The study population consisted of overweight or obese adults (≥18 years of age) who attended 1 of 10 community psychiatric rehabilitation programs in central Maryland or their affiliated outpatient mental health clinics. The eligibility criteria were minimal; we aimed to enroll a broad population that would be representative of persons with serious mental illness attending community mental health programs.39 We excluded persons with a medical contraindication to weight loss, a cardiovascular event within the previous 6 months, an inability to walk, or an active alcohol-use or substance-use disorder (see the Supplementary Appendix, available at NEJM.org).