title: Effects of Playing a Serious Computer Game on Body Mass Index and Nutrition Knowledge in Women.
abstract: BACKGROUND
  Obesity and weight gain is a critical public health concern. Serious digital games are gaining popularity in the context of health interventions. They use persuasive and fun design features to engage users in health-related behaviors in a non-game context. As a young field, research about effectiveness and acceptability of such games for weight loss is sparse.
  
  
  OBJECTIVE
  The goal of this study was to evaluate real-world play patterns of SpaPlay and its impact on body mass index (BMI) and nutritional knowledge. SpaPlay is a computer game designed to help women adopt healthier dietary and exercise behaviors, developed based on Self-Determination theory and the Player Experience of Need Satisfaction (PENS) model. Progress in the game is tied to real-life activities (e.g., eating a healthy snack, taking a flight of stairs).
  
  
  METHODS
  We recruited 47 women to partake in a within-subject 90-day longitudinal study, with assessments taken at baseline, 1-, 2-, and 3- months. Women were on average, 29.8 years old (±7.3), highly educated (80.9% had BA or higher), 39% non-White, baseline BMI 26.98 (±5.6), who reported at least contemplating making changes in their diet and exercise routine based on the Stages of Change Model. We computed 9 indices from game utilization data to evaluate game play. We used general linear models to examine inter-individual differences between levels of play, and multilevel models to assess temporal changes in BMI and nutritional knowledge.
  
  
  RESULTS
  Patterns of game play were mixed. Participants who reported being in the preparation or action stages of behavior change exhibited more days of play and more play regularity compared to those who were in the contemplation stage. Additionally, women who reported playing video games 1-2 hours per session demonstrated more sparse game play. Brief activities, such as one-time actions related to physical activity or healthy food, were preferred over activities that require a longer commitment (e.g., taking stairs every day for a week). BMI decreased significantly (P<.001) from baseline to 3-month follow-up, yielding a large effect size of 1.28. Nutritional knowledge increased significantly (P<.001) from first to third month follow-ups, with an effect size of .86. The degree of change in both outcomes was related to game play, baseline readiness to change, and the extent of video game play in general.
  
  
  CONCLUSIONS
  This work demonstrates initial evidence of success for using a serious game as an intervention for health behavior change in real world settings. Our findings also highlight the need to understand not only game effectiveness but also inter-individual differences. Individualizing content and the intervention medium appears to be necessary for a more personalized and long-lasting impact.
authors.affiliation: Northeastern University, Applied Psychology, Boston, MA, United States. m.shiyko@neu.edu.
authors.forename: Mariya
authors.identifier: http://orcid.org/0000-0002-4930-7041
authors.initials: M
authors.lastname: Shiyko
authors.forename: Sean
authors.identifier: http://orcid.org/0000-0003-0287-6914
authors.initials: S
authors.lastname: Hallinan
authors.forename: Magy
authors.identifier: http://orcid.org/0000-0002-7808-1686
authors.initials: M
authors.lastname: Seif El-Nasr
authors.forename: Shree
authors.identifier: http://orcid.org/0000-0002-9232-4568
authors.initials: S
authors.lastname: Subramanian
authors.forename: Carmen
authors.identifier: http://orcid.org/0000-0001-5293-3070
authors.initials: C
authors.lastname: Castaneda-Sceppa
keywords: Player Experience of Need Satisfaction (PENS) model; body mass index; game play; games for health; nutritional knowledge; self-determination theory; serious games; weight loss; women