An Internet-based weight loss programme -- a feasibility study with preliminary results from 4209 completers

1. To identify characteristics of individuals seeking help for their weight problem via an internet-based programme. 2. To identify indicators of long term success in such a programme.

An internet-based weight club (www.viktklubb.se) was used consisting of standard algorithms for calculating body mass index (BMI), food energy content and exercise energy cost. All members filled in basic data and could volunteer to fill in additional research related questions. Together with data on treatment success, attrition, and use of the various components of the programme, this information was automatically monitored and downloaded to a database.

Eighty-six percent of the members were female, and the age range was wide (range 18-101 years; mean 40.3 +/-11.5 years). At baseline, BMI of the entire group was 29.3 +/-5.1 kg/m(2) with 39% obese and 45% overweight. Among the completers, 16% changed from overweight or obese to normal weight. This corresponded to 29% of the members losing 5-9.9% of their initial body weight and 20% losing > or =10% of their. The strongest predictors of weight loss were activity in the weight club as judged by number of logins and diary entries, and sex.

A sizeable, but seemingly random, dropout rate was observed, together with significant dose-response effects between activity in the internet-based program and weight-loss among completers. Given its low cost and high accessibility at 24 hours a day, this form of programme delivery is interesting to evaluate and develop further, especially regarding attrition.