Lifestyle Intervention for Young Adults With Serious Mental Illness

The objective of this study is to evaluate the effectiveness of a group-based lifestyle intervention (PeerFIT) supported by mobile health (mHealth) technology and social media to promote weight loss and improved fitness in young adults with serious mental illness (SMI). The study is a two-arm randomized controlled trial conducted in real world mental health settings to evaluate the effectiveness of the 12-month PeerFIT intervention compared to Basic Education in fitness and nutrition supported by a wearable Activity Tracking device (BEAT) in achieving clinically significant improvements in weight loss and cardiorespiratory fitness. The investigators will enroll 144 overweight and obese (BMI ≥ 25) young adults ages 18 to 35 with SMI attending one of two community mental health who are interested in losing weight and improving fitness. The investigators hypothesize that PeerFIT compared to BEAT will be associated with a greater proportion of participants who achieve cardiovascular risk reduction at 6 and 12 months follow-up as indicated by either clinically significant weight loss (5% or greater) or increased fitness (\>50 m on the six-minute walk test). The investigators also hypothesize that PeerFIT compared to BEAT will be associated with greater improvements in A1c and lipid profiles at 6 and 12 months follow-up. They will also investigate two theoretical mechanisms of action hypothesized to account for greater weight loss and increased cardiorespiratory fitness among participants assigned to PeerFIT: 1) improved self-efficacy and 2) increased peer support for health behavior change. The investigators hypothesize that the relationship between PeerFIT and weight loss and improved fitness will be mediated by improved self-efficacy and peer support for health behavior change.