This study will test the utility of a social ecological theory, individually-targeted internet-based intervention with monetary incentives to reduce the weight of overweight and obese employees (INCENT) when compared to a low-intensity, internet-based weight loss program without incentives (Livin My Weigh). Participants in INCENT will receive daily e-mail support that facilitates goal setting, regular assessments of body weight, and incentives based on percent of original body weight lost at the end of each quarter over the 12-month program. The e-mail supports will target improving perceptions of self-efficacy and outcome expectations related to weight loss or maintaining a healthy weight. In addition e-mail support will facilitate participant problem solving and identification of resources for healthful eating and physical activity at home, in their neighborhoods, and at their worksite. Participants in Livin My Weigh (LMW)will receive evidence-based physical activity and nutrition information to facilitate weight loss through quarterly newsletters and quarterly educational sessions.