 Objectives: The investigators on this proposal previously developed a prototype web-based system that provides limited diet education to individuals with SMI. The current project extends and evaluates this system. The projects objectives are to: 1 build on the prototype to develop eWellness, a comprehensive web-based system that delivers an evidence-based weight management program focused on diet and activity, and that meets the needs of individuals with SMI; 2 evaluate the effectiveness, in individuals with SMI, of an eWellness program compared with a control group; and, 3 characterize, from the perspective of individuals with SMI, the strengths, weaknesses, and barriers to the use of eWellness. 