Purpose of review: It is beyond dispute that people living with mental illness suffer a disproportionate disease burden when compared with people in the general population. This review considers the efficacy and effectiveness of lifestyle behavioural interventions at service delivery level as a strategy to reduce the risk factors that contribute to somatic disease comorbidity. As many factors contribute to the very poor physical health of people living with mental illness and as there are no 'quick fix' remedies, strategies to improve physical health need to be sustainable on a system-wide basis.Recent findings: Most studies of behavioural interventions at best report modest success during the period of the intervention. However, even limited success can significantly reduce the likelihood of physical comorbidities developing. Unfortunately, the evidence suggests that any gains during the intervention are mostly lost over time. The implication is that interventions need to be sustainable over the long-term.Summary: When planning behavioural interventions, consideration ought to be given to extending them over a period of years not weeks or months. Approaches that include additional on-going support beyond the intervention period itself promote a greater likelihood of maintaining the improved physical health of the target population.