Study protocol for Log2Lose: A feasibility randomized controlled trial to evaluate financial incentives for dietary self-monitoring and interim weight loss in adults with obesity.

Journal Article (Journal Article)

The obesity epidemic has negative physical, psychological, and financial consequences. Despite the existence of effective behavioral weight loss interventions, many individuals do not achieve adequate weight loss, and most regain lost weight in the year following intervention. We report the rationale and design for a 2×2 factorial study that involves financial incentives for dietary self-monitoring (yes vs. no) and/or interim weight loss (yes vs. no). Outpatients with obesity participate in a 24-week, group-based weight loss intervention. All participants are asked to record their daily dietary and liquid intake on a smartphone application (app) and to weigh themselves daily at home on a study-provided cellular scale. An innovative information technology (IT) solution collates dietary data from the app and weight from the scale. Using these data, an algorithm classifies participants weekly according to whether they met their group's criteria to receive a cash reward ranging from $0 to $30 for dietary self-monitoring and/or interim weight loss. Notice of the reward is provided via text message, and credit is uploaded to a gift card. This pilot study will provide information on the feasibility of using this novel IT solution to provide variable-ratio financial incentives in real time via its effects on recruitment, intervention adherence, retention, and cost. This study will provide the foundation for a comprehensive, adequately-powered, randomized controlled trial to promote short-term weight loss and long-term weight maintenance. If efficacious, this approach could reduce the prevalence, adverse outcomes, and costs of obesity for millions of Americans. registration: NCT02691260.

Full Text

Duke Authors

Cited Authors

  • Voils, CI; Levine, E; Gierisch, JM; Pendergast, J; Hale, SL; McVay, MA; Reed, SD; Yancy, WS; Bennett, G; Strawbridge, EM; White, AC; Shaw, RJ

Published Date

  • February 2018

Published In

Volume / Issue

  • 65 /

Start / End Page

  • 116 - 122

PubMed ID

  • 29289702

Pubmed Central ID

  • PMC5803330

Electronic International Standard Serial Number (EISSN)

  • 1559-2030

Digital Object Identifier (DOI)

  • 10.1016/j.cct.2017.12.007


  • eng

Conference Location

  • United States