title: Mobile Phone Apps to Promote Weight Loss and Increase Physical Activity: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  To our knowledge, no meta-analysis to date has assessed the efficacy of mobile phone apps to promote weight loss and increase physical activity.
  
  
  OBJECTIVE
  To perform a systematic review and meta-analysis of studies to compare the efficacy of mobile phone apps compared with other approaches to promote weight loss and increase physical activity.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of relevant studies identified by a search of PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Scopus from their inception through to August 2015. Two members of the study team (EG-F, GF-M) independently screened studies for inclusion criteria and extracted data. We included all controlled studies that assessed a mobile phone app intervention with weight-related health measures (ie, body weight, body mass index, or waist circumference) or physical activity outcomes. Net change estimates comparing the intervention group with the control group were pooled across studies using random-effects models.
  
  
  RESULTS
  We included 12 articles in this systematic review and meta-analysis. Compared with the control group, use of a mobile phone app was associated with significant changes in body weight (kg) and body mass index (kg/m(2)) of -1.04 kg (95% CI -1.75 to -0.34; I2 = 41%) and -0.43 kg/m(2) (95% CI -0.74 to -0.13; I2 = 50%), respectively. Moreover, a nonsignificant difference in physical activity was observed between the two groups (standardized mean difference 0.40, 95% CI -0.07 to 0.87; I2 = 93%). These findings were remarkably robust in the sensitivity analysis. No publication bias was shown.
  
  
  CONCLUSIONS
  Evidence from this study shows that mobile phone app-based interventions may be useful tools for weight loss.
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària (IDIAP) Jordi Gol, Reus, Spain. gemmaflores@gmail.com.
authors.forename: Gemma
authors.identifier: http://orcid.org/0000-0001-6901-7327
authors.initials: G
authors.lastname: Flores Mateo
authors.forename: Esther
authors.identifier: http://orcid.org/0000-0002-4484-6054
authors.initials: E
authors.lastname: Granado-Font
authors.forename: Carme
authors.identifier: http://orcid.org/0000-0001-5229-0394
authors.initials: C
authors.lastname: Ferré-Grau
authors.forename: Xavier
authors.identifier: http://orcid.org/0000-0003-4103-7101
authors.initials: X
authors.lastname: Montaña-Carreras
mesh_terms: D040421:Cell Phone / Q000706:statistics & numerical data*; D006801:Humans; D063731:Mobile Applications / Q000706:statistics & numerical data*; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000628:therapy*; D015431:Weight Loss / Q000502:physiology*
keywords: apps; intervention; mHealth; mobile phone; obesity; physical activity