Obesity and metabolic disturbances frequently occur in individuals with psychiatric disorders. This study evaluates a telephonically delivered lifestyle coaching intervention aimed at weight reduction and wellness improvement in psychiatric outpatients. A cohort of 761 participants was prospectively followed up for a period of 12 months. Lifestyle coaching was administered telephonically on a weekly basis for the first 3 months and monthly thereafter. During the study period, there was a significant reduction in weight and waist circumference as well as a significant increase in general health in the completer group. A total of 46% of the participants lost 5% or more of their baseline weight. Significant predictors of attrition at baseline were the presence of metabolic syndrome, younger age, chronic illness, and the diagnosis of a mood disorder. Dropout was significantly less in those participants who received support from a nominated caregiver. Telephonic lifestyle coaching is feasible in this population.