Computer Games for Obesity and Diabetes Prevention: Interfacing Behavior Change Techniques to Game Elements

Written by Brian Mayrsohn, MS

Research Assistants: William Butler, Christopher Gates, Georges Khalil MPH

FIRE Mentor: David Metcalf, PhD.

University of Central Florida College of Medicine

2. AbstractWith the increasing burden of chronic diseases such as obesity and diabetes, there is a strong need for a low cost solution that can be scaled for the masses. While grass-roots style campaigns may have many obstacles, especially with respect to scalability and manpower. Therefore, leveraging Internet to disseminate games for health may prove to be a cost-effective and perhaps more efficacious alternative. Games such as Diab, Zamzee, among other mobile and Wii games have shown to have a statistically significant impact on health They can improve the delivery of care across the healthcare continuum while also increasing reach and patient buy in. Successful health games are based on theoretical frameworks and of course fun, which requires the successful implementation of game elements. However, terminology used by researchers is either not synchronous or lacking making it difficult for others to refer to a consistent approach. The purpose of this study is to bridge the gap between the designers and the behavioral scientists to enable them to create games based on behavior change game-elements (BCGEE) that are optimally designed to be fun and engaging but also transformative. The aim of this study is to create a tool to assist researchers and game designers in the identification of BCGEE necessary to create more efficacious games that can create behavioral changes. In depth interview are also crucial pieces in helping to construct at tool such as this one rather than strict theory itself. This tool lays the cornerstone in an otherwise dispersive domain.

3. Lay Abstract Games for health have the potential to change the way patients engage nutrition and physical fitness, and hopefully result in healthy behavior. With that said, games for health is a relatively new field and like any new discipline, there are growing pains. There is not a common terminology that all within the field use, and as a result, there is no universal standard at which to build the industry on. The aim of this study is to create a tool that health game developers can use to identify the correct terms and examples to make a successful behavior change game.

4. Background:

With the increasing burden of chronic diseases such as obesity and diabetes, there is a strong need for a low cost solution that can be scaled for the masses. Traditionally, behavioral change interventions aimed at changing physical activity and eating patterns range from individual-level to community-level1and demonstrate small to moderate effects on weight loss2. Additionally, skill level, time commitment, and expenses vary among health professionals, which, combined with the lack of program effectiveness, reach, and sustainability may account for the lack of substantial impact1. However, its important to note that in person treatment sessions are more effective than mass media campaigns3. While grass-roots style campaigns may have many obstacles, especially with respect to scalability and manpower. Therefore, leveraging Internet to disseminate games for health may prove to be a cost-effective and perhaps more efficacious alternative if combined with in person activities. Once a game finishes production, it can then be scaled at a relatively cheap cost, especially when compared to traditional person-to-person interventions.In 2011, Pew Internet found that 80% of internet users have looked up health related information at one point4. Already, 18% of internet users go online to look for others with similar health concerns, and studies show that people with chronic diseases are even more likely to participate5. Noting the internets technological powers and social attraction, the use of online-internet-based behavior intervention programs will prove to be an effective strategy to target obesity and diabetes predisposed populations. Over the last decade, interventions delivered over the internet that focus on physical activity1,2,610 and diet2,9,1113 have become more prevalent. Games such as Diab, Zamzee, among other mobile and Wii games have shown to have a statistically significant impact on anthropometric and physiological measures and health behaviors14,15. They can improve the delivery of care across the healthcare continuum while also increasing reach and patient buy in. Ultimately, this can increase patient behavior change, which directly impacts their health and outcomes. While each game employs game elements differently, the theoretical basis for which they are derived from can be narrowed down to a select few, including but not limited to Social Cognitive Theory (SCT), Self-determination Theory (SDT), and Transport Theory (TT)16. Furthermore, these psychological theories have been successfully used for decades in various types of interventions and experiments and by using the evidence amassed over the last century, researchers can embed these frameworks within games for health 1719. Games act as a new medium for these techniques to be applied. Internet-based games offer several advantages than their traditional counterparts because not only do they offer reach, availability, and opportunities20for interactive approaches10, but also because information and messages can be tailored to participants for personalize the experience21. Furthermore, games provide a way for users to anonymously seek out sensitive health information not to mention make it fun and engaging8. Unlike previous generations, gamers today carry their handheld game consoles everywhere they go and with over 183 million gamers logging in on average at least thirteen hours a week in the US alone, games could be a logical approach to engage the masses without disrupting their normal lifestyle22. The relevance of entertainment education (E-E) in games is tremendous given its already overwhelming potential and previous applications23. Similar to television, games in particular have the potential to be effective vehicles for behavior change because they weave storylines, and characters with behavior change procedures including modeling, skill development, self-regulatory behaviors, reward, and immediate feedback9. E&E has traditionally been used in television, but because the Internet requires more involvement from its users [than television], users in turn may give it greater attention and credence. For instance both games and movies provide a vehicle for story immersion, however games allow for the individual to interact through an avatar within the game environment12,24,25.The scientific study of behavioral change plays an essential role in video games that promote healthier lifestyles, although further research is warranted2,26. Particularly promising are those video game interventions which are rooted in behavioral theory and applied psychological interventions16. The results of these analyses are not surprising because adopting new habits requires overcoming difficult psychological obstacles and numerous behavioral changes. Despite this, behavioral science attempts to explain the complex ways in which individuals change and has found video games to be particularly effective as they engage the player emotionally, cognitively, and behaviorally,however, knowing how to interface behavior change techniques (BCTs) with game-elements is still unclear2,9. While each of these BCTs are unique and carry varying degrees of importance, the game architects salient objective is to systematically combine them in such a way that they complement one another to create an unobtrusive fun game. Without the fun factor, which also requires carefully applied game elements and narrative, a health game will not be effective.The purpose of this study is to bridge the gap between the designers and developers and the behavioral scientists to enable them to create games based on behavior change game-elements (BCGEE) that are optimally designed to be fun and engaging but also transformative. The aim of this tool is to assist researchers, game developers, and game designers in the identification of BCGEE necessary to create more efficacious games that can create behavioral changes.

5.0 Methods:

Overview:Based on the categorization of Michie and colleagues we operationalized these concepts and identified five categories to be considered for inclusion in the tool: Theory (a set of interrelated concepts, definitions, and propositions that systematically explain or predict events or situations)16. Theory-relevant construct is a construct within atheory broken into a unit or element by which psychological theories are based)16. A BCT is a strategy to change behavior through a theory or construct. Game Elements (GE) include game mechanics, game aesthetics, and game thinking that goes into creating a fun game. BCGEE is a Game element example (GEE) that has been methodically matched to a BCT through a GE definition intermediate.

Review of behavioral change techniques and the relevant theoretical constructs.

An initial list of BCTs was amassed using Michie and colleagues 2013 taxonomy that identified 93 BCTs. Their study previously assigned all theory-relevant constructs to their respective theory and therefore the foundation of this tool is their taxonomy and therefore those were also the theories incorporated into the prototype. In the context of chronic diseases and physical activity, they include SCT, TT, SDT, operant and classical conditioning, transformative theory,theory of planned behavior, and the inoculation theory. These theories were selected because researchers continuously apply them and study them and found most often in the literature. Many other theories have not yet been applied or studied, and therefore were excluded from the study.

Review of game elements.

Secondly, games, GEs, and GEEs were identified as a result of a systematic review. A web search was conducted using PubMed and Google Scholar applying combinations of the following keywords: games for health, game and behavior change techniques, games for change, obesity, diabetes, health, fitness, mobile devices, mhealth. The studies that were chosen for incorporation into the tool had demonstrated sufficient evidence that their game applied an acceptable level of behavior science and that there was a significant positive change in health behavior, knowledge, self-efficacy, or confidence. Using several sources including books and research journal articles, the most succinct, accurate definitions were utilized and iterated upon. The definitions of GEs will be referred to from here on out as definition database which is the basis for our study, if a resource labeled a GE within their game that did not meet our criterion, we relabeled their GE based on our definition database. 65 abstracts, 20 full length journal articles, select sections from five books were read and a course taught through Coursera, an online educational platform, by Kevin Warbach a Wharton School of Business professor at University of Pennsylvania, was attended. Such a literature review allowed us to identify GEs described by authors in the literature. To the best of our ability, we then formed BCGEE by pairing GE with BCTs. As a result, BCTs interface theory-based constructs and GE. Following the completion of the prototype, in depth conversations with one behavior scientist and two behavior change game design experts were conducted. While the discussions were critical to validating the language used in the tool, they also served to gather feedback from stakeholders who are the target audience for the application of this tool. In other words, these conversations were important to the construction of this tool because it is more than a theoretical application of psychology and game theories but rather a practical one. They were each asked a series of questions including: do you think that the Game Elements match the psychology behavior change technique. Do you find that these definitions are helpful? How do you think this tool could be improved?

Creating the Tool:First we located the most common studied theoretical frameworks in the games for health literature including SCT, SDT, TT, ELM, BIT15. Using the psychology literature, we then identified the theoretical constructs associated with each theory1719,27,28. Once we created a table of approximately seven overarching theories, we identified three to five constructs associated with each theory. BCTs are theory-derived methods for changing one or several constructs of a persons behavior. Then, we matched BCTs with specific constructs to focus on specific elements that support each theory, which could be applied through game mechanics.Through review of meta-analysis research and similar research, we were able to pair BCTs to constructs as well as GEs in ways that were logical and supported29,30.Next, using the definition database created from the literature, we matched corresponding BCT definitions to create a Definition Pair.After the connections were made, the games for health literature was used to locate examples of the GEs used in practice. It was originally thought, that by matching the GE definitions to the examples found within the literature, we would therefore have matched the GE example not only to the BCT, but also to a theory. Games for health is a relatively new field composed of many disciplines. As such the operational definitions vary among disciplines and even between scholars. Many theories that independent researchers reference as the driving force behind their interventions success seemed to overlap, however the theories were either applied differently, or the terminology used was not synchronous31,32. This was the case in both the games for health field as well as the behavioral psychology field6,15. With that said, by focusing on the most discussed and understood BCTs in games for health research, we were able to retain accuracy in our connections rather than speculate on less researched concepts12,15,32.In the game, Escape from Diab, the authors used motivation statements in accordance with SDT, because they can help a player see the relevance a behavior can have on something that carries importance to his or her life. They sought to elicit this connection using value reason statements and internal motivation in the riddle example, however there was no GE mentioned or defined. We therefore used our definition database and matched it to riddles, which is defined as a mental challenge with at least one correct solution state that the player must find33. Like this paper, there were several othersalso written by reknown experts in this fieldthat utilized an equivalent degree of behavioral science in the design identified specific GEs and theoretical frameworks within their research, which formed the backbone of this tool. Their clear and thorough explanation of the application of theoretical frameworks assisted tremendously in pairing BCTs to GE definitions. However, after consulting with experts in the games for health field, it was apparent that the theories and constructs were not a necessary component of the tool, and should not be the foundation by which it is built. Therefore, the GEEs became the starting point from which the associations were made. The GE definitions were then paired to the GEE. The term the researchers assigned to the GE was taken into consideration as the proper term to be used, but often, the term used to describe the GE did not fit any definitions within the GE definition database and therefore a more appropriate definition was assigned. This was the approach taken for every GE example used. Further complicating matters, some papers utilized GEs without explicitly identifying them6,15, therefore the GE definitions guided us in further identifying GEE. This is a similar approach used in The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques: building an international consensus for the reporting of behavior change interventions.In an effort to prevent this study from having to establish two sets of new definitions for two fieldsbehavioral science and games for healththe BCTs identified previously identified were discarded, and only employed Michie and colleagues' taxonomy, which consisted of 93 BCTs with matching definitions and examples that have already undergone rigorous evaluation by a large team of experts. The next step linked the GE definition with a BCT definition. Once a definition pair was made, we presumed the BCT example from the taxonomy should in fact match the GEE, but then further analyzed the connections to further to confirm or contradict our hypothesis. For instance, in the RightWay Caf, positive attitudes toward healthy eating are promoted by providing positive feedback and rewarding points to players when they choose healthy food. This GEE was termed a reward, and defined as: the player receives something perceived as positive, or is relieved of a negative effect, for completing goals in the game." This GE definition matches nearly perfectly with Non-specific incentive, which is defined as: Inform that a reward will be delivered if and only if there has been effort and/or progress in performing the behavior (includes Positive reinforcement). On occasion, there was not an obvious match. In that case, the GEE was compared directly to a BCT, which is the procedure that occurs following a successful definition pair being matched up. In several instances, the definition pair required two or more BCTs to properly match the GE definition because there was no obvious choice. Furthermore, despite a relatively accurate fit between the definition pair, the GEE and the BCT did not match and we therefore the definition would undergo reassessment. It is important to note that the 2013 taxonomy does not include game for health interventions, or for that matter, interventions that utilized technology. This added to the burden of attempting to interface the two disciplines.

6.0 Results:

The original tool created has been iterated considerably since it was initially conceptualized. Conversing with the end users (the behavioral scientist and the game designer experts) helped to shape the need, purpose, and application of the tool. By working with behavioral scientists before game designers, the psychological basis by which the tool was founded was strengthened. By working closely with game designers and developers, additional user friendly components were added. Initially, the tool was composed of behavioral theories, constructs derived from those theories, BCTs, and game elements, and the game element examples. After speaking with interviewee one, it was apparent that including the theories and constructs would be unnecessary for game developer because it is beyond the scope of their knowledge, not to mention confusing. One of the behavior scientists stressed the importance of switching the BCT reference from the 2008 taxonomy to the 2013 version. This transition required a reworking of the connections between many of the GEEs because many of Michie et al.s termsespecially the more generalwere reworked to be more specific which left the definition pairings inaccurate. Additionally, the 2013 taxonomy added many new BCTs. For example, the GE Feedback was originally paired to the BCT General Encouragement, however General Encouragement was not included in the 2013 taxonomy. Therefore pairing the Feedback GE with a BCT definition became more complicated.

BCGEE NameBCGEE Definition

FeedbackGames provide information feedback. Feedback in learning or playing games is designed to evoke the correct behavior, thoughts, or actions. Games provide information upon which the player can act. The information feedback is designed to indicate the degree of rightness or wrongness of a response, action, or activity. Feedback immediately informs the learner if he or she did the right thing, the wrong thing, or somewhere in the middle but doesnt tell the learner how to correct the action.

BCT NameBCT Definition

General Encouragement (2008 BCT) Praising or rewarding the person for effort or performance without this being contingent on specified behaviors or standards of performance

Feedback on behavior [2.2][2.2] Monitor and provide informative or evaluative feedback on performance of the behavior (e.g. form, frequency, duration, intensity).

Feedback on outcome(s) of behavior [2.7[2.7] Monitor and provide feedback on the outcome of performance of the behavior

Non-Specific Reward [10.3][10.3] Arrange delivery of a reward if and only if there has been effort and/or progress in performing the behavior (includes Positive reinforcement)

Table 1.

As a result, no one BCT definition matched precisely. By using the BCGEE to guide the definition pairing process, it was concluded that by combining feedback on behavior, feedback on outcome(s) of behavior, and non-specific reward, a definition was pair was created as shown in Table 1. It was also expressed by the same interviewee that the GEEs have to be easier to understand, which led to a reworking of the GEEs into more concise, plain worded explanations as shown in Table 2.

Old GEOld BCGEE

QuestBACKGROUND: 'Fitter Critters!,' developed by Megazoid Games (Collegeville, PA), is an online videogame intended for use in schools for children 812 years old...In the game, the player is responsible for the health of a virtual pet (Critter). The game aims to increase healthy eating and activity knowledge and improve health behaviors by having children complete quests to learn how food and activity choices influence their Critters behavior and health." QUESTS: "The game had 17 quests to enhance motivation for game playing, help master the game basics (e.g., visit the grocer, purchase foods), and increase nutrition and activity knowledge." KNOWELDGE: "By choosing healthy foods without surpassing the fat, sugar, and caloric allotment, the Critter becomes healthier, wins more sport games, earns more money, and is sick less. Having the Critter be physically active improves its health and reduces its body fat. Critters who frequently exceed the fat, sugar, or calorie limits become unhealthy, earn less money, are more likely to be sick, and perform poorly in sport games. These Critters reject healthy choices, such that poor choices reinforce one another; this can only be reversed via consistent healthy choices."

New GENew BCGEE

Quest"Fitter Critters had 17 quests to enhance motivation for game playing, help master the game instructions (e.g., visit the grocer, purchase foods), and increase nutrition and activity knowledge (e.g., ll healthy bars without lling unhealthy bars). This instructs the users on how to perform specific behaviors (for example, identifying fruits and nonfruits) and gives feedback on health consequences."

Table 2.

It was our goal to provide the end user with as much information as possible regarding the context in which that GE was applied. We therefore included many quotes from the text in an attempt to recreate the setting by which the author intended. A suggestion from game design expert number two was to create a website where clips of pictures of the GE actually being applied would be more helpful, which will be a project for the future.When speaking with the game design expert number one, it was clear that he could not see the application of the GEE for an intervention, and he asked for examples of the BCT to be included to provide a point of reference for the GEEs. The 2013 taxonomy has examples associated with each BCT, so in an effort to be consistent and to maintain the taxonomy as the foundation for this tool, the examples were incorporated verbatim. An important point that should be emphasized from the interviewees was that some GE are clearly more important than others and should be leveraged as often as possible when it makes sense. One of the interviewees emphasized the importance of the multiplayer feature and explained that it was very powerful and can have dramatic impacts on the user if social pressures are present. By collaborating with several behavioral scientists and game designers, common ground outside of the literature was found. In depth interview are also crucial pieces in helping to construct at tool such as this one rather than strict theory itself. This tool lays the cornerstone in an otherwise dispersive domain. See Figure 1 for the tool.

7.0 Discussion:

After reviewing the games for health literature, it is clear that there is a surge in publications and activity, but it is evident that the field is in its infancy and the games theoretical integration needs improvement34. In the past video games have traditionally been placed in the home35 and health games directed at preventing and treating childhood obesity were outside the home36. However, the wide availability of mobile technology including smart phones and tablet devices is extremely pervasive and has led to the infiltration of health games throughout all aspects of life37. Interestingly, the commercial games implemented in arcades are exergames and exergaming stations, whereas those from researchers focused on nutritional behaviors34. The gaming industrys preference towards PA games seems logical given the ease at integrating entertainment with PA rather than nutritional behavior components. Lu et al. and Mayrsohn and Khalil emphasize the importance and of drawing insights from successful commercial games to create innovative psychological and behavioral theoretical frames34,37. It was therefore the aim of this study to highlight successful games that were effective in positive health behavior change outcomes to identify useful GE for designers to draw inspiration from. While this tool could never substitute for collaboration between behavioral scientists and game designers, it can however serve as a guide for game designers who do not have access to researchers and vice versa. Combined with an off the shelf game, it can empower researchers with a list of GEEs that can serve as a starting point for producing behavior change games and provide research for game developers on how to incorporate BCTs into their commercial games. This tool can be used in several ways. Depending on which field you come from dictates how one would apply it. Behavioral scientists will read the tool from left to right, whereas game designers will right the tool from right to left. However, more interviews will be required to determine the full extent to which this tool can be applied. To date, interviews have focused mainly around the tools accuracy, and not how one would create a game from its contents. Some limitations of this tool were the selectivity of the games chosen for incorporation. The games cater to a population from ages five to twelve; therefore the scientific evidence will only support using the BCGEE for those ages. However, the basic principles behind the connections is still accurate, and therefore a game designer only has to tweak the GEE to better match the population being targeted.

Theory Applied to Games

According to SCT, it is extremely important to increase an individuals self-efficacy, because unless he feels that he can produce the desired effects by his actions, there is little incentive to act out the new behavior12. By linking theory to BCT to GEEs, researchers will be sure they are included a GE with a scientific evidence for improving self-efficacy and thus achieving the goals of the game. Escape from Diab is an excellent example of the proper approach for applying theories. In figure 2, the blue highlighted BCTs and GEs represent the associations identified from this game. They have an excellent explanations and a table of how their BCTs and GEs, which they call change procedures, and theoretical constructs, which they call mediators relate to underlying psychological theories. Similarly, a nutrition promotion game called Rightway Caf does an outstanding job in weaving theoretical frameworks into the fabric of the game, which included the health belief model, SCT, and theory of reasoned action. The game elements were interactive tailoring, role-playing, the element of fun, and narrative to create a safe environment for users to practice behavioral rehearsal12. Whereas many health campaigns focus on the unhealthy results of living an unhealthy lifestyle, this game emphasizes the positive results living healthy can bring such as stronger muscles, better hair, and better skin12. Probably the most important point one can draw from this example is that Rightway Caf, like the other papers chosen for this review, uses a combination of GEs for their games. This is not a random combination of GE lumped together, but rather a strategically chosen set that complement one another. Application of different GE is critical to the success of a game. For example, in-app reminders can be an excellent way to remind the user to perform a task, but they can also become annoying and ignored (similar to banner ads on a website). This must be taken into account when designing the game, and strategizing the role each game element will have is of the utmost importance. This explains the relevance of empathizing with the user and working with a user experience expert when creating the game.Another important point is that there are many ways in which to bring about the same goal. Meaning a game designer can replace a given GE with completely different GEs, but ultimately will achieve the same outcome. For example, if the goal of the game was skills transfer, or teaching a user a new skill, one could apply: Quests: a complicated behavior can be learned over a stepwise fashion, which builds on specific components, and when put together can culminate in a learned skill on a boss level. Repetition: you could also use repetition to allow a user to practice multiple times until they gain memorizations38. Cut Scenes: would be able to explain a complicated behavior. All of these can demonstrate a new skill, but it is important to note that each of these GEs has varying degree of correlation between the element itself and skill transfer. For example, knowledge does not necessarily correlate to skill transfer, but it is important in the teaching process15. Interestingly, each of these GEs can be used separately, combined as all three, or some variation of that. Which combinations of GEs that most effectively drive a given behavior to change is not yet fully elucidated. One hindrance that has been echoed through this paper is the clear lack of consistent terms throughout this new field, which ultimately hinders the conductions of a meta-analysis on GEs efficacy. This controversy in the literature really emphasizes the need for a tool such as this one so the field can use common language at which to build games from. Even more so, we found that some papers not only neglected to associate GEs and theoretical frameworks, but also completely neglected to label the GEs used6,15. Therefore this tool can be used in a similar manner as a taxonomy. Meaning that the tool can be used to create a game, or use the definition pairs and BCGEEs provided to identify what is or is not a GE in other research or ones own game.

Future Research:One of the next steps for this research is to integrate GEs fun factor or acceptance amongst players into the tool to better provide the end users with an understanding of how the GE was received by the player during play. This additional information will allow researchers to see not only which GEEs were successful in changing behavior, but also which were successful in making a game more fun and engaging for users echoing the Entertainment Education approach12. This study is just the initial stages of a much larger endeavor. This was a proof of concept study to determine the best methodology for categorizing BCGEEs, GEs and pairing them with BCTs. Further research into the successful application of GE and BCGEEs within physical activity and nutrition education games is warranted because there are new health games entering the market each year. Newly identified games for health should be classified using this tool or methodology set forth for inclusion. This methodology can be applied to a variety of health topics and should be considered for greater ease of access to information for game designers looking to develop a successful game for health. See figure 3 for an example of how this tool can be applied to a cancer adherence game, called Remission-2. A next step for this tool will be its successful application to create a game for change. Currently, a startup company at the University of Central Florida College of Medicine lead by Co-Founders Alexander Eskandari, Zoran Pavlovic, and Brian Mayrsohn, has utilized this tool for the creation of their behavior change health app called, MotiveAte. Further testing to determine the effectiveness of that app will shed light on the role this tool can play in the development of future games for health.

8.0 Literature Cited 1.Foster, C. et al. Interventions for promoting physical activity ( Review ). 13 (2013). doi:10.1002/14651858.CD003180.pub2.Copyright2.Norman, G. J. et al. A review of eHealth interventions for physical activity and dietary behavior change. American journal of preventive medicine 33, 336345 (2007).3.Valente, T. W. Evaluating health promotion programs. (Oxford University Press New York, 2002).4.Fox, S. The % of internet users who have looked online for information about... Pew Research Center (2011). at 5.Fox, S. Peer-to-Peer health care. Pew Research Center (2011). at 6.Staiano, A. E., Abraham, A. a & Calvert, S. L. The Wii Club: Gaming for Weight Loss in Overweight and Obese Youth. Games for health journal 1, 377380 (2012).7.Errickson, S. P., Maloney, A. E., Thorpe, D., Giuliani, C. & Rosenberg, A. M. Dance Dance Revolution Used by 7- and 8-Year-Olds to Boost Physical Activity: Is Coaching Necessary for Adherence to an Exercise Prescription? Games for Health Journal 1, 4550 (2012).8.Maloney, A. E., Stempel, A., Wood, M. E., Patraitis, C. & Beaudoin, C. Can Dance Exergames Boost Physical Activity as a School-Based Intervention? Games for Health Journal 1, 416421 (2012).9.Buday, R., Lu, A. S. & Baranowski, J. Design of Video Games for Children s Diet and Physical Activity Behavior Change. 9, 317 (2009).10.Davies, C. a, Spence, J. C., Vandelanotte, C., Caperchione, C. M. & Mummery, W. K. Meta-analysis of internet-delivered interventions to increase physical activity levels. The international journal of behavioral nutrition and physical activity 9, 52 (2012).11.Baranowski, T., Baranowski, J. & Thompson, D. Video Game Play, Child Diet, and Physical Activity Behavior Change. American journal of preventive medicine 40, 3338 (2012).12.Peng, W. Design and evaluation of a computer game to promote a healthy diet for young adults. Health communication 24, 11527 (2009).13.Schneider, K. L. et al. Acceptability of an Online Health Videogame to Improve Diet and Physical Activity in Elementary School Students: Fitter Critters.Games for Health Journal 1, 262268 (2012).14.Cole, Steve (UCLA), Hopelab, the R. J. F. New Research Shows Zamzee Increases Physical Activity by Almost 60%. (2012). at 15.Thompson, Debbe, Baranowski, Tom, Buday, Richard, Baranowski, Janice, Thompson, Victoria, Jago, Russell, G. Serious Video Games for Health How Behavioral Science Guided Simul Gaming. Simul Gaming 41, 587606 (2010).16.Michie, S. & Prestwich, A. Are interventions theory-based? Development of a theory coding scheme. Health psychology: official journal of the Division of Health Psychology, American Psychological Association 29, 18 (2010).17.Green, M. C. & Brock, T. C. The role of transportation in the persuasiveness of public narratives. Journal of personality and social psychology 79, 701 (2000).18.Ryan, R. M. & Deci, E. L. Self-determination theory and the facilitation of intrinsic motivation, social development, and well-being. American psychologist 55, 68 (2000).19.Bandura, A. Influence of models reinforcement contingencies on the acquisition of imitative responses. Journal of personality and social psychology 1, 589 (1965).20.Nigg, C. R. Technologys influence on physical activity and exercise science: the present and the future. Psychology of Sport and Exercise 4, 5765 (2003).21.Atkinson, N. L. & Gold, R. S. The promise and challenge of eHealth interventions. American Journal of Health Behavior 26, 494503 (2002).22.McGonigal, J. Reality Is Broken: Why Games Make Us Better and How They Can Change the World. (Penguin Group, The, 2011).23.Bouman, M. The Turtle and the Peacock: collaboration for prosocial change: the entertainment - education strategy on television. (1999). at 24.Thompson, D., Cullen, K. W., Boushey, C. & Konzelmann, K. Design of a website on nutrition and physical activity for adolescents: results from formative research. Journal of medical Internet research 14, e59 (2012).25.Lu, A. S., Thompson, D., Baranowski, J., Buday, R. & Baranowski, T. Story Immersion in a Health Videogame for Childhood Obesity Prevention. Games for Health Journal 1, 3744 (2012).26.Riley, W. T. et al. Health behavior models in the age of mobile interventions: are our theories up to the last? Transl Behav Med 1, 5371 (2011).27.Petty, R. E., Briol, P. & Tormala, Z. L. Thought confidence as a determinant of persuasion: the self-validation hypothesis. Journal of personality and social psychology 82, 722 (2002).28.McGuire, W. J. Resistance to persuasion conferred by active and passive prior refutation of the same and alternative counterarguments. The Journal of Abnormal and Social Psychology 63, 326 (1961).29.Free, C. et al. The effectiveness of mobile-health technologies to improve health care service delivery processes: a systematic review and meta-analysis. PLoS medicine 10, e1001363 (2013).30.Metcalf, D. S. & Krohn, R. in Journal of medical Internet research 12, (2010).31.Abraham, C. & Michie, S. A taxonomy of behavior change techniques used in interventions. Health psychology: official journal of the Division of Health Psychology, American Psychological Association 27, 37987 (2008).32.Michie, S. et al. The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques: building an international consensus for the reporting of behavior change interventions. Annals of behavioral medicine: a publication of the Society of Behavioral Medicine 46, 8195 (2013).33.Rollings, Andrew and Adams, E. Fundamentals of Game Design. at 34.Lu, A. S., Kharrazi, H., Gharghabi, F. & Thompson, D. A Systematic Review of Health Videogames on Childhood Obesity Prevention and Intervention. Games for Health Journal 2, 131141 (2013).35.Phillips, C. A., Rolls, S., Rouse, A. & Griffiths, M. D. Home video game playing in schoolchildren: A study of incidence and patterns of play. Journal of Adolescence 18, 687691 (1995).36.Raessens, J. & Goldstein, J. H. Handbook of computer game studies. Artificial Intelligence xvii, 451 (2005).37.Mayrsohn, Brian and Khalil, G. in mHealth Innovation: Best Practices from the Mobile Frontier (Metcalf, David S and Krohn, R.) (HIMSS, 2013).38.Baranowski, T. et al. Structure of Corrective Feedback for Selection of Ineffective Vegetable Parenting Practices for Use in a Simulation Videogame. Games for Health Journal 2, 2933 (2013).

9.0 Appendix

See attached