 A total of 182 women and men with a BMI 33 and 55 kgm2, without co-morbidities, or 30 and 55 kgm2 with a co-morbid cardiovascular disease CVD condition will be enrolled in the 4-month run-in period. Prior to enrollment, all participants will have a history, physical exam, electrocardiogram EKG, and appropriate blood tests. They will attend weekly group sessions for 14 weeks. Participants will have a brief medical visit at week 8 to check their health and blood tests will be repeated. The investigators anticipate that 136 75 participants will lose 5 or more of initial weight and qualify for randomization. Participants who do not lose 5 will be provided a list of weight loss resources e.g., other programs to facilitate their continued weight management. 