In light of the obesity epidemic in persons with serious mental illness (SMI), there is an urgent need to scale-up behavioral interventions that have demonstrated efficacy in the clinical trial setting such as the intervention in the National Institute of Mental Health (NIMH)-funded Achieving Healthy Lifestyles in Psychiatric Rehabilitation (ACHIEVE) trial. To increase ease of adoption and sustained implementation of ACHIEVE in community mental health programs, the format needs to be adapted for delivery by community mental health staff. Based on the investigators' experience conducting the ACHIEVE trial, this study team had modified the ACHIEVE intervention into a new ACHIEVE curriculum appropriate for community mental health settings. Therefore, the investigators will pilot test 8 weeks of this curriculum in a community-based psychiatric rehabilitation program (PRP) to determine whether this format is acceptable to participating PRP consumers with SMI as well as PRP staff and peer leaders.

Prevalence of obesity is significantly elevated and a leading cause of preventable death in people with serious mental illness (SMI) through its effects on other cardiovascular disease (CVD) risk factors and CVD. Behavioral interventions targeting changes in diet and exercise need to be tailored to the needs of people with SMI, such as memory impairment and limited executive function. The NIMH-funded Achieving Healthy Lifestyles in Psychiatric Rehabilitation (ACHIEVE) trial tested a behavioral weight-loss intervention for persons with SMI and demonstrated clinically significant weight loss. In light of the obesity epidemic in persons with SMI, there is an urgent need to scale-up interventions like ACHIEVE. To increase ease of adoption and sustained implementation of ACHIEVE in community mental health programs, the format needs to be adapted for delivery by community mental health staff. Based on the investigators' experience conducting the ACHIEVE trial, this study team had modified the ACHIEVE intervention into a new ACHIEVE curriculum appropriate for community mental health settings. Therefore, the investigators will pilot test 8 weeks of this curriculum in a community-based psychiatric rehabilitation program (PRP) to determine whether this format is acceptable to participating PRP consumers with SMI as well as PRP staff and peer leaders.

Inclusion Criteria:

• aged 18 or older
• consumers at Prologue psychiatric rehabilitation program
• expected to be in the rehabilitation program for at least 6 months after enrollment
• able to attend the intervention classes 3 days per week
• able and willing to give informed consent and participate in the intervention
• have a body mass index (BMI) over 25 kg/m2
• be interested in losing weight

Exclusion Criteria:

• any underlying medical conditions that could seriously reduce life expectancy, ability to participate in the study, or for which dietary change or physical activity may be contraindicated and/or require medical supervision by a physician (e.g., medication-dependent diabetes mellitus, cancer or malignant tumor, lung disease requiring supplemental oxygen, dementia or cognitive impairment, consumption of more than 14 drinks per week, eating disorders, angina, or diagnosis in the last 12 months of myocardial infarction, congestive heart failure, transient ischemic attack or stroke, liver disease or kidney disease)
• women who are pregnant or breastfeeding
• individuals with an inability to walk to participate in exercise class as demonstrated by walking up and down 2 flights of stairs

2 months