OBJECTIVE: This study is aimed at the comparison between an individual and a group cognitive-behavioral program for the treatment of obesity. DESIGN: Parallel series, prospective, 3-year study. A group program of 10 weekly sessions focused on lifestyle modification was compared with a similar, individual 10-session program. Fifty-seven patients were assigned to individual treatment and 84 patients to the group program. SUBJECTS: One-hundred-forty-one obese female outpatients without binge eating disorder, aged 42.0 +/- 11.6 years (m +/- SD), with Body Mass Index (BMI) 37.3 +/- 5.2 kg/m(2). MEASUREMENTS: BMI and waist circumference were measured at 0, 6, 12 and 36 months. Analysis was performed on an intention-to-treat basis. RESULTS: Mean weight loss was superior with the group program at 6 months (2.0 +/- 3.9 vs 0.8 +/- 2.5 kg/m(2); p<0.05), while no difference between the two treatments was observed at 12 and 36 months. Mean waist circumference was significantly different at 6 months (group 97.4 +/- 2.5 vs individual 102.9 +/- 2.4, p<0.05), still remaining superior in the patients following individual treatment (100.2 +/- 5.0 vs 103.7 +/- 5.9) at 12 months, while no difference between the two treatments was observed at 36 months. The proportion of patients losing more than 5% of initial body weight with the group program (16.6, 15.5, and 38.1% at 6, 12, and 36 months, respectively) was not significantly different from that observed with individual treatment (5.3, 14.0, and 35.0%, respectively). CONCLUSION: A group cognitive-behavioral program for the treatment of obesity is not inferior to a similar program applied in individual setting, and it may enhance weight loss (especially fat mass, according to the waist measurement) in the short term. (Eating Weight Disord. 12: 147-153, 2007). (C) 2007, Editrice Kurtis