Effectiveness of a Lifestyle Intervention for People With a Severe Mental Illness in Dutch Outpatient Mental Health Care: A Randomized Clinical Trial.

Importance: People with a severe mental illness (SMI) have a life expectancy reduced by 10 to 20 years compared with the general population, primarily attributable to cardiometabolic disorders. Lifestyle interventions for people with SMI can improve health and reduce cardiometabolic risk.

Objective: To evaluate the effectiveness of a group-based lifestyle intervention among people with SMI in outpatient treatment settings compared with treatment as usual (TAU).