Despite enormous public health efforts, heart disease remains the number one killer, partly due to the prevalence of high dietary fat intake and sedentary lifestyles. At the same time and for many of the same reasons, obesity is becoming increasingly prevalent, bringing with it increased risk of heart disease, hypercholesterolemia, diabetes, hypertension, and some forms of cancer. In an effort to address the dietary behaviors that promote both heart disease and obesity, Health Management Consultants of Virginia proposes to develop Get-the-Fat-Out, an Internet data based behavior modification program targeted for at-risk adults at varying stages of readiness for changing dietary fat intake and physical activity level. The ultimate goal of Get-the-Fat-Out is to facilitate life-long habits of maintaining a healthy weight, an active lifestyle, and a low-fat diet. Specific aims for Phase I are: 1) Develop initial and on going "intervention-integrated" readiness for change assessments; 2) Develop stage-specific contents and strategies; 3) Develop a reward system; 4) Program 1, 2 and 3 for delivery on-line via PC and/or PDA; 5) Formatively evaluate the program. Get-the-Fat-Out could be offered to adults as part of a cardiac rehabilitation or other disease management or wellness program, or as an independent intervention via on-line subscription.