title: Effect of Web-based lifestyle modification on weight control: a meta-analysis.
abstract: OBJECTIVE
  Web-based treatment programs are attractive in primary care because of their ability to reach numerous individuals at low cost. Our aim of this meta-analysis is to systematically review the weight loss or maintenance effect of the Internet component in obesity treatment programs.
  
  
  METHODS
  MEDLINE and EMBASE literature searches were conducted to identify studies investigating the effect of Web-based individualized advice on lifestyle modification on weight loss. Randomized controlled trials that consisted of a Web-user experimental and non-Web user control group were included. Weight changes in the experimental group in comparison with the control group were pooled with a random-effects model.
  
  
  RESULTS
  A total of 23 studies comprising 8697 participants were included. Overall, using the Internet had a modest but significant additional weight-loss effect compared with non-Web user control groups (-0.68 kg, P=0.03). In comparison with the control group, stratified analysis indicated that using the Internet as an adjunct to obesity care was effective (-1.00 kg, P<0.001), but that using it as a substitute for face-to-face support was unfavorable (+1.27 kg, P=0.01). An additional effect on weight control was observed when the aim of using the Internet was initial weight loss (-1.01 kg; P=0.03), but was not observed when the aim was weight maintenance (+0.68 kg; P=0.26). The relative effect was diminished with longer educational periods (P-trend=0.04) and was insignificant (-0.20 kg; P=0.75) in studies with educational periods of 12 months or more.
  
  
  CONCLUSIONS
  The current meta-analysis indicates that the Internet component in obesity treatment programs has a modest effect on weight control. However, the effect was inconsistent, largely depending on the type of usage of the Internet or the period of its use.
authors.affiliation: Department of Internal Medicine, University of Tsukuba Institute of Clinical Medicine, Mito, Ibaraki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kodama
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: C
authors.initials: C
authors.lastname: Horikawa
authors.forename: K
authors.initials: K
authors.lastname: Fujiwara
authors.forename: R
authors.initials: R
authors.lastname: Hirasawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yachi
authors.forename: K T
authors.initials: KT
authors.lastname: Iida
authors.forename: H
authors.initials: H
authors.lastname: Shimano
authors.forename: Y
authors.initials: Y
authors.lastname: Ohashi
authors.forename: N
authors.initials: N
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Sone
mesh_terms: D001835:Body Weight; D005260:Female; D015438:Health Behavior; D006293:Health Promotion; D006801:Humans; D020407:Internet / Q000706:statistics & numerical data*; D008297:Male; D009765:Obesity / Q000517:prevention & control*; D011320:Primary Health Care; D016032:Randomized Controlled Trials as Topic; D040242:Risk Reduction Behavior; D012648:Self Care; D015431:Weight Loss