@Article{info:doi/10.2196/jmir.2648,
author="Postrach, Elisa
and Aspalter, Rosa
and Elbelt, Ulf
and Koller, Michael
and Longin, Rita
and Schulzke, J{\"o}rg-Dieter
and Valentini, Luzia",
title="Determinants of Successful Weight Loss After Using a Commercial Web-Based Weight Reduction Program for Six Months: Cohort Study",
journal="J Med Internet Res",
year="2013",
month="Oct",
day="14",
volume="15",
number="10",
pages="e219",
keywords="Internet; weight loss; overweight; obesity; weight reduction program; efficiency; program evaluation; preventive health services; sex",
abstract="Background: The Internet is widely available and commonly used for health information; therefore, Web-based weight loss programs could provide support to large parts of the population in self-guided weight loss. Previous studies showed that Web-based weight loss interventions can be effective, depending on the quality of the program. The most effective program tools are visual progress charts or tools for the self-monitoring of weight, diet, and exercises. KiloCoach, a commercial program currently available in German-speaking countries, incorporates these features. A previous investigation showed that the program effectively supports users in losing weight. Objective: We investigated weight loss dynamics stratified by weight loss success after 6-month use of KiloCoach. Furthermore, we analyzed possible associations between intensity of program use and weight loss. The results are intended for tailoring user recommendations for weight-loss Internet platforms. Methods: Datasets of KiloCoach users (January 1, 2008 to December 31, 2011) who actively used the platform for 6 months or more were assigned to this retrospective analysis. Users (N=479) were 42.2{\%} men, mean age of 44.0 years (SD 11.7), with a mean body mass index (BMI) of 31.7 kg/m2 (SD 3.2). Based on the weight loss achieved after 6 months, 3 success groups were generated. The unsuccessful group lost <5{\%}, the moderate success group lost 5{\%}-9.9{\%}, and the high success group lost ≥10{\%} of their baseline body weight. At baseline, the unsuccessful (n=261, 54.5{\%}), moderate success (n=133, 27.8{\%}), and high success (n=85, 17.8{\%}) groups were similar in age, weight, BMI, and gender distribution. Results: After 6 months, the unsuccessful group lost 1.2{\%} (SD 2.4), the moderate success group lost 7.4{\%} (SD 1.5), and the high success group lost 14.2{\%} (SD 3.8) of their initial weight (P<.001). Multivariate regression showed that early weight loss (weeks 3-4), the total number of dietary protocols, and the total number of weight entries were independent predictors for 6-month weight reduction (all P<.001) explaining 52{\%} of the variance in weight reduction. Sensitivity analysis by baseline carried forward method confirmed all independent predictors of 6-month weight loss and reduced the model fit by only 11{\%}. The high success group lost weight faster and maintained weight loss more efficiently than the other groups (P<.001). Early weight loss was associated with weight maintenance after 1 year and 2 years (both P<.001). Weight dynamics did not differ between men and women over 6 months when adjusted for baseline and usage parameters (P=.91). The percentage of male long-term users was unusually high (42.2{\%}). Conclusions: Our results suggest that early weight loss and close program adherence (ie, 5 dietary protocols per week and weekly entering of current weight), especially in the early phase of program usage, can improve weight loss outcome. ",
issn="14388871",
doi="10.2196/jmir.2648",
url="http://www.jmir.org/2013/10/e219/",
url="https://doi.org/10.2196/jmir.2648",
url="http://www.ncbi.nlm.nih.gov/pubmed/24126250"
}