Weight change and mental health status in a behavioral weight loss trial

Background: Obesity, depression, and anxiety often co-occur, but research on weight change and mental health status is limited. This analysis examined how the mental component score (MCS-12) from the Short Form health survey changed over 24 months in weight loss trial participants with vs. without treatment seeking for affective symptoms (TxASx) and by weight change quintiles.Methods: Participants with complete data (n = 1163) were analyzed from enrollees in a cluster-randomized, behavioral weight loss trial in rural U.S. Midwestern primary care practices. Participants received a lifestyle intervention with different delivery models, including in-clinic individual, in-clinic group, or telephone group counseling visits. Participants were stratified by baseline TxASx status and 24-month weight change quintiles. Mixed models were used to estimate MCS-12 scores.Results: There was a significant group-by-time interaction at the 24-month follow-up. The largest 0-24 month increase in MCS-12 scores (+5.3 points [12 %]) was observed in participants with TxASx who lost the most weight during the trial, while the largest decrease in MCS-12 scores (-1.8 points [-3 %]) was observed in participants without TxASx who gained the most weight (p < 0.001). Limitations: Notable limitations included self-reported mental health, the observational analytical design, and a largely homogenous source population, as well as the possibility of reverse causation biasing some findings.Conclusions: Mental health status generally improved, particularly among participants with TxASx who experi-enced significant weight loss. Those without TxASx who gained weight, however, had a decline in mental health status over 24 months. Replication of these findings is warranted.