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A smartphone-supported weight loss program: design of the ENGAGED randomized controlled trial
Open Access Articles
  • Christine A. Pellegrini, Northwestern University
  • Jennifer M. Duncan, Northwestern University
  • Arlen C. Moller, Northwestern University
  • Joanna Buscemi, Northwestern University
  • Alyson Sularz, Northwestern University
  • Andrew DeMott, Northwestern University
  • Alex Pictor, Northwestern University
  • Sherry L. Pagoto, University of Massachusetts Medical School
  • Juned Siddique, Northwestern University
  • Bonnie J. Spring, Northwestern University
UMMS Affiliation
Department of Medicine, Division of Preventive and Behavioral Medicine
Publication Date
Document Type
Cellular Phone; Obesity; Weight Reduction Programs

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/DESIGN: 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.

DISCUSSION: 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. TRIAL REGISTRATION: NCT01051713.

Rights and Permissions
© 2012 Pellegrini et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
DOI of Published Version
BMC Public Health. 2012 Nov 30;12:1041. doi: 10.1186/1471-2458-12-1041. Link to article on publisher's site
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Citation Information
Christine A. Pellegrini, Jennifer M. Duncan, Arlen C. Moller, Joanna Buscemi, et al.. "A smartphone-supported weight loss program: design of the ENGAGED randomized controlled trial" Vol. 12 (2012) ISSN: 1471-2458 (Linking)
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