BACKGROUND: Understanding the factors that influence successful weight control is critical for developing interventions. PURPOSE: The purpose of the study was to provide a comprehensive understanding of the role of psychosocial, environmental, and behavioral variables in distinguishing weight-loss maintainers (WLM) from treatment-seeking obese (TSO). METHODS: WLM (n = 167) had lost >/=10% of their maximum body weight, had kept the weight off for >/=5 years, and were now of normal weight. TSO-1 and TSO-2 had a history of dieting and body mass index >/=25. TSO-1 was predominantly Caucasian; TSO-2 was predominantly African-American. Bayesian model averaging was used to identify the variables that distinguished WLM from TSO-1 and TSO-2. RESULTS: The variables that most consistently discriminated WLM from TSO were more physical activity (ORs = 3.95 and 2.85), more dietary restraint (ORs = 1.63 and 1.41), and less dietary disinhibition (ORs = 0.69 and 0.83). Environmental variables, including the availability of physical activity equipment, TVs, and high-fat foods in the home, also distinguished WLM from TSO. CONCLUSIONS: Obesity treatment should focus on increasing conscious control over eating, engaging in physical activity, and reducing disinhibition. Changes in the home environment may help facilitate these behavioral changes.