title: Adherence to a smartphone application for weight loss compared to website and paper diary: pilot randomized controlled trial.
abstract: BACKGROUND
  There is growing interest in the use of information communication technologies to treat obesity. An intervention delivered by smartphone could be a convenient, potentially cost-effective, and wide-reaching weight management strategy. Although there have been studies of texting-based interventions and smartphone applications (apps) used as adjuncts to other treatments, there are currently no randomized controlled trials (RCT) of a stand-alone smartphone application for weight loss that focuses primarily on self-monitoring of diet and physical activity.
  
  
  OBJECTIVE
  The aim of this pilot study was to collect acceptability and feasibility outcomes of a self-monitoring weight management intervention delivered by a smartphone app, compared to a website and paper diary.
  
  
  METHODS
  A sample of 128 overweight volunteers were randomized to receive a weight management intervention delivered by smartphone app, website, or paper diary. The smartphone app intervention, My Meal Mate (MMM), was developed by the research team using an evidence-based behavioral approach. The app incorporates goal setting, self-monitoring of diet and activity, and feedback via weekly text message. The website group used an existing commercially available slimming website from a company called Weight Loss Resources who also provided the paper diaries. The comparator groups delivered a similar self-monitoring intervention to the app, but by different modes of delivery. Participants were recruited by email, intranet, newsletters, and posters from large local employers. Trial duration was 6 months. The intervention and comparator groups were self-directed with no ongoing human input from the research team. The only face-to-face components were at baseline enrollment and brief follow-up sessions at 6 weeks and 6 months to take anthropometric measures and administer questionnaires.
  
  
  RESULTS
  Trial retention was 40/43 (93%) in the smartphone group, 19/42 (55%) in the website group, and 20/43 (53%) in the diary group at 6 months. Adherence was statistically significantly higher in the smartphone group with a mean of 92 days (SD 67) of dietary recording compared with 35 days (SD 44) in the website group and 29 days (SD 39) in the diary group (P<.001). Self-monitoring declined over time in all groups. In an intention-to-treat analysis using baseline observation carried forward for missing data, mean weight change at 6 months was -4.6 kg (95% CI -6.2 to -3.0) in the smartphone app group, -2.9 kg (95% CI -4.7 to -1.1) in the diary group, and -1.3 kg (95% CI -2.7 to 0.1) in the website group. BMI change at 6 months was -1.6 kg/m(2) (95% CI -2.2 to -1.1) in the smartphone group, -1.0 kg/m(2) (95% CI -1.6 to -0.4) in the diary group, and -0.5 kg/m(2) (95% CI -0.9 to 0.0) in the website group. Change in body fat was -1.3% (95% CI -1.7 to -0.8) in the smartphone group, -0.9% (95% CI -1.5 to -0.4) in the diary group, and -0.5% (95% CI -0.9 to 0.0) in the website group.
  
  
  CONCLUSIONS
  The MMM app is an acceptable and feasible weight loss intervention and a full RCT of this approach is warranted.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01744535; http://clinicaltrials.gov/ct2/show/NCT01744535 (Archived by WebCite at http://www.webcitation.org/6FEtc3PVB).
authors.affiliation: Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom. m.carter@leeds.ac.uk
authors.forename: Michelle Clare
authors.initials: MC
authors.lastname: Carter
authors.forename: Victoria Jane
authors.initials: VJ
authors.lastname: Burley
authors.forename: Camilla
authors.initials: C
authors.lastname: Nykjaer
authors.forename: Janet Elizabeth
authors.initials: JE
authors.lastname: Cade
mesh_terms: D000328:Adult; D040421:Cell Phone; D015930:Diet Records; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009765:Obesity / Q000178:diet therapy* / Q000473:pathology; D010342:Patient Acceptance of Health Care; D010349:Patient Compliance; D010865:Pilot Projects; D017216:Telemedicine / Q000379:methods*; D061217:Weight Reduction Programs / Q000379:methods*