High attrition rates in commercial weight reduction programs.

The management of obesity is increasingly dominated by nonprofessional self-helping groups. Little information about the efficacy of these groups is available from independent sources. In a study of 108 women enrolled in a commercial weight reduction program, we found very high attrition rates; 50% of the members dropped out in six weeks and 70% in 12 weeks. Similar attrition rates have been reported in five other programs in three different countries. Very high attrition rates diminish the effectiveness of commercial weight reduction programs, and they suggest caution in the interpretation of data based on weight losses of persons who remain in these programs.