An initial evaluation of a commercial weight loss program: Short-term effects on weight, eating behavior, and mood

Objective: This paper describes an initial, 4-week evaluation of a commercial weight loss program. Research Methods and Procedures: Respondents (n = 985) to newspaper advertisements in two metropolitan areas were assigned to 4 weeks of either the Weight Watchers program or to a Self-Help condition. Weight loss, psychological vitality, and eating behavior were evaluated before and after the 4-week intervention, Results: Weight Watchers participants showed greater improvements than Self-Help participants on all measures; weight losses averaged 1.87 and 0.77 kg, respectively. The superior outcomes shown by Weight Watchers participants on measures of vitality and eating behavior were still evident when extent of weight loss was controlled. Weight losses across different sites, incomes, and levels of obesity were similar. Discussion: Although the present study's intervention and outcome assessments were short-term, the promising results obtained suggest that longer term studies should be undertaken.