title: Active video games as a tool to prevent excessive weight gain in adolescents: rationale, design and methods of a randomized controlled trial.
abstract: BACKGROUND
  Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games--i.e. active games--may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents.
  
  
  METHODS
  The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12-16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents' measured BMI-SDS (SDS=adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents' self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games.
  
  
  CONCLUSIONS
  This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents.
  
  
  BACKGROUND
  Dutch Trial register NTR3228.
authors.affiliation: Department of Health Sciences and the EMGO Institute for Health and Care Research, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands. m.simons@vu.nl.
authors.forename: Monique
authors.initials: M
authors.lastname: Simons
authors.forename: Mai J M
authors.initials: MJ
authors.lastname: Chinapaw
authors.forename: Maaike
authors.initials: M
authors.lastname: van de Bovenkamp
authors.forename: Michiel R
authors.initials: MR
authors.lastname: de Boer
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Seidell
authors.forename: Johannes
authors.initials: J
authors.lastname: Brug
authors.forename: Emely
authors.initials: E
authors.lastname: de Vet
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D063766:Pediatric Obesity / Q000517:prevention & control*; D010465:Perception; D012107:Research Design; D057185:Sedentary Behavior; D012885:Skinfold Thickness; D018910:Video Games; D055105:Waist Circumference; D015430:Weight Gain