title: A smartphone-supported weight loss program: design of the ENGAGED randomized controlled trial.
abstract: BACKGROUND
  Obesity remains a major public health challenge, demanding cost-effective and scalable weight management programs. Delivering key treatment components via mobile technology offers a potential way to reduce expensive in-person contact, thereby lowering the cost and burden of intensive weight loss programs. The ENGAGED study is a theory-guided, randomized controlled trial designed to examine the feasibility and efficacy of an abbreviated smartphone-supported weight loss program.
  
  
  METHODS
  Ninety-six obese adults (BMI 30-39.9 kg/m2) will be randomized to one of three treatment conditions: (1) standard behavioral weight loss (STND), (2) technology-supported behavioral weight loss (TECH); or (3) self-guided behavioral weight loss (SELF). All groups will aim to achieve a 7% weight loss goal by reducing calorie and fat intake and progressively increasing moderate intensity physical activity to 175 minutes/week. STND and TECH will attend 8 group sessions and receive regular coaching calls during the first 6 months of the intervention; SELF will receive the Group Lifestyle Balance Program DVD's and will not receive coaching calls. During months 1-6, TECH will use a specially designed smartphone application to monitor dietary intake, body weight, and objectively measured physical activity (obtained from a Blue-tooth enabled accelerometer). STND and SELF will self-monitor on paper diaries. Linear mixed modeling will be used to examine group differences on weight loss at months 3, 6, and 12. Self-monitoring adherence and diet and activity goal attainment will be tested as mediators.
  
  
  CONCLUSIONS
  ENGAGED is an innovative weight loss intervention that integrates theory with emerging mobile technologies. We hypothesize that TECH, as compared to STND and SELF, will result in greater weight loss by virtue of improved behavioral adherence and goal achievement.
  
  
  BACKGROUND
  NCT01051713.
authors.affiliation: Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, 680 N, Lake Shore Drive, Suite 1400, Chicago, IL 60611, USA. c-pellegrini@northwestern.edu
authors.forename: Christine A
authors.initials: CA
authors.lastname: Pellegrini
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Duncan
authors.forename: Arlen C
authors.initials: AC
authors.lastname: Moller
authors.forename: Joanna
authors.initials: J
authors.lastname: Buscemi
authors.forename: Alyson
authors.initials: A
authors.lastname: Sularz
authors.forename: Andrew
authors.initials: A
authors.lastname: DeMott
authors.forename: Alex
authors.initials: A
authors.lastname: Pictor
authors.forename: Sherry
authors.initials: S
authors.lastname: Pagoto
authors.forename: Juned
authors.initials: J
authors.lastname: Siddique
authors.forename: Bonnie
authors.initials: B
authors.lastname: Spring
mesh_terms: D000293:Adolescent; D000328:Adult; D040421:Cell Phone; D005240:Feasibility Studies; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000517:prevention & control*; D015397:Program Evaluation; D011582:Psychological Theory; D012107:Research Design; D012648:Self Care; D061217:Weight Reduction Programs / Q000379:methods*; D055815:Young Adult