interventions on college campuses

Effects of working memory on naturally occurring cravings

This is the author accepted manuscriptElaborated Intrusion (EI) theory posits a key role for visuospatial working memory (WM) in craving. In line with the predictions of EI theory, several studies have found that WM and craving show mutually interfering effects - for example, performance of visuospatial WM tasks has been found to attenuate naturally occurring cravings. However, the extent to which these effects are driven specifically by visuospatial processing remains unclear. We conducted two experiments to investigate the effects of WM on naturally occurring cravings in more detail. In experiment 1, we examined whether such effects are driven specifically by visuospatial WM processes or can also be induced by a verbal WM task. Subjective craving ratings were attenuated equally by performance of visuospatial and verbal WM tasks, suggesting that craving is not dependent specifically on visuospatial processing. In experiment 2, we examined whether effects of visuospatial WM on craving could be driven by simple distraction. Naturally occurring cravings were attenuated in a control condition with minimal WM demands (watching a video). However, the magnitude of attenuation was significantly greater in a visuospatial WM condition. Taken together, these findings highlight a key role for WM in the attenuation of naturally occurring craving, but do not support the hypothesis that such effects are dependent specifically on visuospatial processing