To compare group behavior therapy with individual behavior therapy for promoting healthy dieting behavior and weight control in overweight and obese women in rural community.

This parallel group, open labeled, randomized non-inferiority trial was conducted from March 2005 to April 2006. A total of 132 overweight and obese women with a mean (S.D.) age of 38.4 (7.9) years and body mass index (BMI) of 28.9 (2.9)kg/m² were randomly assigned to receive either group behavior therapy (n=65) or individual behavior therapy (n=67). Five intervention sessions were provided biweekly during the 3-month period. Assessments were conducted at months 3, 6, and 12. Primary outcome was mean percentage weight loss at month 6. Other outcomes included anthropometric outcomes, dietary intake, healthy dieting behavior, intention, perceived behavioral control, attitude, and subjective norm.

Mean percentage weight loss at month 6 of group behavior therapy was comparable to individual behavior therapy (5.9% (95%CI: 4.5–7.3) versus 5.4% (95%CI: 4.0–6.7)); P=0.027 for non-inferiority at one sided 0.05 level of significance. Other outcomes were remarkably similar between the two study groups. Attitude, subjective norm, and perceived behavioral control improved slightly; whereas, intention, healthy dieting behavior, and dietary intake improved significantly after interventions. High intention and perceived behavioral control was related to greater weight loss. At 1 year, 73% of participants either lost or maintained their weight. Anthropometric outcomes and healthy dieting behavior were significantly better than baseline.

Group behavior therapy was not inferior to individual behavior therapy, and it should be used as the first line mode of behavior therapy for weight control management in a rural community.